KAWASAKI Tsutomu

Researcher Information

Degree

• Ph.D.

URL

http://nara-kindai.unv.jp/02gakka/interview-staff/ivs06-15.html

J-Global ID

• 200901084467662071

Research Areas

• Environmental science/Agricultural science / Conservation science (plants)
• Environmental science/Agricultural science / Plant genetics and breeding
• Life sciences / Plants: molecular biology and physiology
• Life sciences / Ecology and environmental science

Academic & Professional Experience

• 2010 - Today  Kindai UniversityFaculty of Agriculture教授
• 2007 - 2010  Nara Institute of Science and TechnologyGraduate School of Biological Sciences准教授
• 2002 - 2007  Nara Institute of Science and TechnologyGraduate School of Biological Sciences助教授
• 2000 - 2002  ノースカロライナ大学チャペルヒル校理学部文部科学省・在外研究員
• 1996 - 2000  Nara Institute of Science and TechnologyGraduate School of Biological Sciences助手
• 1990 - 1996  （株）三井業際植物バイオ研究所

Education

• 1988/04 - 1990/03  Kyushu University  農学研究科  農学専攻修士課程
• 1984/04 - 1988/03  Kyushu University  School of Agriculture  農学科

Association Memberships

• American Society of plant Physiologist   International society of Molecular Plant Microbe Interaction   日本農芸化学学会   日本植物生理学会   日本植物病理学会   日本育種学会   日本分子生物学会   

Published Papers

• The rice OsERF101 transcription factor regulates the NLR Xa1-mediated immunity induced by perception of TAL effectors.

  Ayaka Yoshihisa; Satomi Yoshimura; Motoki Shimizu; Sayaka Sato; Shogo Matsuno; Akira Mine; Koji Yamaguchi; Tsutomu Kawasaki

  The New phytologist 2022/09 

  Plant nucleotide-binding leucine-rich repeat receptors (NLRs) initiate immune responses by recognizing pathogen effectors. The rice gene Xa1 encodes an NLR with an N-terminal BED domain, and recognizes transcription activator-like (TAL) effectors of Xanthomonas oryzae pv. oryzae (Xoo). Our goal is to elucidate the molecular mechanisms controlling the induction of immunity by Xa1. We used yeast two-hybrid assays to screen for host factors that interact with Xa1 and identified the AP2/ERF-type transcription factor OsERF101/OsRAP2.6. Molecular complementation assays were used to confirm the interactions among Xa1, OsERF101, and two TAL effectors. We created OsERF101-overexpressing and knockout mutant lines in rice and identified genes differentially regulated in these lines, many of which are predicted to be involved in regulation of response to stimulus. Xa1 interacts in the nucleus with the TAL effectors and OsERF101 via the BED domain. Unexpectedly, both the overexpression and knockout lines of OsERF101 displayed Xa1-dependent, enhanced resistance to an incompatible Xoo strain. Different sets of genes were up- or down-regulated in the overexpression and knockout lines. Our results indicate that OsERF101 regulates the recognition of TAL effectors by Xa1, and functions as a positive regulator of Xa1-mediated immunity. Further, an additional Xa1-mediated immune pathway is negatively regulated by OsERF101.
• Cooperative regulation of PBI1 and MAPKs controls WRKY45 transcription factor in rice immunity.

  Kota Ichimaru; Koji Yamaguchi; Kenichi Harada; Yusaku Nishio; Momoka Hori; Kazuya Ishikawa; Haruhiko Inoue; Shusuke Shigeta; Kento Inoue; Keita Shimada; Satomi Yoshimura; Takumi Takeda; Eiki Yamashita; Toshimichi Fujiwara; Atsushi Nakagawa; Chojiro Kojima; Tsutomu Kawasaki

  Nature communications 13 (1) 2397 - 2397 2022/05 

  The U-box type ubiquitin ligase PUB44 positively regulates pattern-triggered immunity in rice. Here, we identify PBI1, a protein that interacts with PUB44. Crystal structure analysis indicates that PBI1 forms a four-helix bundle structure. PBI1 also interacts with WRKY45, a master transcriptional activator of rice immunity, and negatively regulates its activity. PBI1 is degraded upon perception of chitin, and this is suppressed by silencing of PUB44 or expression of XopP, indicating that PBI1 degradation depends on PUB44. These data suggest that PBI1 suppresses WRKY45 activity when cells are in an unelicited state, and during chitin signaling, PUB44-mediated degradation of PBI1 leads to activation of WRKY45. In addition, chitin-induced MAP kinase activation is required for WRKY45 activation and PBI1 degradation. These results demonstrate that chitin-induced activation of WRKY45 is regulated by the cooperation between MAP kinase-mediated phosphorylation and PUB44-mediated PBI1 degradation.
• Identification of TAL and iTAL effectors in Japanese strain T7133 of Xanthomonas oryzae pv. oryzae

  Ayaka Yoshihisa; Satomi Yoshimura; Motoki Shimizu; Koji Yamaguchi; Tsutomu Kawasaki

  JOURNAL OF GENERAL PLANT PATHOLOGY SPRINGER JAPAN KK 87 (6) 354 - 360 1345-2630 2021/11 

  Xanthomonas oryzae pv. oryzae (Xoo) possesses transcription activator-like (TAL) effectors, which are important virulence factors for bacterial blight disease. Rice nucleotide-binding leucine rich repeats receptor Xa1 recognizes TAL effectors, then induces various immune responses. To overcome host defenses, Xoo has developed TAL effector variants, termed interfering TAL (iTAL) (or truncated TAL) effectors. Japanese Xoo strain T7133 overcomes Xa1-mediated immunity. In this study, we determined the whole genome sequence of Xoo T7133 and identified TAL and iTAL effectors, revealing commonalities and differences in the TAL effectors between Xoo T7133 and avirulent strain T7174. In addition, Xoo T7133 has a different type of iTAL effector from Xoo T7174, suggesting that the iTAL effector of Xoo T7133 may contribute to the suppression of Xa1-mediated immunity.
• Pathogen- and plant-derived peptides trigger plant immunity.

  Koji Yamaguchi; Tsutomu Kawasaki

  Peptides 144 170611 - 170611 2021/07 

  Plants are constantly exposed to pathogens in their immediate environment. Plants sense the invasion of pathogens by recognizing the components including peptide fragments derived from pathogens, known as pathogen-associated molecular patterns (PAMPs). Plants also produce immunogenic peptides called phytocytokines that regulate immune responses. These molecules are recognized by pattern recognition receptors (PRRs) at plasma membrane. Activated PRRs induce a variety of immune responses including production of reactive oxygen species (ROS), induction of Ca2+ influx and activation of mitogen activated protein kinases (MAPKs). Pattern-triggered immunity (PTI) wards off microbes and pests. In this review, we summarize recent our advances in understanding how the peptide fragments are generated and perceived by plant PRRs at cell surface, and the activated PRRs transduce the downstream immune signaling.
• Novel assays to monitor gene expression and protein-protein interactions in rice using the bioluminescent protein, NanoLuc.

  Ken-Ichiro Taoka; Zenpei Shimatani; Koji Yamaguchi; Mana Ogawa; Hiromi Saitoh; Yoichi Ikeda; Hiroko Akashi; Rie Terada; Tsutomu Kawasaki; Hiroyuki Tsuji

  Plant biotechnology (Tokyo, Japan) 38 (1) 89 - 99 2021/03 

  Luciferases have been widely utilized as sensitive reporters to monitor gene expression and protein-protein interactions. Compared to firefly luciferase (Fluc), a recently developed luciferase, Nanoluciferase (NanoLuc or Nluc), has several superior properties such as a smaller size and stronger luminescence activity. We compared the reporter properties of Nluc and Fluc in rice (Oryza sativa). In both plant-based two-hybrid and split luc complementation (SLC) assays, Nluc activity was detected with higher sensitivity and specificity than that with Fluc. To apply Nluc to research involving the photoperiodic regulation of flowering, we made a knock-in rice plant in which the Nluc coding region was inserted in-frame with the OsMADS15 gene, a target of the rice florigen Hd3a. Strong Nluc activity in response to Hd3a, and in response to change in day length, was detected in rice protoplasts and in a single shoot apical meristem, respectively. Our results indicate that Nluc assay systems will be powerful tools to monitor gene expression and protein-protein interaction in plant research.
• PRR Cross-Talk Jump Starts Plant Immunity.

  Tsutomu Kawasaki

  Cell host & microbe 26 (6) 707 - 709 2019/12 

  Plants remember information related to previous pathogen infection as immunological memory, leading to a primed state of enhanced immune responses. In this issue of Cell Host & Microbe, Gong et al. (2019) discover that immune priming is established through crosstalk between cell-surface co-receptors upon MAMP perception.
• Apple immunity: unidirectional ubiquitination between two ubiquitin E3 ligases regulates the immune response in apple fruits.

  Kawasaki T

  Plant & cell physiology 0032-0781 2019/08 [Refereed]
  
• OsDRE2 contributes to chitin-triggered response through its interaction with OsRLCK185.

  Yamaguchi K; Yoshimura Y; Nakagawa S; Mezaki H; Yoshimura S; Kawasaki T

  Bioscience, biotechnology, and biochemistry 83 (2) 281 - 290 0916-8451 2019/02 [Refereed]
  
• In vivo monitoring of plant small GTPase activation using a Förster resonance energy transfer biosensor.

  Wong HL; Akamatsu A; Wang Q; Higuchi M; Matsuda T; Okuda J; Kosami KI; Inada N; Kawasaki T; Kaneko-Kawano T; Nagawa S; Tan L; Kawano Y; Shimamoto K

  Plant methods Springer Science and Business Media LLC 14 (1) 56  2018 [Refereed]
  
• Arabidopsis ubiquitin ligase PUB12 interacts with and negatively regulates Chitin Elicitor Receptor Kinase 1 (CERK1)

  Koji Yamaguchi; Hirohisa Mezaki; Masayuki Fujiwara; Yuki Hara; Tsutomu Kawasaki

  PLOS ONE PUBLIC LIBRARY SCIENCE 12 (11) e0188886  1932-6203 2017/11 [Refereed]
   

  In Arabidopsis, fungal chitin is recognized as a pathogen-associated molecular pattern (PAMP) by the chitin receptor complex containing the lysin-motif (LysM) receptor-like kinases CERK1 and LYK5. Upon the perception of chitin, CERK1 phosphorylates the receptor- like cytoplasmic kinase, PBL27, which activates the intracellular mitogen-activated protein kinase (MAPK) cascade. However, the mechanisms by which the CERK1-PBL27 complex is regulated remain largely unknown. We identified ubiquitin ligase PUB12 as a component of the PBL27 complex using co-immunoprecipitation and mass spectrometry. However, PUB12 did not interact directly with PBL27. Instead, the ARM domains of PUB12 and its paralog PUB13 interacted with the intracellular domain of CERK1 in a manner that was dependent on its autophosphorylation, suggesting that the phosphorylation-based auto-activation of CERK1 may be required for its interaction with PUB12. The co-expression of PUB12 in Nicotiana benthamiana reduced the accumulation of CERK1. The pub12 pub13 mutant exhibited enhanced chitin-induced immune responses such as ROS production, MAPK activation, and callose deposition. These results suggest that PUB12 and PUB13 are involved in the negative regulation of the chitin receptor complex, which may contribute to the transient desensitization of chitin-induced responses.
• Chitin receptor-mediated activation of MAP kinases and ROS production in rice and Arabidopsis

  Tsutomu Kawasaki; Kenta Yamada; Satomi Yoshimura; Koji Yamaguchi

  Plant Signaling and Behavior Taylor and Francis Inc. 12 (9) e1361076  1559-2324 2017/09 [Refereed]
   

  Rapid induction of plant immune responses is essential to inhibit colonization and invasion by pathogens. Plants can recognize pathogen-associated molecular patterns (PAMPs) including fungal chitin and bacterial flagellin using pattern-recognition receptors (PRRs), which trigger the intracellular activation of mitogen-activated protein kinase (MAPK) cascades and the production of reactive oxygen species (ROS). MAPK activation and ROS production play pivotal roles in the induction of robust immune responses. Recent investigation of chitin- and flagellin-induced immune signaling revealed that receptor-like cytoplasmic kinases (RLCKs) connect PRR-mediated pathogen recognition to MAPK activation and ROS production. In addition, although the MAPK cascade is mediated by 3 sequentially activated protein kinases, MAPK kinase kinase (MAPKKK), MAPK kinase (MAPKK), and MAPK, how MAPKKKs are activated downstream of PRRs in plants has not been identified until recently. In this review, we summarize recent findings of RLCK-mediated MAPK activation and ROS production in rice and Arabidopsis.
• Conservation of Chitin-Induced MAPK Signaling Pathways in Rice and Arabidopsis

  Kenta Yamada; Koji Yamaguchi; Satomi Yoshimura; Akira Terauchi; Tsutomu Kawasaki

  PLANT AND CELL PHYSIOLOGY OXFORD UNIV PRESS 58 (6) 993 - 1002 0032-0781 2017/06 [Refereed]
   

  Perception of microbe-associated molecular patterns (MAMPs) including chitin by pattern recognition receptors (PRRs) rapidly induces activation of mitogen-activated protein kinase (MAPK) cascades. However, how PRRs transmit immune signals to the MAPK cascade is largely unknown. Recently, Arabidopsis receptor-like cytoplasmic kinase PBL27 has been reported to activate MAPKs through phosphorylation of AtMAPKKK5 in the chitin signaling pathway. In this study, we found that OsRLCK185, a rice ortholog of PBL27, regulates chitin-induced MAPK activation in a similar fashion to PBL27 in rice. Upon chitin perception, OsRLCK185 is phosphorylated by OsCERK1, a component of the chitin receptor complex. OsRLCK185 interacted with OsMAPKKK11 and OsMAPKKK18, rice orthologs of AtMAPKKK5, in yeast two-hybrid assays. Silencing of both OsMAPKKK11 and OsMAPKKK18 significantly reduced chitin-induced activation of OsMPK3 and OsMPK6. Expression levels of OsMAPKKK18 were much higher than that of OsMAPKKK11 in rice cells, which was consistent with the fact that the Osmapkkk11 single mutation did not affect MAPK activation. This result suggested that OsMAPKKK18 plays a more important role than OsMAPKKK11 in the chitin-induced activation of OsMPK3 and OsMPK6. The bimolecular fluorescence complementation (BiFC) experiment indicated that OsRLCK185 interacted with OsMAPKKK18 at the plasma membrane in planta. In vitro phosphorylation experiments showed that OsRLCK185 directly phosphorylates OsMAPKKK18. Furthermore, OsMAPKKK18 interacted with the MAPKK OsMKK4, the upstream component of OsMPK3/6. These results suggested that OsRLCK185 connects the chitin receptor to the MAPK cascade consisting of OsMAPKKK18-OsMKK4-OsMPK3/6. Our data revealed that chitin-induced MAPK activation in rice and Arabidopsis is regulated by common homologous elements.
• Chitin-triggered MAPK activation and ROS generation in rice suspension-cultured cells

  Koji Yamaguchi; Tsutomu Kawasaki

  Methods in Molecular Biology Humana Press Inc. 1578 309 - 316 1064-3745 2017 [Refereed]
   

  Suspension-cultured cells respond sensitively to a number of stimuli including pathogen-derived molecules. Therefore, they are used in a simple, single-cell model system in order to gain insights into immune signaling pathways in rice. Here we describe protocols for studying chitin-induced MAPK activation and ROS generation in rice suspension-cultured cells.
• The Arabidopsis CERK1-associated kinase PBL27 connects chitin perception to MAPK activation

  Kenta Yamada; Koji Yamaguchi; Tomomi Shirakawa; Hirofumi Nakagami; Akira Mine; Kazuya Ishikawa; Masayuki Fujiwara; Mari Narusaka; Yoshihiro Narusaka; Kazuya Ichimura; Yuka Kobayashi; Hidenori Matsui; Yuko Nomura; Mika Nomoto; Yasuomi Tada; Yoichiro Fukao; Tamo Fukamizo; Kenichi Tsuda; Ken Shirasu; Naoto Shibuya; Tsutomu Kawasaki

  EMBO JOURNAL WILEY-BLACKWELL 35 (22) 2468 - 2483 0261-4189 2016/11 [Refereed]
   

  Perception of microbe-associated molecular patterns by host cell surface pattern recognition receptors (PRRs) triggers the intracellular activation of mitogen-activated protein kinase (MAPK) cascades. However, it is not known how PRRs transmit immune signals to MAPK cascades in plants. Here, we identify a complete phospho-signaling transduction pathway from PRR-mediated pathogen recognition to MAPK activation in plants. We found that the receptor-like cytoplasmic kinase PBL27 connects the chitin receptor complex CERK1-LYK5 and a MAPK cascade. PBL27 interacts with both CERK1 and the MAPK kinase kinase MAPKKK5 at the plasma membrane. Knockout mutants of MAPKKK5 compromise chitin-induced MAPK activation and disease resistance to Alternaria brassicicola. PBL27 phosphorylates MAPKKK5 invitro, which is enhanced by phosphorylation of PBL27 by CERK1. The chitin perception induces disassociation between PBL27 and MAPKKK5 invivo. Furthermore, genetic evidence suggests that phosphorylation of MAPKKK5 by PBL27 is essential for chitin-induced MAPK activation in plants. These data indicate that PBL27 is the MAPKKK kinase that provides the missing link between the cell surface chitin receptor and the intracellular MAPK cascade in plants.
• Plant-specific DUF1110 protein from Oryza sativa: expression, purification and crystallization

  Kenichi Harada; Eiki Yamashita; Kento Inoue; Koji Yamaguchi; Toshimichi Fujiwara; Atsushi Nakagawa; Tsutomu Kawasaki; Chojiro Kojima

  ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS INT UNION CRYSTALLOGRAPHY 72 (Pt 6) 480 - 484 2053-230X 2016/06 [Refereed]
   

  The Os01T0156300 protein from Oryza sativa has been classified into the domain of unknown function (DUF) family DUF1110. DUF1110 family members exist in monocotyledons but not in dicotyledons, and share no sequence identity with proteins for which structures have been reported. In this study, the Os01T0156300 protein was crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 1.84 angstrom resolution. The crystal belonged to space group P2(1), with unit-cell parameters a = 89.9, b = 89.8, c = 107.1 angstrom, beta = 106.6 degrees. The asymmetric unit was estimated to contain 6-11 molecules.
• Bacterial effector modulation of host E3 ligase activity suppresses PAMP-triggered immunity in rice

  Kazuya Ishikawa; Koji Yamaguchi; Kazuaki Sakamoto; Satomi Yoshimura; Kento Inoue; Seiji Tsuge; Chojiro Kojima; Tsutomu Kawasaki

  NATURE COMMUNICATIONS NATURE PUBLISHING GROUP 5 (5430) 5430  2041-1723 2014/11 [Refereed]
   

  Pathogen effector proteins are delivered to host cells to suppress plant immunity. However, the mechanisms by which effector proteins function are largely unknown. Here we show that expression of XopP(Xoo), an effector of rice pathogen Xanthomonas oryzae pv. oryzae, in rice strongly suppresses peptidoglycan (PGN)- and chitin-triggered immunity and resistance to X. oryzae. XopP(Xoo) targets OsPUB44, a rice ubiquitin E3 ligase with a unique U-box domain. We find that XopP(Xoo) directly interacts with the OsPUB44 U-box domain and inhibits ligase activity. Two amino-acid residues specific for the OsPUB44 U-box domain are identified, which are responsible for the interaction with XopP(Xoo). Silencing of OsPUB44 suppresses PGN- and chitin-triggered immunity and X. oryzae resistance, indicating that OsPUB44 positively regulates immune responses. Thus, it is likely that Xop(PXoo) suppresses immune responses by directly interacting with and inhibiting a positive regulator of plant immunity.
• The Crystal Structure of the Plant Small GTPase OsRac1 Reveals Its Mode of Binding to NADPH Oxidase

  Ken-ichi Kosami; Izuru Ohki; Minoru Nagano; Kyoko Furuita; Toshihiko Sugiki; Yoji Kawano; Tsutomu Kawasaki; Toshimichi Fujiwara; Atsushi Nakagawa; Ko Shimamoto; Chojiro Kojima

  JOURNAL OF BIOLOGICAL CHEMISTRY AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 289 (41) 28569 - 28578 0021-9258 2014/10 [Refereed]
   

  Rac/Rop proteins are Rho-type small GTPases that act as molecular switches in plants. Recent studies have identified these proteins as key components in many major plant signaling pathways, such as innate immunity, pollen tube growth, and root hair formation. In rice, the Rac/Rop protein OsRac1 plays an important role in regulating the production of reactive oxygen species (ROS) by the NADPH oxidase OsRbohB during innate immunity. However, the molecular mechanism by which OsRac1 regulates OsRbohB remains unknown. Here, we report the crystal structure of OsRac1 complexed with the non-hydrolyzable GTP analog guanosine 5'-(beta,gamma-imido) triphosphate at 1.9 angstrom resolution; this represents the first active-form structure of a plant small GTPase. To elucidate the ROS production in rice cells, structural information was used to design OsRac1 mutants that displayed reduced binding to OsRbohB. Only mutations in the OsRac1 Switch I region showed attenuated interactions with OsRbohB in vitro. In particular, Tyr(39) and Asp(45) substitutions suppressed ROS production in rice cells, indicating that these residues are critical for interaction with and activation of OsRbohB. Structural comparison of active-form OsRac1 with AtRop9 in its GDP-bound inactive form showed a large conformational difference in the vicinity of these residues. Our results provide new insights into the molecular mechanism of the immune response through OsRac1 and the various cellular responses associated with plant Rac/Rop proteins.
• Selective regulation of the chitin-induced defense response by the Arabidopsis receptor-like cytoplasmic kinase PBL27

  Tomonori Shinya; Koji Yamaguchi; Yoshitake Desaki; Kenta Yamada; Tomoko Narisawa; Yoshihiro Kobayashi; Kanako Maeda; Maruya Suzuki; Takumi Tanimoto; Jun Takeda; Masato Nakashima; Ryota Funama; Mari Narusaka; Yoshihiro Narusaka; Hanae Kaku; Tsutomu Kawasaki; Naoto Shibuya

  PLANT JOURNAL WILEY-BLACKWELL 79 (1) 56 - 66 0960-7412 2014/07 [Refereed]
   

  Recognition of microbe-associated molecular patterns (MAMPs) initiates pattern-triggered immunity in host plants. Pattern recognition receptors (PRRs) and receptor-like cytoplasmic kinases (RLCKs) are the major components required for sensing and transduction of these molecular patterns. However, the regulation of RLCKs by PRRs and their specificity remain obscure. In this study we show that PBL27, an Arabidopsis ortholog of OsRLCK185, is an immediate downstream component of the chitin receptor CERK1 and contributes to the regulation of chitin-induced immunity in Arabidopsis. Knockout of PBL27 resulted in the suppression of several chitin-induced defense responses, including the activation of MPK3/6 and callose deposition as well as in disease resistance against fungal and bacterial infections. On the other hand, the contribution of PBL27 to flg22 signaling appears to be very limited, suggesting that PBL27 selectively regulates defense signaling downstream of specific PRR complexes. In vitro phosphorylation experiments showed that CERK1 preferentially phosphorylated PBL27 in comparison to BIK1, whereas phosphorylation of PBL27 by BAK1 was very low compared with that of BIK1. Thus, the substrate specificity of the signaling receptor-like kinases, CERK1 and BAK1, may determine the preference of downstream RLCKs.
• Purification, crystallization and preliminary X-ray crystallographic analysis of a rice Rac/Rop GTPase, OsRac1

  Ken-ichi Kosami; Izuru Ohki; Kokoro Hayashi; Ryo Tabata; Sayaka Usugi; Tsutomu Kawasaki; Toshimichi Fujiwara; Atsushi Nakagawa; Ko Shimamoto; Chojiro Kojima

  ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY AND CRYSTALLIZATION COMMUNICATIONS WILEY-BLACKWELL 70 (Pt 1) 113 - 115 1744-3091 2014/01 [Refereed]
   

  Small GTPases regulate a large variety of key cellular processes. Plant small Rac/Rop GTPases have recently received broad attention as it is becoming clear that these enzymes regulate various plant cellular processes. OsRac1, a rice Rac/Rop protein, is a key regulator of reactive oxygen species (ROS) production and induces immune responses. Although four structures of plant small GTPases have been reported, all of these were of the inactive form. Here, OsRac1 was purified and co-crystallized with the GTP analogue 50-guanylyl imidodiphosphate (GMPPNP). The crystal belonged to space group P2(1)2(1)2(1) and a complete data set was collected to 1.9 angstrom resolution.
• Purification, crystallization and preliminary X-ray crystallographic analysis of a rice Rac/Rop GTPase, OsRac1

  Ken-Ichi Kosami; Izuru Ohki; Kokoro Hayashi; Ryo Tabata; Sayaka Usugi; Tsutomu Kawasaki; Toshimichi Fujiwara; Atsushi Nakagawa; Ko Shimamoto; Chojiro Kojima

  Acta Crystallographica Section F:Structural Biology Communications International Union of Crystallography 70 (1) 113 - 115 2053-230X 2014 [Refereed]
   

  Small GTPases regulate a large variety of key cellular processes. Plant small Rac/Rop GTPases have recently received broad attention as it is becoming clear that these enzymes regulate various plant cellular processes. OsRac1, a rice Rac/Rop protein, is a key regulator of reactive oxygen species (ROS) production and induces immune responses. Although four structures of plant small GTPases have been reported, all of these were of the inactive form. Here, OsRac1 was purified and co-crystallized with the GTP analogue 5′-guanylyl imidodiphosphate (GMPPNP). The crystal belonged to space group P2 12121 and a complete data set was collected to 1.9 Å resolution. © 2014 International Union of Crystallography. All rights reserved.
• Xanthomonas エフェクターによる宿主のユビキチン修飾系の制御

  石川 和也; 井上 健太; 山口 公志; 川﨑 努

  植物細菌病談話会論文集 26 94 - 101 2014 [Refereed]
  
• Suppression of Rice Immunity by Xanthomonas oryzae Type III Effector Xoo2875

  Koji Yamaguchi; Yusuke Nakamura; Kazuya Ishikawa; Yuya Yoshimura; Seiji Tsuge; Tsutomu Kawasaki

  BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY TAYLOR & FRANCIS LTD 77 (4) 796 - 801 0916-8451 2013/04 [Refereed]
   

  Xanthomonas oryzae delivers effector proteins into host cells through a type III secretion system to inhibit host immune responses, but how these effectors suppress host immunity is largely unknown. Here we found that Xoo2875, one of the effectors of X. oryzae, strongly inhibited host resistance to X. oryzae. Transgenic rice plants expressing Xoo2875 exhibited semi-dwarfism and a reduction in Brassinolide-dependent laminar inclination, characteristics of brassinosteroid (BR)-insensitive mutants caused by mutations of the BR receptor. A yeast two-hybrid experiment indicated that Xoo2875 interacted with OsBAK1, an essential component of both microbe-associated molecular patterns (MAMPs) and BR receptors, suggesting that the virulent activity of Xoo2875 is mediated by inhibition of OsBAK1. Expression of Xoo2875 in Arabidopsis cells activated host immune responses, suggesting the presence of intracellular immune receptors that recognize Xoo2875. Because Xoo2875 homologs are highly conserved in Xanthomonas species, the development of Xoo2875-induced immunity is probably a useful strategy to avoid pathogen invasion.
• An OsCEBiP/OsCERK1-OsRacGEF1-OsRac1 Module Is an Essential Early Component of Chitin-Induced Rice Immunity

  Akira Akamatsu; Hann Lin Wong; Masayuki Fujiwara; Jun Okuda; Keita Nishide; Kazumi Uno; Keiko Imai; Kenji Umemura; Tsutomu Kawasaki; Yoji Kawano; Ko Shimamoto

  CELL HOST & MICROBE CELL PRESS 13 (4) 465 - 476 1931-3128 2013/04 [Refereed]
   

  OsCEBiP, a chitin-binding protein, and OsCERK1, a receptor-like kinase, are plasma membrane (PM) proteins that form a receptor complex essential for fungal chitin-driven immune responses in rice. The signaling events immediately following chitin perception are unclear. Investigating the spatiotemporal regulation of the rice small GTPase OsRac1, we find that chitin induces rapid activation of OsRac1 at the PM. Searching for OsRac1 interactors, we identified OsRacGEF1 as a guanine nucleotide exchange factor for OsRac1. OsRacGEF1 interacts with OsCERK1 and is activated when its C-terminal S549 is phosphorylated by the cytoplasmic domain of OsCERK1 in response to chitin. Activated OsRacGEF1 is required for chitin-driven immune responses and resistance to rice blast fungus infection. Further, a protein complex including OsCERK1 and OsRacGEF1 is transported from the endoplasmic reticulum to the PM. Collectively, our results suggest that OsCEBiP, OsCERK1, OsRacGEF1, and OsRac1 function as key components of a "defensome" critically engaged early during chitin-induced immunity.
• A Receptor-like Cytoplasmic Kinase Targeted by a Plant Pathogen Effector Is Directly Phosphorylated by the Chitin Receptor and Mediates Rice Immunity

  Koji Yamaguchi; Kenta Yamada; Kazuya Ishikawa; Satomi Yoshimura; Nagao Hayashi; Kouhei Uchihashi; Nobuaki Ishihama; Mitsuko Kishi-Kaboshi; Akira Takahashi; Seiji Tsuge; Hirokazu Ochiai; Yasuomi Tada; Ko Shimamoto; Hirofumi Yoshioka; Tsutomu Kawasaki

  CELL HOST & MICROBE CELL PRESS 13 (3) 347 - 357 1931-3128 2013/03 [Refereed]
   

  CERK1 is a lysine motif-containing plant pattern recognition receptor for chitin and peptidoglycan. Chitin recognition by OsCERK1 triggers rapid engagement of a rice MAP kinase cascade, which leads to defense response activation. How the MAP kinase cascades are engaged downstream of OsCERK1 remains obscure. Searching for host proteins that interact with Xoo1488, an effector of the rice pathogen Xanthomonas oryzae, we identified the rice receptor-like cytoplasmic kinase, OsRLCK185. Silencing OsRLCK185 suppressed peptidoglycan-and chitin-induced immune responses, including MAP kinase activation and defense-gene expression. In response to chitin, OsRLCK185 associates with, and is directly phosphorylated by, OsCERK1 at the plasma membrane. Xoo1488 inhibits peptidoglycan-and chitin-induced immunity and pathogen resistance. Additionally, OsCERK1-mediated phosphorylation of OsRLCK185 is suppressed by Xoo1488, resulting in the inhibition of chitin-induced MAP kinase activation. These data support a role for OsRLCK185 as an essential immediate downstream signaling partner of OsCERK1 in mediating chitin-and peptidoglycan-induced plant immunity.
• Receptor-like cytoplasmic kinases are pivotal components in pattern recognition receptor-mediated signaling in plant immunity

  Koji Yamaguchi; Kenta Yamada; Tsutomu Kawasaki

  Plant Signaling and Behavior Landes Bioscience 8 (10) doi: 10.4161/psb.25662  1559-2324 2013 [Refereed]
   

  Innate immunity is generally initiated with recognition of conserved pathogen-associated molecular patterns (PAMPs). PAMPs are perceived by pattern recognition receptors (PRRs), leading to activation of a series of immune responses, including the expression of defense genes, ROS production and activation of MAP kinase. Recent progress has indicated that receptor-like cytoplasmic kinases (RLCKs) are directly activated by ligand-activated PRRs and initiate pattern -triggered immunity (PTi) in both Arabidopsis and rice. To suppress PTi, pathogens inhibit the RLCKs by many types of efectors, including AvrAC, AvrPphB and Xoo1488. in this review, we summarize recent advances in RLCK-mediated PTi in plants. © 2013 Landes Bioscience.
• OsRap2.6 transcription factor contributes to rice innate immunity through its interaction with Receptor for Activated Kinase-C 1 (RACK1)

  Mwathi Jane Wamaitha; Risa Yamamoto; Hann Ling Wong; Tsutomu Kawasaki; Yoji Kawano; Ko Shimamoto

  RICE SPRINGER 5 35  1939-8425 2012/12 [Refereed]
   

  Background: The rice small GTPase OsRac1 is a molecular switch in rice innate immunity. The Receptor for Activated Kinase C-1 (RACK1) interacts with OsRac1 to suppress the growth of the rice blast fungus, Magnaporthe oryzae. RACK1 has two homologs in rice, RACK1A and RACK1B. Overexpressing RACK1A enhances resistance to the rice blast fungus. However, RACK1A downstream signals are largely unknown. Results: Here, we report the identification of OsRap2.6, a transcription factor that interacts with RACK1A. We found a 94% similarity between the OsRap2.6 AP2 domain and Arabidopsis Rap2.6 (AtRap2.6). Bimolecular fluorescence complementation (BiFC) assays in rice protoplasts using tagged OsRap2.6 and RACK1A with the C-terminal and N-terminal fragments of Venus (Vc/Vn) indicated that OsRap2.6 and RACK1A interacted and localized in the nucleus and the cytoplasm. Moreover, OsRap2.6 and OsMAPK3/6 interacted in the nucleus and the cytoplasm. Expression of defense genes PAL1 and PBZ1 as well as OsRap2.6 was induced after chitin treatment. Disease resistance analysis using OsRap2.6 RNAi and overexpressing (Ox) plants infected with the rice blast fungus indicated that OsRap2.6 RNAi plants were highly susceptible, whereas OsRap2.6 Ox plants had an increased resistance to the compatible blast fungus. Conclusions: OsRap2.6 contributes to rice innate immunity through its interaction with RACK1A in compatible interactions.
• SWAP70 functions as a Rac/Rop guanine nucleotide-exchange factor in rice

  Koji Yamaguchi; Keiko Imai; Akira Akamatsu; Masanori Mihashi; Nagao Hayashi; Ko Shimamoto; Tsutomu Kawasaki

  PLANT JOURNAL WILEY-BLACKWELL 70 (3) 389 - 397 0960-7412 2012/05 [Refereed]
   

  Rho family small GTPases are involved in diverse signaling processes including immunity, growth, and development. The activity of Rho GTPases is regulated by cycling between guanosine diphosphate (GDP)-bound inactive and guanosine triphosphate (GTP)-bound active forms, in which guanine nucleotide exchange factors (GEFs) predominantly function to promote activation of the GTPases. In animals, most Rho GEFs possess a Dbl (diffuse B-cell lymphoma) homology (DH) domain which functions as a GEF-catalytic domain. However, no proteins with the DH domain have been identified in plants so far. Instead, plant-specific Rho GEFs with the PRONE domain responsible for GEF activity have been found to constitute a large family in plants. In this study, we found rice homologs of human SWAP70, Oryza sativa (Os) SWAP70A and SWAP70B, containing the DH domain. OsSWAP70A interacted with rice Rho GTPase OsRac1, an important signaling factor for immune responses. The DH domain of OsSWAP70A exhibited the GEF-catalytic activity toward OsRac1 as found in animal Rho GEFs, indicating that plants have the functional DH domains. Transient expression of OsSWAP70A enhanced OsRac1-mediated production of reactive oxygen species in planta. Reduction of OsSWAP70A and OsSWAP70B mRNA levels by RNA interference resulted in the suppression of chitin elicitor-induced defense gene expression and ROS production. Thus, it is likely that OsSWAP70 regulates immune responses through activation of OsRac1.
• The bHLH Rac Immunity1 (RAI1) Is Activated by OsRac1 via OsMAPK3 and OsMAPK6 in Rice Immunity

  Sung-Hyun Kim; Tetsuo Oikawa; Junko Kyozuka; Hann Ling Wong; Kenji Umemura; Mitsuko Kishi-Kaboshi; Akira Takahashi; Yoji Kawano; Tsutomu Kawasaki; Ko Shimamoto

  PLANT AND CELL PHYSIOLOGY OXFORD UNIV PRESS 53 (4) 740 - 754 0032-0781 2012/04 [Refereed]
   

  The Rac/Rop GTPase OsRac1 plays an essential role in rice immunity. However, the regulatory genes acting downstream of OsRac1 are largely unknown. We focused on the RAI1 gene, which is up-regulated in suspension cells expressing a constitutively active form of OsRac1. RAI1 encodes a putative basic helix-loop-helix transcription factor. A microarray analysis of cells transformed with an inducible RAI1 construct showed increased expression of PAL1 and OsWRKY19 genes after induction, suggesting that these genes are regulated by RAI1. This was confirmed using RAI1 T-DNA activation-tagged and RNA interference lines. The PAL1 and OsWRKY19 genes were also up-regulated by sphingolipid and chitin elicitors, and the RAI1 activation-tagged plants had increased resistance to a rice blast fungus. These results indicated that RAI1 is involved in defense responses in rice. RAI1 interacted with OsMAPK3 and OsMAPK6 proteins in vivo and in vitro. Also, RAI1 was phosphorylated by OsMAPK3/6 and OsMKK4-dd in vitro. Overexpression of OsMAPK6 and/or OsMAPK3 together with OsMKK4-dd increased PAL1 and OsWRKY19 expression in rice protoplasts. Therefore, the regulation of PAL1 and OsWRKY19 expression by RAI1 could be controlled via an OsMKK4-OsMAPK3/6 cascade. Co-immunoprecipitation assays indicated that OsMAPK3 and OsRac1 occur in the same complex as OsMAPK6. Taken together, our results indicate that RAI1 could be regulated by OsRac1 through an OsMAPK3/6 cascade. In this study, we have identified RAI1 as the first transcription factor acting downstream of OsRac1. This work will help us to understand the immune system regulated by OsRac1 in rice and its orthologs in other plant species.
• Function of Arabidopsis SWAP70 GEF in immune response

  Koji Yamaguchi; Tsutomu Kawasaki

  Plant Signaling and Behavior 4 7 (4) 465 - 468 1559-2316 2012/04 [Refereed]
   

  In animals, major classes of Rho guanine nucleotide exchange factors (GEFs) possess a Dbl (diffuse B-cell lymphoma)- homology (DH) domain that functions as a GEF-catalytic domain. However, no GEFs with the DH domain had been identified in plants. Recently, we found that the rice homolog of human SWAP70, Oryza sative (Os) SWAP70, containing the DH domain, exhibited GEF activity toward the rice Rho GTPase OsRac1, and regulates chitin-induced production of reactive oxygen species and defense gene expression in rice.1 Arabidopsis contains a single SWAP70 gene. A T-DNA insertion mutant of Arabidopsis SWAP70 was morphologically wild type. Measurement of in planta growth of Pseudomonas syringae DC3000 hrcC, a mutant incapable of type III effector delivery, revealed enhanced growth of the pathogen in the atswap70 mutant, indicating that AtSWAP70 is required for PAMP-triggered immunity. In addition, the atswap70 mutation reduced the RPM1-mediated hypersensitive response. These results suggested that AtSWAP70 plays a role in both PAMP-and effector-triggered immunity in Arabidopsis. © Landes Bioscience.
• Activation of a Rac GTPase by the NLR Family Disease Resistance Protein Pit Plays a Critical Role in Rice Innate Immunity

  Yoji Kawano; Akira Akamatsu; Keiko Hayashi; Yusuke Housen; Jun Okuda; Ai Yao; Ayako Nakashima; Hiroki Takahashi; Hitoshi Yoshida; Hann Ling Wong; Tsutomu Kawasaki; Ko Shimamoto

  CELL HOST & MICROBE CELL PRESS 7 (5) 362 - 375 1931-3128 2010/05 [Refereed]
   

  The nucleotide-binding domain and leucine-rich repeat-containing (NLR) family proteins recognize pathogen-derived molecules and trigger immune responses in both plants and animals. In plants, the direct or indirect recognition of specific pathogen effectors by NLRs culminates in a hypersensitive response (HR) and the production of reactive oxygen species (ROS), key components of the plant defense response. However, the molecules activated by NLRs and how they induce immune responses are largely unknown. We found that the rice GTPase Os-Rac1 at the plasma membrane interacts directly with Pit, an NLR protein that confers resistance to the rice blast fungus. OsRac1 contributes to Pit-mediated ROS production as well as the HR and is required for Pit-mediated disease resistance in rice. Furthermore, the active form of Pit induces the activation of OsRac1 at the plasma membrane. Thus, OsRac1 is activated by Pit during pathogen attack and plays a critical role in Pit-mediated immunity in rice.
• Sekiguchi Lesion Gene Encodes a Cytochrome P450 Monooxygenase That Catalyzes Conversion of Tryptamine to Serotonin in Rice

  Tadashi Fujiwara; Sylvie Maisonneuve; Masayuki Isshiki; Masaharu Mizutani; Letian Chen; Hann Ling Wong; Tsutomu Kawasaki; Ko Shimamoto

  JOURNAL OF BIOLOGICAL CHEMISTRY AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 285 (15) 11308 - 11313 0021-9258 2010/04 [Refereed]
   

  Serotonin is a well known neurotransmitter in mammals and plays an important role in various mental functions in humans. In plants, the serotonin biosynthesis pathway and its function are not well understood. The rice sekiguchi lesion (sl) mutants accumulate tryptamine, a candidate substrate for serotonin biosynthesis. We isolated the SL gene by map-based cloning and found that it encodes CYP71P1 in a cytochrome P450 monooxygenase family. A recombinant SL protein exhibited tryptamine 5-hydroxylase enzyme activity and catalyzed the conversion of tryptamine to serotonin. This pathway is novel and has not been reported in mammals. Expression of SL was induced by the N-acetylchitooligosaccharide (chitin) elicitor and by infection with Magnaporthe grisea, a causal agent for rice blast disease. Exogenously applied serotonin induced defense gene expression and cell death in rice suspension cultures and increased resistance to rice blast infection in plants. We also found that serotonin-induced defense gene expression is mediated by the RacGTPase pathway and by the G alpha subunit of the heterotrimeric G protein. These results suggest that serotonin plays an important role in rice innate immunity.
• Analysis of the Rac/Rop Small GTPase Family in Rice: Expression, Subcellular Localization and Role in Disease Resistance

  Letian Chen; Kenji Shiotani; Takashi Togashi; Daisuke Miki; Misa Aoyama; Hann Ling Wong; Tsutomu Kawasaki; Ko Shimamoto

  PLANT AND CELL PHYSIOLOGY OXFORD UNIV PRESS 51 (4) 585 - 595 0032-0781 2010/04 [Refereed]
   

  Plant-specific Rac/Rop small GTPases function as molecular switches for numerous signal transduction events, including defense responses. To understand the function of each of the seven Rac/Rop family members in rice, we studied the tissue-specific expression patterns of Rac/Rop genes by semi-quantitative reverse transcriptionPCR (RTPCR), and also Rac/Rop subcellular localization using green fluorescent protein (GFP) fusion proteins in transient expression systems. We also investigated the roles of these genes in disease resistance by testing single Rac/Rop-RNAi (RNA interference) plants against the rice blast pathogen Magnaporthe grisea. Our studies show that expression of OsRac2, 6 and 7 is very low in leaf blades, and reveal a strong correlation between the number of lysine and/or arginine (KR) residues in the polybasic region of Rac/Rop GTPases and their subcellular distribution invivo. Infection assays showed that OsRac1 is a positive regulator of blast resistance, confirming previous observations, whereas OsRac4 and OsRac5 are negative regulators of blast resistance. OsRac6 may make minor contributions to disease resistance, while OsRac3 and OsRac7 are probably not involved in defense. Therefore, our study suggests that the rice Rac/Rop family plays multiple roles in diverse cellular activities and has both positive and negative functions in disease resistance.
• The Hop/Sti1-Hsp90 Chaperone Complex Facilitates the Maturation and Transport of a PAMP Receptor in Rice Innate Immunity

  Letian Chen; Satoshi Hamada; Masayuki Fujiwara; Tingheng Zhu; Nguyen Phuong Thao; Hann Ling Wong; Priti Krishna; Takashi Ueda; Hanae Kaku; Naoto Shibuya; Tsutomu Kawasaki; Ko Shimamoto

  CELL HOST & MICROBE CELL PRESS 7 (3) 185 - 196 1931-3128 2010/03 [Refereed]
   

  Recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) represents a critical first step of innate defense in plants and animals. However, maturation and transport of PRRs are not well understood. We find that the rice chitin receptor OsCERK1 interacts with Hsp90 and its cochaperone Hop/Sti1 in the endoplasmic reticulum (ER). Hop/Sti1 and Hsp90 are required for efficient transport of OsCERK1 from the ER to the plasma membrane (PM) via a pathway dependent on Sari, a small GTPase which regulates ER-to-Golgi trafficking. Further, Hop/Sti1 and Hsp90 are present at the PM in a complex (designated the "defensome") with OsRac1, a plant-specific Rho-type GTPase. Finally, Hop/Sti1 was required for chitin-triggered immunity and resistance to rice blast fungus. Our results suggest that the Hop/Sti1-Hsp90 chaperone complex plays an important and likely conserved role in the maturation and transport of PRRs and may function to link PRRs and Rac/Rop GTPases.
• Structure of the N-terminal Regulatory Domain of a Plant NADPH Oxidase and Its Functional Implications

  Takashi Oda; Hiroshi Hashimoto; Naoyuki Kuwabara; Satoko Akashi; Kokoro Hayashi; Chojiro Kojima; Hann Ling Wong; Tsutomu Kawasaki; Ko Shimamoto; Mamoru Sato; Toshiyuki Shimizu

  JOURNAL OF BIOLOGICAL CHEMISTRY AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 285 (2) 1435 - 1445 0021-9258 2010/01 [Refereed]
   

  Plant NADPH oxidases (Rboh, for respiratory burst oxidase homolog) produce reactive oxygen species that are key regulators of various cellular events including plant innate immunity. Rbohs possess a highly conserved cytoplasmic N-terminal region containing two EF-hand motifs that regulate Rboh activity. Rice (Oryza sativa) RbohB (OsRbohB) is regulated by the direct binding of a small GTPase (Rac1) to this regulatory region as well as by Ca(2+) binding to the EF-hands. Here, we present the atomic structure of the N-terminal region of OsRbohB. The structure reveals that OsRbohB forms a unique dimer stabilized by swapping the EF-hand motifs. We identified two additional EF-hand-like motifs that were not predicted from sequence data so far. These EF-hand-like motifs together with the swapped EF-hands form a structure similar to that found in calcineurin B. We observed conformational changes mediated by Ca(2+) binding to only one EF-hand. Structure-based in vitro pulldown assays and NMR titration experiments defined the OsRac1 binding interface within the coiled-coil region created by swapping the EF-hands. In addition, we demonstrate a direct intramolecular interaction between the N and C terminus, and that the complete N-terminal cytoplasmic region is required for this interaction. The structural features and intramolecular interactions characterized here might be common elements shared by Rbohs that contribute to the regulation of reactive oxygen species production.
• Proteome Analysis of Detergent-Resistant Membranes (DRMs) Associated with OsRac1-Mediated Innate Immunity in Rice

  Masayuki Fujiwara; Satoshi Hamada; Minori Hiratsuka; Yoichiro Fukao; Tsutomu Kawasaki; Ko Shimamoto

  PLANT AND CELL PHYSIOLOGY OXFORD UNIV PRESS 50 (7) 1191 - 1200 0032-0781 2009/07 [Refereed]
   

  OsRac1, a member of the Rac/Rop GTPase family, plays important roles as a molecular switch in rice innate immunity, and the active form of OsRac1 functions in the plasma membrane (PM). To study the precise localization of OsRac1 in the PM and its possible association with other signaling components, we performed proteomic analysis of DRMs (detergent-resistant membranes) isolated from rice suspension-cultured cells transformed with myc-tagged constitutively active (CA) OsRac1. DRMs are regions of the PM that are insoluble after Triton X-100 treatment under cold conditions and are thought to be involved in various signaling processes in animal, yeast and plant cells. We identified 192 proteins in DRMs that included receptor-like kinases (RLKs) such as Xa21, nucleotide-binding leucine-rich repeat (NB-LRR)-type disease resistance proteins, a glycosylphosphatidylinositol (GPI)-anchored protein, syntaxin, NADPH oxidase, a WD-40 repeat family protein and various GTP-binding proteins. Many of these proteins have been previously identified in the DRMs isolated from other plant species, and animal and yeast cells, validating the methods used in our study. To examine the possible association of DRMs and OsRac1-mediated innate immunity, we used rice suspension-cultured cells transformed with myc-tagged wild-type (WT) OsRac1 and found that OsRac1 and RACK1A, an effector of OsRac1, shifted to the DRMs after chitin elicitor treatment. These results suggest that OsRac1-mediated innate immunity is associated with DRMs in the PM.
• ROP/RAC GTPases

  Ying Fu; Tsutomu Kawasaki; Ko Shimamoto; Zhenbiao Yang

  Annual Plant Reviews: Intracellular Signaling in Plants wiley 33 64 - 99 2009/02 

  Rho-family small GTPases are monomeric guanine nucleotide-binding proteins that act as key molecular switches in the regulation of many important cellular processes. ROP (Rho-related GTPase from plants)/RAC is a plant-specific subfamily of Rho GTPases that plays a versatile role in the regulation of plant growth, development, and responses to the environment. PlantROP/RACproteins share conserved structural features, cellular functions, and functional partners with their counterparts in fungi and animals. However, plant ROP/RAC GTPases contain unique structural motifs not present in their fungal and animal counterparts. Furthermore, recent studies have revealed several classes of plant-specific regulators and effector proteins for the ROP subfamily of Rho GTPases. Several ROPdependent signaling networks have also emerged from the investigation of ROPinteracting proteins. This chapter summarizes our current knowledge ofROP/RAC signaling mechanisms and pathways/networks in the two model plant systems, Arabidopsis and rice.
• Rice Guanine Nucleotide Exchange Factors for Small GTPase OsRac1 Involved in Innate Immunity of Rice

  Tsutomu Kawasaki; Keiko Imai; Hann Ling Wong; Yoji Kawano; Keita Nishide; Jun Okuda; Ko Shimamoto

  ADVANCES IN GENETICS, GENOMICS AND CONTROL OF RICE BLAST DISEASE SPRINGER 179 - + 2009 

  Small GTPase OsRac1 is a key regulator for induction of immune responses in rice. Activation of OsRac1 induces NADPH oxidase-mediated reactive oxygen species (ROS) production, PR gene expression, production of antimicrobial compounds, and lignification, which result in enhanced resistance to Magnaporthe oryzae and Xanthomonas oryzae. Inhibition of OsRac1 function suppresses the hypersensitive response induced by avirulent M. oryzae. Thus, it is likely that OsRac1 plays important roles in R protein-mediated resistance and basal resistance. However, how OsRac1 is activated during immune response remains unknown. Recently, a new type of guanine nucleotide exchange factor (GEF) for Rac/Rop GTPase has been found in plants, termed PRONE-type GEE We found eleven PRONE-type RacGEFs in rice, which may be involved in regulation of OsRac1 in innate immunity response. Recently, the PRONE-type GEF was found to interact with receptor-like protein kinase similar to R-proteins and PAMPs receptors such as Xa-21, Pi-d2, FLS2 and EFR, suggesting that the OsRacGEFs may regulate both PAMPs- and R protein-mediated disease resistance through activation of OsRac1 in rice.
• Rac GTPase and the Regulation of NADPH Oxidase in Rice Innate Immunity Response

  Hann Ling Wong; Tsutomu Kawasaki; Ko Shimamoto

  ADVANCES IN GENETICS, GENOMICS AND CONTROL OF RICE BLAST DISEASE SPRINGER 173 - + 2009 

  Reactive oxygen species (ROS) produced by NADPH oxidase play critical roles in various plant growth, development and defense against pathogens. Plant NADPH oxidases are called regulatory burst oxidase homolog or Rboh. Although Rboh has been isolated from numerous plant species, the molecular mechanism of the regulation of its enzymatic activity remains unclear. All rboh genes identified to date possess a conserved N-terminal extension that contains two Ca2+-binding EF-hand motifs. This N-terminal region may provide an entry point for Ca2+ to participate in ROS signaling. In phagocyte NADPH oxidase, the small GTPase Rac2 plays the role of a key regulator. In plants, Rac GTPases are also involved in regulation of ROS production and resistance to pathogens in rice. This review discusses recent findings that provide key clues to the understanding of molecular regulation of Rboh by Rac GTPase.
• Crystallographic characterization of the N-terminal domain of a plant NADPH oxidase

  Takashi Oda; Hiroshi Hashimoto; Naoyuki Kuwabara; Kokoro Hayashi; Chojiro Kojima; Tsutomu Kawasaki; Ko Shimamoto; Mamoru Sato; Toshiyuki Shimizu

  ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS INT UNION CRYSTALLOGRAPHY 64 867 - 869 2053-230X 2008/09 [Refereed]
   

  Respiratory burst oxidase homologue (Rboh), which is found in the plasma membrane, is a generator of reactive oxygen species (ROS) in plants. Many studies have indicated that the ROS produced by Rboh play critical roles in various cellular activities, including plant defence against pathogens. Crystals of the N-terminal domain of Oryza sativa RbohB (OsRbohB) have been obtained. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 60.4, b = 72.2, c = 118.9 angstrom. An intensity data set was collected to 2.4 angstrom resolution.
• RACK1 functions in rice innate immunity by interacting with the rac1 immune complex

  Ayako Nakashima; Letian Chen; Nguyen Phuong Thao; Masayuki Fujiwara; Hann Ling Wong; Masayoshi Kuwano; Kenji Umemura; Ken Shirasu; Tsutomu Kawasaki; Ko Shimamoto

  PLANT CELL AMER SOC PLANT BIOLOGISTS 20 (8) 2265 - 2279 1040-4651 2008/08 [Refereed]
   

  A small GTPase, Rac1, plays a key role in rice (Oryza sativa) innate immunity as part of a complex of regulatory proteins. Here, we used affinity column chromatography to identify rice RACK1 (for Receptor for Activated C-Kinase 1) as an interactor with Rac1. RACK1 functions in various mammalian signaling pathways and is involved in hormone signaling and development in plants. Rice contains two RACK1 genes, RACK1A and RACK1B, and the RACK1A protein interacts with the GTP form of Rac1. Rac1 positively regulates RACK1A at both the transcriptional and posttranscriptional levels. RACK1A transcription was also induced by a fungal elicitor and by abscisic acid, jasmonate, and auxin. Analysis of transgenic rice plants and cell cultures indicates that RACK1A plays a role in the production of reactive oxygen species (ROS) and in resistance against rice blast infection. Overexpression of RACK1A enhances ROS production in rice seedlings. RACK1A was shown to interact with the N terminus of NADPH oxidase, RAR1, and SGT1, key regulators of plant disease resistance. These results suggest that RACK1A functions in rice innate immunity by interacting with multiple proteins in the Rac1 immune complex.
• Constitutive activation of a CC-NB-LRR protein alters morphogenesis through the cytokinin pathway in Arabidopsis

  Kadunari Igari; Sachiko Endo; Ken-ichiro Hibara; Mitsuhiro Aida; Hitoshi Sakakibara; Tsutomu Kawasaki; Masao Tasaka

  PLANT JOURNAL WILEY-BLACKWELL 55 (1) 14 - 27 0960-7412 2008/07 [Refereed]
   

  Possible links between plant defense responses and morphogenesis have been postulated, but their molecular nature remains unknown. Here, we introduce the Arabidopsis semi-dominant mutant uni-1D with morphological defects. UNI encodes a coiled-coil nucleotide-binding leucine-rich-repeat protein that belongs to the disease resistance (R) protein family involved in pathogen recognition. The uni-1D mutation causes the constitutive activation of the protein, which is stabilized by the RAR1 function in a similar way as in other R proteins. The uni-1D mutation induces the upregulation of the Pathogenesis-related gene via the accumulation of salicylic acid, and evokes some of the morphological defects through the accumulation of cytokinin. The rin4 knock-down mutation, which causes the constitutive activation of two R proteins, RPS2 and RPM1, induces an upregulation of cytokinin-responsive genes and morphological defects similar to the uni-1D mutation, indicating that the constitutive activation of some R proteins alters morphogenesis through the cytokinin pathway. From these data, we propose that the modification of the cytokinin pathway might be involved in some R protein-mediated responses.
• Crystallographic characterization of the N-terminal domain of a plant NADPH oxidase

  Takashi Oda; Hiroshi Hashimoto; Naoyuki Kuwabara; Kokoro Hayashi; Chojiro Kojima; Tsutomu Kawasaki; Ko Shimamoto; Mamoru Sato; Toshiyuki Shimizu

  Acta Crystallographica Section F: Structural Biology and Crystallization Communications 64 (9) 867 - 869 1744-3091 2008 [Refereed]
   

  Respiratory burst oxidase homologue (Rboh), which is found in the plasma membrane, is a generator of reactive oxygen species (ROS) in plants. Many studies have indicated that the ROS produced by Rboh play critical roles in various cellular activities, including plant defence against pathogens. Crystals of the N-terminal domain of Oryza sativa RbohB (OsRbohB) have been obtained. The crystals belonged to space group P212121, with unit-cell parameters a = 60.4, b = 72.2, c = 118.9 Å. An intensity data set was collected to 2.4 Å resolution.
• Regulation of rice NADPH oxidase by binding of Rac GTPase to its N-terminal extension

  Hann Ling Wong; Reinhard Pinontoan; Kokoro Hayashi; Ryo Tabata; Takashi Yaeno; Kana Hasegawa; Chojiro Kojima; Hirofumi Yoshioka; Koh Iba; Tsutomu Kawasaki; Ko Shimamoto

  PLANT CELL AMER SOC PLANT BIOLOGISTS 19 (12) 4022 - 4034 1040-4651 2007/12 [Refereed]
   

  Reactive oxygen species (ROS) produced by NADPH oxidase play critical roles in various cellular activities, including plant innate immunity response. In contrast with the large multiprotein NADPH oxidase complex of phagocytes, in plants, only the homologs of the catalytic subunit gp91(phox) and the cytosolic regulator small GTPase Rac are found. Plant homologs of the gp91phox subunit are known as Rboh (for respiratory burst oxidase homolog). Although numerous Rboh have been isolated in plants, the regulation of enzymatic activity remains unknown. All rboh genes identified to date possess a conserved N-terminal extension that contains two Ca2+ binding EF-hand motifs. Previously, we ascertained that a small GTPase Rac (Os Rac1) enhanced pathogen-associated molecular pattern-induced ROS production and resistance to pathogens in rice (Oryza sativa). In this study, using yeast two-hybrid assay, we found that interaction between Rac GTPases and the N-terminal extension is ubiquitous and that a substantial part of the N-terminal region of Rboh, including the two EF-hand motifs, is required for the interaction. The direct Rac-Rboh interaction was supported by further studies using in vitro pull-down assay, a nuclear magnetic resonance titration experiment, and in vivo fluorescence resonance energy transfer (FRET) microscopy. The FRET analysis also suggests that cytosolic Ca2+ concentration may regulate Rac-Rboh interaction in a dynamic manner. Furthermore, transient coexpression of Os Rac1 and rbohB enhanced ROS production in Nicotiana benthamiana, suggesting that direct Rac-Rboh interaction may activate NADPH oxidase activity in plants. Taken together, the results suggest that cytosolic Ca2+ concentration may modulate NADPH oxidase activity by regulating the interaction between Rac GTPase and Rboh.
• RAR1 and HSP90 form a complex with Rac/Rop GTPase and function in innate-immune responses in rice

  Nguyen Phuong Thao; Letian Chen; Ayako Nakashima; Shin-ichiro Hara; Kenji Umemura; Akira Takahashi; Ken Shirasu; Tsutomu Kawasaki; Ko Shimamoto

  PLANT CELL AMER SOC PLANT BIOLOGISTS 19 (12) 4035 - 4045 1040-4651 2007/12 [Refereed]
   

  A rice (Oryza sativa) Rac/Rop GTPase, Os Rac1, is involved in innate immunity, but its molecular function is largely unknown. RAR1 ( for required for Mla12 resistance) and HSP90 ( a heat shock protein 90 kD) are important components of R gene mediated disease resistance, and their function is conserved in several plant species. HSP90 has also recently been shown to be important in mammalian innate immunity. However, their functions at the molecular level are not well understood. In this study, we examined the functional relationships between Os Rac1, RAR1, and HSP90. Os RAR1-RNA interference (RNAi) rice plants had impaired basal resistance to a compatible race of the blast fungus Magnaporthe grisea and the virulent bacterial blight pathogen Xanthomonas oryzae. Constitutively active Os Rac1 complemented the loss of resistance, suggesting that Os Rac1 and RAR1 are functionally linked. Coimmunoprecipitation experiments with rice cell culture extracts indicate that Rac1 forms a complex with RAR1, HSP90, and HSP70 in vivo. Studies with Os RAR1-RNAi and treatment with geldanamycin, an HSP90-specific inhibitor, showed that RAR1 and HSP90 are essential for the Rac1-mediated enhancement of pathogen-associated molecular pattern-triggered immune responses in rice cell cultures. Furthermore, the function of HSP90, but not RAR1, may be essential for their association with the Rac1 complex. Os Rac1 also regulates RAR1 expression at both the mRNA and protein levels. Together, our results indicate that Rac1, RAR1, HSP90, and HSP70 form one or more protein complexes in rice cells and suggest that these proteins play important roles in innate immunity in rice.
• Rice Pti1a negatively regulates RAR1-dependent Defense responses

  Akira Takahashi; Ganesh Kumar Agrawal; Muneo Yamazaki; Katsura Onosato; Akio Miyao; Tsutomu Kawasaki; Ko Shimamoto; Hirohiko Hirochika

  PLANT CELL AMER SOC PLANT BIOLOGISTS 19 (9) 2940 - 2951 1040-4651 2007/09 [Refereed]
   

  Tomato (Solanum lycopersicum) Pto encodes a protein kinase that confers resistance to bacterial speck disease. A second protein kinase, Pti1, physically interacts with Pto and is involved in Pto-mediated defense signaling. Pti1-related sequences are highly conserved among diverse plant species, including rice ( Oryza sativa), but their functions are largely unknown. Here, we report the identification of a null mutant for the Pti1 homolog in rice and the functional characterization of Os Pti1a. The rice pti1a mutant was characterized by spontaneous necrotic lesions on leaves, which was accompanied by a series of defense responses and resistance against a compatible race of Magnaporthe grisea. Overexpression of Pti1a in rice reduced resistance against an incompatible race of the fungus recognized by a resistance ( R) protein, Pish. Plants overexpressing Pti1a were also more susceptible to a compatible race of the bacterial pathogen Xanthomonas oryzae pv oryzae. These results suggest that Os Pti1a negatively regulates defense signaling for both R gene-mediated and basal resistance. We also demonstrated that repression of the rice RAR1 gene suppressed defense responses induced in the pti1a mutant, indicating that Pti1a negatively regulates RAR1-dependent defense responses. Expression of a tomato Pti1 cDNA in the rice pti1a mutant suppressed the mutant phenotypes. This contrasts strikingly with the previous finding that SI Pti1 enhances Pto-mediated hypersensitive response (HR) induction when expressed in tobacco ( Nicotiana tabacum), suggesting that the molecular switch controlling HR downstream of pathogen recognition has evolved differently in rice and tomato.
• Regulation of the rice NADPH oxidase by binding of small GTPase Rac and Ca2+ to its N-terminal extension

  Hann Ling Wong; Reinhard Pinontoan; Kana Hasegawa; Takashi Yaeno; Koh Iba; Ryo Tabata; Kokoro Hayashi; Chojiro Kojima; Tsutomu Kawasaki; Ko Shimamoto

  BIOTECHNOLOGY AND SUSTAINABLE AGRICULTURE 2006 AND BEYOND SPRINGER 209 - + 2007 [Refereed]
  
• Gタンパク質を介した病原体認識シグナルの伝達

  川崎努; 島本功

  植物感染生理談話会論文集 43 29 - 36 2007
• Molecular signaling in disease resistance of rice.

  Shimamoto, K; Nakashima, A; Fujiwara, M; Thao, N.P; Chen, L; Wong; H.L. Miki, D; Imai,K; Maisonneuve, S; Takahashi, H; Kawaguchi, Y; Hirai, S; Kawasaki, T

  Rice Genetics V 143 - 152 2007
• Proteomics of Rac GTPase signaling reveals its predominant role in elicitor-induced defense response of cultured rice cells

  M Fujiwara; K Umemura; T Kawasaki; K Shimamoto

  PLANT PHYSIOLOGY AMER SOC PLANT BIOLOGISTS 140 (2) 734 - 745 0032-0889 2006/02 [Refereed]
   

  We have previously shown that a human small GTPase Rac homolog, OsRac1, from rice (Oryza sativa) induces cascades of defense responses in rice plants and cultured cells. Sphingolipid elicitors (SEs) have been similarly shown to activate defense responses in rice. Therefore, to systematically analyze proteins whose expression levels are altered by OsRac1 and/or SE treatment, we performed a differential display analysis of proteins by the use of two-dimensional gel electrophoresis and mass spectrometry. A total of 271 proteins whose expression levels were altered by constitutively active (CA)-OsRac1 or SE were identified. Interestingly, of 100 proteins that were up-regulated by a SE, 87 were also induced by CA-OsRac1, suggesting that OsRac1 plays a pivotal role in defense responses induced by SE in cultured rice cells. In addition, CA-OsRac1 induces the expression of 119 proteins. Many proteins, such as pathogenesis-related proteins, SGT1, and prohibitin, which are known to be involved in the defense response, were found among these proteins. Proteins involved in redox regulation, chaperones such as heat shock proteins, BiP, and chaperonin 60, proteases and protease inhibitors, cytoskeletal proteins, subunits of proteasomes, and enzymes involved in the phenylpropanoid and ethylene biosynthesis pathways were found to be induced by CA-OsRac1 or SE. Results of our proteomic analysis revealed that OsRac1 is able to induce many proteins in various signaling and metabolic pathways and plays a predominant role in the defense response in cultured rice cells.
• Cinnamoyl-CoA reductase, a key enzyme in lignin biosynthesis, is an effector of small GTPase Rac in defense signaling in rice

  T Kawasaki; H Koita; T Nakatsubo; K Hasegawa; K Wakabayashi; H Takahashi; K Urnemura; T Urnezawa; K Shimamoto

  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA NATL ACAD SCIENCES 103 (1) 230 - 235 0027-8424 2006/01 [Refereed]
   

  OsRac1, one of the Rac/Rop family of small GTPases, plays important roles in defense responses, including a role in the production of reactive oxygen species mediated by NADPH oxidase. We have identified an effector of OsRac1, namely rice (Oryza sativa) cinnamoyl-CoA reductase 1 (OsCCR1), an enzyme involved in lignin biosynthesis. Lignin, which is polymerized through peroxiclase activity by using H2O2 in the cell wall, is an important factor in plant defense responses, because it presents an undegradable mechanical barrier to most pathogens. Expression of OsCCR1 was induced by a sphingolipid elicitor, suggesting that OsCCR1 participates in defense signaling. In in vitro interaction and two-hybrid experiments, OsRac1 was shown to bind OsCCR1 in a GTP-dependent manner. Moreover, the interaction of OsCCR1 with OsRac1 led to the enzymatic activation of OsCCR1 in vitro. Transgenic cell cultures expressing the constitutively active OsRac1 accumulated lignin through enhanced CCR activity and increased reactive oxygen species production. Thus, it is likely that OsRac1 controls lignin synthesis through regulation of both NADPH oxiclase and OsCCR1 activities during defense responses in rice.
• 1P022 The crystal structure of N-terminal domain of plants NADPH oxidase(1. Protein structure and dynamics (I),Poster Session,Abstract,Meeting Program of EABS & BSJ 2006)

  Oda Takashi; Hayashi Kokoro; Kojima Chojiro; Hashimoto Hiroshi; Kawasaki Tsutomu; Shimamoto Ko; Sato Mamoru; Shimizu Toshiyuki

  Seibutsu Butsuri The Biophysical Society of Japan General Incorporated Association 46 (2) S152  0582-4052 2006
• A duplicated pair of Arabidopsis RING-finger E3 ligases contribute to the RPM1-and RPS2-mediated hypersensitive response

  T Kawasaki; J Nam; DC Boyes; BF Holt; DA Hubert; A Wiig; JL Dangl

  PLANT JOURNAL BLACKWELL PUBLISHING 44 (2) 258 - 270 0960-7412 2005/10 [Refereed]
   

  The Arabidopsis RPM1 protein confers resistance to disease caused by Pseudomonas syringae strains delivering either the AvrRpm1 or AvrB type III effector proteins into host cells. We characterized two closely related RPM1-interacting proteins, RIN2 and RIN3. RIN2 and RIN3 encode RING-finger type ubiquitin ligases with six apparent transmembrane domains and an ubiquitin-binding CUE domain. RIN2 and RIN3 are orthologs of the mammalian autocrine motility factor receptor, a cytokine receptor localized in both plasma membrane caveolae and the endoplasmic reticulum. RIN2 is predominantly localized to the plasma membrane, as are RPM1 and RPS2. The C-terminal regions of RIN2 and RIN3, including the CUE domain, interact strongly with an RPM1 N-terminal fragment and weakly with a similar domain from the Arabidopsis RPS2 protein. RIN2 and RIN3 can dimerize through their C-terminal regions. The RING-finger domains of RIN2 and RIN3 encode ubiquitin ligases. Inoculation with A syringae DC3000(avrRpm1) or A syringae DC3000(avrRpt2) induces differential decreases of RIN2 mobility in SDS-PAGE and disappearance of the majority of RIN2. A rin2 rin3 double mutant expresses diminished RPM1- and RPS2-dependent hypersensitive response (HR), but no alteration of pathogen growth. Thus, the RIN2/RIN3 RING E3 ligases apparently act on a substrate that regulates RPM1- and RPS2-dependent HR.
• A sphingolipid elicitor-inducible mitogen-activated protein kinase is regulated by the small GTPase OsRac1 and heterotrimeric G-protein in rice

  D Lieberherr; NP Thao; A Nakashima; K Umemura; T Kawasaki; K Shimamoto

  PLANT PHYSIOLOGY AMER SOC PLANT BIOLOGISTS 138 (3) 1644 - 1652 0032-0889 2005/07 [Refereed]
   

  Mitogen-activated protein kinase (MAPK) cascades are activated in plants during responses to pathogens or to pathogen-derived elicitors and mediate intracellular stress responses. Here, we show that a rice (Oryza sativa) MAPK, OsMAPK6, was post-translationally activated in a cell culture by a sphingolipid elicitor. Suppression of OsMAPK6 expression by RNA interference resulted in a strong reduction of pathogen-induced Phe ammonia-lyase mRNA, whereas the mRNA level of another rice MAPK, OsMAPK5a, was highly increased. Silencing of a small GTPase, OsRac1, by RNA interference or loss-of- function mutation (d1) of the heterotrimeric G-protein alpha-subunit gene resulted in a strong reduction of the OsMAPK6protein levels and of kinase activation by a sphingolipid elicitor. Furthermore, coimmunoprecipitation experiments with OsRac1 and OsMAPK6 proteins showed that OsMAPK6 is closely associated with the active form of OsRac1, but not with inactive forms of OsRac1. These results indicate that these two G-proteins regulate an elicitor-inducible MAPK in rice at the protein level.
• Proteome analysis of programmed cell death and defense signaling using the rice lesion mimic mutant cdr2

  H Tsunezuka; M Fujiwara; T Kawasaki; K Shimamoto

  MOLECULAR PLANT-MICROBE INTERACTIONS AMER PHYTOPATHOLOGICAL SOC 18 (1) 52 - 59 0894-0282 2005/01 [Refereed]
   

  We have previously identified three lesion-mimic mutants, cell death and resistance (cdr), in rice. These mutants induce a series of defense responses, including expression of defense-related genes and high accumulation of phytoalexins, indicating that the cdr mutants are useful materials to study programmed cell death and defense signaling in rice. Here, we carried out a proteome analysis of the cdr2 mutant. Total proteins prepared from the wild type and the cdr2 mutant at three different stages of lesion formation were compared using two-dimensional electrophoresis. We found a total of 37 proteins that were differentially expressed between cdr2 and wild type. Among them, 28 spots were up-regulated and nine were down-regulated in the cdr2 mutant. All the protein spots were identified by mass spectrometric analysis. These differentially regulated proteins included defense-related proteins. In addition, 27 proteins were classified as metabolic enzymes, suggesting that the programmed cell death that occurs in the cdr2 mutant is associated with active metabolic changes. Our study shows that proteome analysis is a useful approach to study programmed cell death and defense signaling in plants.
• Gタンパク質を介した病原体認識と耐病性シグナリング

  川崎 努; 島本 功

  植物感染生理談話会論文集 41 23 - 30 2005
• Down-regulation of metallothionein, a reactive oxygen scavenger, by the small GTPase OsRac1 in rice

  HL Wong; T Sakamoto; T Kawasaki; K Umemura; K Shimamoto

  PLANT PHYSIOLOGY AMER SOC PLANT BIOLOGISTS 135 (3) 1447 - 1456 0032-0889 2004/07 [Refereed]
   

  Metallothioneins are small, ubiquitous Cys-rich proteins known to be involved in reactive oxygen species (ROS) scavenging and metal homeostasis. We found that the expression of a metallothionein gene (OsMT2b) was synergically down-regulated by OsRac1 and rice (Oryza sativa) blast-derived elicitors. Transgenic plants overexpressing OsMT2b showed increased susceptibility to bacterial blight and blast fungus. OsMT2b-overexpressing cells showed reduced elicitor-induced hydrogen peroxide production. In contrast, homozygous OsMT2b::Tbs17-inserted mutant and OsMT2b-RNAi-silenced transgenic cells showed significantly higher elicitor-induced hydrogen peroxide production than the wild-type cells. In vitro assay showed that recombinant OsMT2b protein possessed superoxide- and hydroxyl radical-scavenging activities. Taken together, these results showed that OsMT2b is an ROS scavenger and its expression is down-regulated by OsRac1, thus potentiating ROS, which function as signals in resistance response. The results suggest that OsRac1. plays a dual role as an inducer of ROS production and a suppressor of ROS scavenging.
• イネの防御反応

  川崎努

  植物感染生理談話会論文集 40 69 - 76 2004
• Hyperphosphorylation of a mitochondrial protein, prohibitin, is induced by calyculin A in a rice lesion-mimic mutant cdr1

  A Takahashi; T Kawasaki; HL Wong; U Suharsono; H Hirano; K Shimamoto

  PLANT PHYSIOLOGY AMER SOC PLANT BIOLOGISTS 132 (4) 1861 - 1869 0032-0889 2003/08 [Refereed]
   

  The rice (Oryza saliva) lesion-mimic mutants, cell death and resistance (cdr), show spontaneous cell death on the entire leaf and exhibited significant resistance to the rice blast fungus. Our previous studies showed that CDR1 and CDR2 genes negatively regulated the phosphorylation steps leading to the activation of NADPH oxidase, which is associated with oxidative burst. To identify novel factors involved in the phosphorylation steps, the phosphorylation level of total proteins was compared between cdr mutants and wild type using two-dimensional gel electrophoresis. Here, we show that the phosphorylation level of four proteins in cdr1 was increased as compared with the wild type after calyculin A treatment. Partial amino acid sequences revealed that one of the four proteins is homologous to prohibitin (PHB), which has been shown to be associated with senescence and cell death and to function as a chaperone in the assembly of mitochondrial respiratory chain complex in yeast and mammals. Analysis of green fluorescent protein fusions indicated that rice PHB (OsPHB1) was targeted to mitochondria as found in yeast and mammals, suggesting a possibility that PHB is involved in defense response and/or programmed cell death through the mitochondrial function.
• Isolation d characterization of starch mutants in rice.

  Satoh, H; Nishi, A; Fujita, N; Kubo, A; Nakamura, Y; Kawasaki, T; Okita, T

  J. Appl. Glycosci. The Japanese Society of Applied Glycoscience 50 (2) 225 - 230 1344-7882 2003 

  We isolated various kinds of mutants participating in the biosynthesis of endosperm starch by the MNU treatment of fertilized egg cells in japonica rice cultivars. There were at least 6 mutant loci lowering amylose content including the wx locus. These low amylose mutations altered the amylose content without affecting the amylopectin structure. The amylose content did not affect the initiation of gelatinization, but influenced greatly the swelling of gel, indicating that amylose content affects the swelling power of gel and the termination of gelatinization. BEIIb mutation decreased specifically the short chains with DP less than 17 in amylopectin whereas BEI mutation was characterized by a significant decrease in long chains with DP longer than 38 and short chains with DP 12 to 23, suggesting that BEIIb and BEI contributes to the synthesis of A chains, and B, and B3 chains of amylopectin, respectively. Notable alteration on the chain length profile was not observed in BEIIa mutation. Each BE mutation showed distinct effect on the thermal properties of endosperm starch. The sug2 mutation lowering the expression level of PUL increased shorter chains of amylopectin and accumulated a significant amount of the water-soluble polysaccharides as well as ISA (sugl ) mutation. The fl o2 mutation decreased simultaneously the expression levels of some of the enzymes including BEI, PUL and GBSS, suggesting that the wild type Flo2 gene probably encodes a regulatory protein that modulates the expression of the genes involved in starch biosynthesis. Some mutants involved in the biosyn thesis of ADP-glucose were also isolated.
• The heterotrimeric G protein alpha subunit acts upstream of the small GTPase Rac in disease resistance of rice

  U Suharsono; Y Fujisawa; T Kawasaki; Y Iwasaki; H Satoh; K Shimamoto

  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA NATL ACAD SCIENCES 99 (20) 13307 - 13312 0027-8424 2002/10 [Refereed]
   

  We used rice dwarf1 (d1) mutants lacking a single-copy Galpha gene and addressed Galpha's role in disease resistance. d1 mutants exhibited a highly reduced hypersensitive response to infection by an avirulent race of rice blast. Activation of PR gene expression in the leaves of the mutants infected with rice blast was delayed for 24 h relative to the wild type. H2O2 production and PR gene expression induced by sphingolipid elicitors (SE) were strongly suppressed in d1 cell cultures. Expression of the constitutively active OsRac1, a small GTPase Rac of rice, in d1 mutants restored SE-dependent defense signaling and resistance to rice blast. Galpha mRNA was induced by an avirulent race of rice blast and SE application on the leaf. These results indicated the role of Galpha in R gene-mediated disease resistance of rice. We have proposed a model for the defense signaling of rice in which the heterotrimeric G protein functions upstream of the small GTPase OsRac1 in the early steps of signaling.
• Rice SPK, a calmodulin-like domain protein kinase, is required for storage product accumulation during seed development: Phosphorylation of sucrose synthase is a possible factor

  T Asano; N Kunieda; Y Omura; H Ibe; T Kawasaki; M Takano; M Sato; H Furuhashi; T Mujin; F Takaiwa; CY Wu; Y Tada; T Satozawa; M Sakamoto; H Shimada

  PLANT CELL AMER SOC PLANT BIOLOGISTS 14 (3) 619 - 628 1040-4651 2002/03 [Refereed]
   

  Sue, an end product of photosynthesis, is metabolized by Sue synthase in sink organs as an initial step in the biosynthesis of storage products. Sue synthase activity is known to be regulated by reversible phosphorylation, but the details of this process are unclear at present. Rice SPK, a calcium-dependent protein kinase, is expressed uniquely in the endosperm of immature seed, and its involvement in the biosynthetic pathways of storage products was suggested. Antisense SPK transformants lacked the ability to accumulate storage products such as starch, but produced watery seed with a large amount of Sue instead, as the result of an inhibition of Sue degradation. Analysis of in vitro phosphorylation indicated that SPK phosphorylated specifically a Ser residue in Sue synthase that has been shown to be important for its activity in the degradation of Sue. This finding suggests that SPK is involved in the activation of Sue synthase. It appears that SPK is a Sue synthase kinase that may be important for supplying substrates for the biosynthesis of storage products.
• G protein signaling in disease resistance of rice

  Shimamoto, K; Suharsono, U; Ono, E; Wong, H.L; anf Kawasaki, T

  Biology of Plant-Microbe Interactions. 3 83 - 87 2002
• Characterization of an isoform of rice starch branching enzyme, RBE4, in developing seeds

  K Mizuno; E Kobayashi; M Tachibana; T Kawasaki; T Fujimura; K Funane; M Kobayashi; T Baba

  PLANT AND CELL PHYSIOLOGY OXFORD UNIV PRESS 42 (4) 349 - 357 0032-0781 2001/04 [Refereed]
   

  cDNA clones encoding an isoform of starch branching enzyme, RBE4, have been identified from a developing rice seed cDNA library, using a synthetic oligonucleotide probe corresponding to the N-terminal amino acid sequence of RBE4, The cDNA-derived amino acid sequence indicated that RBE4 is initially produced as a precursor protein of 841 amino acids, including a 53-residue transit peptide at the N-terminus. The mature form of RBE4 shared a high degree of sequence identity (80%) with mature RBE3, and possessed an N-terminal extra sequence, as found in RBE3, Northern blot analysis demonstrated that the RBE4 gene is expressed in both leaves and developing seeds. The RBE4 gene was distinguished from the RBE1 and RBE3 genes by expression at the earlier stages of seed development. To examine enzymatic functions of RBE4, recombinant proteins were produced in Escherichia coli cells, and purified by two chromatographic separations. The branched alpha -glucans produced by the recombinant enzymes from potato amylose revealed the different patterns of oligosaccharide chain transfer. The peak of major branches of the products by RBE3 or RBE4 was 6 glucose units, whereas the peaks of major branches of the products by RBE1 were 6 and 11 glucose units. The similar property between RBE3 and RBE4 is supported by high similarity of the amino acid sequences between them.
• Essential role of the small GTPase Rac in disease resistance of rice

  E Ono; HL Wong; T Kawasaki; M Hasegawa; O Kodama; K Shimamoto

  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA NATL ACAD SCIENCES 98 (2) 759 - 764 0027-8424 2001/01 [Refereed]
   

  Production of reactive oxygen intermediates (ROI) and a form of programmed cell death called hypersensitive response (HR) are often associated with disease resistance of plants. We have previously shown that the Pac homolog of rice, OsRac1, is a regulator of ROI production and cell death in rice. Here we show that the constitutively active OsRac1 (i) causes HR-like responses and greatly reduces disease lesions against a virulent race of the rice blast fungus; (ii) causes resistance against a Virulent race of bacterial blight; and (iii) causes enhanced production of a phytoalexin and alters expression of defense-related genes. The dominant-negative OsRac1 suppresses elicitor-induced ROI production in transgenic cell cultures, and in plants suppresses the HR induced by the avirulent race of the fungus. Taken together, our findings strongly suggest that OsRac1 has a general role in disease resistance of rice.
• Molecular signaling in disease resistance of rice.

  Shimamoto, K; Takahashi, A; Kawasaki, T

  Rice Genetics IV 323 - 333 2001
• The small GTP-binding protein Rac is a regulator of cell death in plants

  T Kawasaki; K Henmi; E Ono; S Hatakeyama; M Iwano; H Satoh; K Shimamoto

  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA NATL ACAD SCIENCES 96 (19) 10922 - 10926 0027-8424 1999/09 [Refereed]
   

  Cell death plays important roles in the development and defense of plants as in other multicellular organisms. Rapid production of reactive oxygen species often is associated with plant defense against pathogens, but their molecular mechanisms are not known, We introduced the constitutively active and the dominant negative forms of the small GTP-binding protein OsRac1, a rice homolog of human Rac, into the wild type and a lesion mimic mutant of rice and analyzed H2O2 production and cell death in transformed cell cultures and plants. The results indicate that Rac is a regulator of reactive oxygen species production as well as cell death in rice.
• RNA maturation of the rice SPK gene may involve trans-splicing

  T Kawasaki; S Okumura; N Kishimoto; H Shimada; K Higo; N Ichikawa

  PLANT JOURNAL BLACKWELL SCIENCE LTD 18 (6) 625 - 632 0960-7412 1999/06 [Refereed]
   

  A gene encoding a calcium-dependent seed-specific protein kinase (SPK) is abundantly expressed in developing rice seeds (Kawasaki, T, et al. Gene (1993) 129, 183-189). Rice genomic clones encoding SPK were isolated using the entire cDNA fragment as a probe. Physical mapping of these genomic clones indicated that the genomic region corresponding to the entire cDNA was divided into two different regions, SPK-A and SPK-B, located on different rice chromosomes. The results of RACE-PCR analyses showed that the respective transcripts from SPK-A and SPK-B contained additional sequences which were not found in the SPK cDNA, and that these sequences were removed like introns during maturation of the SPK mRNA. These results suggest that two different RNAs were independently transcribed from SPK-A and SPK-B and joined, possibly by trans-splicing.
• Lesion mimic mutants of rice with alterations in early signaling events of defense

  A Takahashi; T Kawasaki; K Henmi; K Shii; O Kodama; H Satoh; K Shimamoto

  PLANT JOURNAL BLACKWELL SCIENCE LTD 17 (5) 535 - 545 0960-7412 1999/03 [Refereed]
   

  We screened 93 lesion mimic mutants of rice for resistance to the blast fungus, Magnaporthe grisea, and found eight mutants that exhibited significant resistance to the fungus. We called these mutants cdr (cell death and resistance) and further analyzed three of them. Two mutations, cdr1 and cdr2,were recessive and one, Cdr3, was dominant. Many small brownish lesions developed over the entire leaf of the mutants 20-50 days after sowing. TUNEL staining revealed that DNA fragmentation occurred in leaf blade cells of the homozygous Cdr3 mutants. Autofluorescence and callose deposition were visible in leaf cells of these three mutants. Activation of two defense-related genes, PBZ1 and PR1, was observed in the leaves of the mutants; high expression of PBZ1 was correlated with the lesion formation in the three mutants, whereas PR1 was constitutively expressed in the cdr2 and Cdr3 mutants irrespective of the lesion formation. Levels of momilactone A, a major phytoalexin of rice, in these mutants were increased approximately 100-400-fold relative to the wild-type levels. Suspension-cultured cells of the cdr1 and cdr2 but not Cdr3 produced higher levels of H2O2 than the wild type when treated with calyculin A, an inhibitor of protein phosphatase 1. These results suggest that biochemical lesions of cdr1 and cdr2 lie in the early signaling steps leading to activation of the NADPH oxidase and that type-1 protein phosphatase is operative in protein dephosphorylation involved in NADPH oxidase activation.
• Programmed cell death in plants

  Shimamoto, K; Takahashi, A; Henmi, K; Ono, E; Hatakeyama, S; Iwano, M; Kawasaki, T

  Plant Biotechnology Japanese Society for Plant Cell and Molecular Biology 16 (1) 49 - 53 1342-4580 1999 

  There is increasing evidence for occurrence of programmed cell death (PCD) in plant development, plant-microbe interaction and cells under a variety of stresses. Recent studies on PCD in plants indicate that various features of apoptosis in mammals are shared with plant PCD: there is evidence for DNA fragmentation, oligonucleosomal DNA laddering, morphological changes in plant cells. These studies suggest that PCD plays an important role in the life of plants as in animals. Despite the wide occurrence of PCD in plants, signaling and components of the machinery for PCD are largely unknown. We recently identified the Rac family of the small GTP-binding protein as a key regulator of PCD in plants. Also, the analysis of lesion mimic mutants of rice indicates that some mutants have biochemical alterations in early steps of signaling in disease resistance. The major challenge in the study of plant PCD in the near future is the identification of signaling molecules and components of machinery involved in plant PCD. This will enable us to better understand this important cellular process of plants.
• Coordinated regulation of the genes participating in starch biosynthesis by the rice Floury-2 locus

  T Kawasaki; K Mizuno; H Shimada; H Satoh; N Kishimoto; S Okumura; N Ichikawa; T Baba

  PLANT PHYSIOLOGY AMER SOC PLANT PHYSIOLOGISTS 110 (1) 89 - 96 0032-0889 1996/01 [Refereed]
   

  The recessive floury-2 (flo-2) locus of rice (Oryza sativa L.), which is located on chromosome 4, causes a strong reduction in expression of the gene encoding an isoform of branching enzyme RBE1 in immature seeds 10 d after flowering. Mapping of the RBE1 gene demonstrated the localization on rice chromosome 6, suggesting that the wild-type Floury-2 (Flo-2) gene regulates RBE1 gene expression in trans. However, reduced expression of the genes encoding some other starch-synthesizing enzymes, including another isoform of branching enzyme RBE3 and granule-bound starch synthase, was also found in the flo-2 seeds. In spite of the low level of RBE1 gene expression in the immature seeds of the flo-2 mutants, the RBE1 gene was equally expressed in the leaves of the wild type and flo-2 mutants. Thus, these results imply that the Flo-2 gene may co-regulate expression of some of the genes participating in starch synthesis possibly in a developing seed-specific manner.
• Coordinated regulation of the genes participating in starch biosynthesis by the rice Floury-2 locus

  Kawasaki, T; Mizuno, K; Shimada, H; Satoh, H; Kishimoto, N; Okumura, S; Ichikawa, N; 馬場, 忠

  Plant Physiol. 110 (1) 89 - 96 1532-2548 1996/01 

  The recessive floury-2 (flo-2) locus of rice (Oryza sativa L.), which is located on chromosome 4, causes a strong reduction in expression of the gene encoding an isoform of branching enzyme RBE1 in immature seeds 10 d after flowering. Mapping of the RBE1 gene demonstrated the localization on rice chromosome 6, suggesting that the wild-type Floury-2 (Flo-2) gene regulates RBE1 gene expression in trans. However, reduced expression of the genes encoding some other starch-synthesizing enzymes, including another isoform of branching enzyme RBE3 and granule-bound starch synthase, was also found in the flo-2 seeds. In spite of the low level of RBE1 gene expression in the immature seeds of the flo-2 mutants, the RBE1 gene was equally expressed in the leaves of the wild type and flo-2 mutants. Thus, these results imply that the Flo-2 gene may co-regulate expression of some of the genes participating in starch synthesis possibly in a developing seed-specific manner.
• GENOMIC ORGANIZATION OF 251 KDA ACETYL-COA CARBOXYLASE GENES IN ARABIDOPSIS - TANDEM GENE DUPLICATION HAS MADE 2 DIFFERENTIALLY EXPRESSED ISOZYMES

  Y YANAI; T KAWASAKI; H SHIMADA; ES WURTELE; BJ NIKOLAU; N ICHIKAWA

  PLANT AND CELL PHYSIOLOGY JAPANESE SOC PLANT PHYSIOLOGISTS 36 (5) 779 - 787 0032-0781 1995/07 

  Acetyl-CoA carboxylase (ACCase) catalyzes the carboxylation of acetyl-CoA, forming malonyl-CoA a key intermediate in the biosynthesis of fatty acids and a variety of secondary metabolites. Based upon amino acid sequences conserved among rat, chicken, and E. coli ACCases, PCR-primers were used to amplify a genomic fragment which codes for an ACCase of Arabidopsis. The resulting fragment was used for isolation of genomic and cDNA clones. We have determined the complete cDNA sequence coding for an Arabidopsis ACCase consists of 2,254 amino acids with the molecular mass of 251 kDa. This enzyme contains no recognizable plastid transit-peptide sequence. Therefore, this ACCase is presumably the cytosolic isozyme. Southern analysis indicates that there are two ACCase genes in the Arabidopsis genome. Surprisingly, the results of RFLP analysis and physical mapping of the isolated genomic clones demonstrate that these two genes, acc1 and acc2, are contiguously located within a 25-kbp genomic region near the middle of chromosome 1. Both genes are transcriptionally active, as transcripts from each gene were detected by reverse transcription-PCR analysis using gene-specific primers. The acc1 and acc2 transcripts accumulate in leaves and seedlings but only the acc1 transcript accumulates in developing siliques, unexpectedly. The differences in the expression patterns may be indicative of the differential role of the two genes.
• STRUCTURE, ORGANIZATION, AND CHROMOSOMAL LOCATION OF THE GENE ENCODING A FORM OF RICE SOLUBLE STARCH SYNTHASE

  KI TANAKA; S OHNISHI; N KISHIMOTO; T KAWASAKI; T BABA

  PLANT PHYSIOLOGY AMER SOC PLANT PHYSIOLOGISTS 108 (2) 677 - 683 0032-0889 1995/06 [Refereed]
   

  A rice (Oryza sativa L.) genomic clone encoding the gene for a form of soluble starch synthase (SSS1) and its 5'- and 3'-flanking regions has been isolated and sequenced. The SSS1 gene contained 15 exons interrupted by 14 introns. The exon/intron organization of the SSS1 gene was divergent from that of the rice Waxy gene coding for granule-bound starch synthase, thus suggesting that the SSS1 and granule-bound starch synthase genes have evolved from an ancestral gene in a different way or that the two genes are products of different ancestral genes that have converged during evolution. However, these two genes were closely located to each other on rice chromosome 6 at an approximate map distance of 5 centimorgans. The nucleotide sequence of the 5'-end region of the gene is unique because of the presence of some repetitive sequences.
• PRODUCTION OF TERTIARY TRISOMICS IN RICE (ORYZA-SATIVA L)

  KI NONOMURA; A YOSHIMURA; T KAWASAKI; N IWATA

  BREEDING SCIENCE JAPANESE SOC BREEDING 44 (2) 137 - 142 1344-7610 1994/06 

  Tertiary trisomics, cytogenetical variants with an interchanged chromosome in addition to the normal chromosome complement, were produced through systematic three-way crosses (primary trisomics/reciprocal translocations//normal disomics) in rice (Oryza sativa L.). Twenty-five tertiary trisomics were selected on the basis of their morphology and seed fertility in the F1 progenies of the three-way crosses. They were identified by observations of the breeding behavior of their selfed progenies and of chromosomal configurations at meiosis. As the tertiary trisomics produced in this study are useful for chromosome mapping, additional production of tertiary trisomics is under way.
• Production of Tertiary Trisomics in Rice(Oryza sativa L.).

  Nonomura Ken-Ichi; Yoshimura Atsushi; Kawasaki Tsutomu; Iwata Nobuo

  Breeding Science Japanese Society of Breeding 44 (2) 137 - 142 0536-3683 1994 

  Tertiary trisomics, cytogenetical variants with an interchang'ed chromosome in addition to the normal chromosome them complemcnt. were produced through systematic three-way crosses, (primary tris'omics reciprocal translocations normal disomics) in rice (Oryza sativa L.). Twenty-five tertiary trisomics were selected on the basis of their morphology and seed fertility in the Fl prog'enies of the three-way crosses. They were identified by obs'crvations.' of the breeding behavior of their selfed progenies and of chromosomal config'urations at meiosis. As the tertiary trisomics pro duced in this .study are useful for cht'omosome mapping, additional production of tertiary trisomics is under way.
• Molecular Analysis of the Genes Involved in Starch Synthesis

  Tsutomu Kawasaki; Tadashi Baba

  Nippon Nogeikagaku Kaishi 68 (11) 1585 - 1588 0002-1407 1994
• SEQUENCE OF A SOYBEAN (GLYCINE-MAX L) PHOSPHOENOLPYRUVATE CARBOXYLASE CDNA

  A VAZQUEZTELLO; RF WHITTIER; T KAWASAKI; T SUGIMOTO; Y KAWAMURA; D SHIBATA

  PLANT PHYSIOLOGY AMER SOC PLANT PHYSIOLOGISTS 103 (3) 1025 - 1026 0032-0889 1993/11 [Refereed]
  
• IDENTIFICATION, CDNA CLONING, AND GENE-EXPRESSION OF SOLUBLE STARCH SYNTHASE IN RICE (ORYZA-SATIVA L) IMMATURE SEEDS

  T BABA; M NISHIHARA; K MIZUNO; T KAWASAKI; H SHIMADA; E KOBAYASHI; S OHNISHI; K TANAKA; Y ARAI

  PLANT PHYSIOLOGY AMER SOC PLANT PHYSIOLOGISTS 103 (2) 565 - 573 0032-0889 1993/10 [Refereed]
   

  Three forms of soluble starch synthase were resolved by anion-exchange chromatography of soluble extracts from immature rice (Oryza sativa L.) seeds, and each of these forms was further purified by affinity chromatography. The 55-, 57-, and 57-kD proteins in the three preparations were identified as candidates for soluble starch synthase by western blot analysis using an antiserum against rice granule-bound starch synthase. It is interesting that the amino-terminal amino acid sequence was identical among the three proteins, except that the 55-kD protein lacked eight amino acids at the amino terminus. Thus, these three proteins are products of the same gene. The cDNA clones coding for this protein have been isolated from an immature rice seed library in lambdagt11 using synthetic oligonucleotides as probes. The deduced amino acid sequence of this protein contains a lysine-X-glycine-glycine consensus sequence for the ADP-glucose-binding site of starch and glycogen synthases. Therefore, we conclude that this protein corresponds to a form of soluble starch synthase in immature rice seeds. The precursor of the enzyme contains 626 amino acids, including a 113-residue transit peptide at the amino terminus. The mature form of soluble starch synthase shares a significant but low sequence identity with rice granule-bound starch synthase and Escherichia coli glycogen synthase. However, several regions, including the substrate-binding site, are highly conserved among these three enzymes. Blot hybridization analysis demonstrates that the gene encoding soluble starch synthase is a single-copy gene in the rice genome and is expressed in both leaves and immature seeds. These results suggest that soluble and granule-bound starch synthases play distinct roles in starch biosynthesis of plant.
• ALTERATION OF THE STRUCTURAL-PROPERTIES OF STARCH COMPONENTS BY THE LACK OF AN ISOFORM OF STARCH BRANCHING ENZYME IN RICE SEEDS

  K MIZUNO; T KAWASAKI; H SHIMADA; H SATOH; E KOBAYASHI; S OKUMURA; Y ARAI; T BABA

  JOURNAL OF BIOLOGICAL CHEMISTRY AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 268 (25) 19084 - 19091 0021-9258 1993/09 [Refereed]
   

  This study describes the effect of starch-synthesizing enzymes on biosynthesis of storage starch in rice amylose-extender mutants, which contain branched D-glucans with abnormal structures. Western blot analysis indicated that two out of five amylose-extender mutant lines lacked an isoform of starch branching enzyme, termed RBE3, although the levels of granule-bound starch synthase and a major form of branching enzyme, RBE1, were normal in these two mutants. Proteins corresponding to the 87-kDa RBE3 molecule were present in the three other amylose-extender mutants as well as in the wild type. However, the level of branching enzyme activity significantly decreased in all amylose-extender mutants, suggesting that the 87-kDa proteins in these three mutants are inactive forms of RBE3. Therefore, we conclude that formation of the abnormal branched glucans in the amylose-extender mutant of rice is due to the lack of the RBE3 activity. The cDNA clones encoding RBE3 have been identified from a normal rice seed cDNA library in lambdagt11, using a synthetic oligonucleotide as a probe. The deduced amino acid sequence of RBE3 indicates that this protein is initially synthesized as a precursor of 825 amino acids, including a 65-residue transit peptide at the NH2 terminus. The sequences of the catalytic regions in amylolytic enzymes are highly conserved in the sequence of RBE3. Thus, the branching enzyme isoform belongs to a family of the amylolytic enzymes. RBE3 also shares a noticeable degree of sequence identity with RBE1, especially at the central portion of the protein molecule. However, RBE3 possesses an approximately 70-residue extra sequence at the NH2 terminus and lacks a COOH-terminal sequence of almost 50 residues as compared with RBE1. The structural differences at both termini may explain the distinct role in starch synthesis for RBE1 and RBE3.
• ALTERATION OF THE STRUCTURAL-PROPERTIES OF STARCH COMPONENTS BY THE LACK OF AN ISOFORM OF STARCH BRANCHING ENZYME IN RICE SEEDS

  K MIZUNO; T KAWASAKI; H SHIMADA; H SATOH; E KOBAYASHI; S OKUMURA; Y ARAI; T BABA

  JOURNAL OF BIOLOGICAL CHEMISTRY AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC 268 (25) 19084 - 19091 0021-9258 1993/09 

  This study describes the effect of starch-synthesizing enzymes on biosynthesis of storage starch in rice amylose-extender mutants, which contain branched D-glucans with abnormal structures. Western blot analysis indicated that two out of five amylose-extender mutant lines lacked an isoform of starch branching enzyme, termed RBE3, although the levels of granule-bound starch synthase and a major form of branching enzyme, RBE1, were normal in these two mutants. Proteins corresponding to the 87-kDa RBE3 molecule were present in the three other amylose-extender mutants as well as in the wild type. However, the level of branching enzyme activity significantly decreased in all amylose-extender mutants, suggesting that the 87-kDa proteins in these three mutants are inactive forms of RBE3. Therefore, we conclude that formation of the abnormal branched glucans in the amylose-extender mutant of rice is due to the lack of the RBE3 activity. The cDNA clones encoding RBE3 have been identified from a normal rice seed cDNA library in lambdagt11, using a synthetic oligonucleotide as a probe. The deduced amino acid sequence of RBE3 indicates that this protein is initially synthesized as a precursor of 825 amino acids, including a 65-residue transit peptide at the NH2 terminus. The sequences of the catalytic regions in amylolytic enzymes are highly conserved in the sequence of RBE3. Thus, the branching enzyme isoform belongs to a family of the amylolytic enzymes. RBE3 also shares a noticeable degree of sequence identity with RBE1, especially at the central portion of the protein molecule. However, RBE3 possesses an approximately 70-residue extra sequence at the NH2 terminus and lacks a COOH-terminal sequence of almost 50 residues as compared with RBE1. The structural differences at both termini may explain the distinct role in starch synthesis for RBE1 and RBE3.
• ANTISENSE REGULATION OF THE RICE WAXY GENE-EXPRESSION USING A PCR-AMPLIFIED FRAGMENT OF THE RICE GENOME REDUCES THE AMYLOSE CONTENT IN GRAIN STARCH

  H SHIMADA; Y TADA; T KAWASAKI; T FUJIMURA

  THEORETICAL AND APPLIED GENETICS SPRINGER VERLAG 86 (6) 665 - 672 0040-5752 1993/07 [Refereed]
   

  The waxy gene encodes a granule-bound starch synthase. A 1.0-kb portion of the sequence of the rice waxy gene, which includes the region between exon 4 and exon 9, was inserted in an antisense orientation between the 35 S promoter and the GUS gene of pBI221. The resultant plasmid, pWXA23, was introduced into rice protoplasts by electroporation. GUS activity was clearly detected in derived callus lines, suggesting that the antisense component of the fusion gene was also expressed. Transgenic rice plants were regenerated from these callus lines and their GUS activity was confirmed. Some of the rice seeds from these transformants showed a significant reduction in the amylose content of grain starch, even though they had become polyploid. These results suggest that even when intron sequences are included, antisense constructs can bring about a reduced level of expression of a target gene. The utility of GUS, included as a reporter gene, for the simple detection of expression of an antisense gene, was apparent from these results.
• THE GENE ENCODING A CALCIUM-DEPENDENT PROTEIN-KINASE LOCATED NEAR THE SBE1 GENE ENCODING STARCH BRANCHING ENZYME-I IS SPECIFICALLY EXPRESSED IN DEVELOPING RICE SEEDS

  T KAWASAKI; N HAYASHIDA; T BABA; K SHINOZAKI; H SHIMADA

  GENE ELSEVIER SCIENCE BV 129 (2) 183 - 189 0378-1119 1993/07 [Refereed]
   

  A gene (spk) encoding a Ca2+-dependent protein kinase (SPK) is located in the region immediately upstream of the sbe1 gene encoding a starch branching enzyme. The spk gene is specifically expressed in developing seeds and its expression pattern is very similar to those of genes encoding starch-synthesizing enzymes such as sbe1 and waxy, seed lipid-synthesizing enzymes, as well as genes encoding seed storage proteins. A full-length spk cDNA was isolated from a cDNA library constructed from developing seeds. The deduced amino acid sequence showed that SPK has a high degree of homology to soybean and carrot Ca2+-dependent protein kinase, both of which contain calmodulin domains. The calmodulin domain, as well as the catalytic subdomain consensus regions of protein kinases are highly conserved in SPK. These results suggest that a tissue- and stage-specific protein kinase, SPK, is involved in the synthesis of seed storage compounds during seed development. They also strongly suggest that Ca2+ is required for seed development.
• MOLECULAR ANALYSIS OF THE GENE ENCODING A RICE STARCH BRANCHING ENZYME

  T KAWASAKI; K MIZUNO; T BABA; H SHIMADA

  MOLECULAR & GENERAL GENETICS SPRINGER VERLAG 237 (1-2) 10 - 16 0026-8925 1993/02 [Refereed]
   

  The sequence of a rice gene encoding a starch branching enzyme (sbe1) shows extreme divergence from that of the rice gene, that is homologous to.bacterial glycogen branching enzyme (sbe2). sbe1 is expressed abundantly and specifically in developing seeds and maximally in the middle stages of seed development. This expression pattern completely coincides with that of the waxy gene, which encodes a granule-bound starch synthase. Three G-box motifs and consensus promoter sequences are present in the 5' flanking region of sbe1. It encodes a putative transit peptide, which is required for transport into the amyloplast. A 2.2 kb intron (intron 2) precedes the border between the regions encoding the transit peptide and the mature protein, and contains a high G/C content with several repeated sequences in its 5' half. Although only a single copy of sbe1 is present in the rice genome, Southern analysis using intron 2 as a probe indicates the presence of several homologous sequences in the rice genome, suggesting that this large intron and also the transit peptide coding region may be acquired from another portion of the genome by duplication and insertion of the sequence into the gene.
• CDNA SEQUENCE AND EXPRESSION OF A PHOSPHOENOLPYRUVATE CARBOXYLASE GENE FROM SOYBEAN

  T SUGIMOTO; T KAWASAKI; T KATO; RF WHITTIER; D SHIBATA; Y KAWAMURA

  PLANT MOLECULAR BIOLOGY KLUWER ACADEMIC PUBL 20 (4) 743 - 747 0167-4412 1992/11 [Refereed]
   

  A full-length cDNA encoding a subunit of phosphoenolpyruvate carboxylase (PEPC) was isolated from a developing seed expression library of the C3 Plant Glycine max. The corresponding mRNA is present at similar levels in leaf, stem, root and developing seed. Two potential start codons exist, and the activity of protein initiated from the first such codon could be subject to regulation by protein kinase. Sequence comparison shows a similar upstream start codon in the case of the Ppc2 gene from Mesembryanthemum crystallinum, previously assumed to lack the sequences necessary for phosphorylation. The soybean encoded protein tends to resemble other 'C3-type' PEPC proteins more closely than those implicated in C4 or crassulacean acid metabolism.
• STARCH BRANCHING ENZYMES FROM IMMATURE RICE SEEDS

  K MIZUNO; K KIMURA; Y ARAI; T KAWASAKI; H SHIMADA; T BABA

  JOURNAL OF BIOCHEMISTRY JAPANESE BIOCHEMICAL SOC 112 (5) 643 - 651 0021-924X 1992/11 [Refereed]
   

  Four forms of branching enzyme, termed RBE1, RBE2 (a mixture of RBE2A and RBE2B), RBE3, and RBE4, were apparently separated by DEAE-cellulose column chromatography of soluble extract from immature rice seeds, and each of these four forms was further purified by gel-filtration. RBE1, RBE2A, and RBE2B were the predominant forms of the enzyme. The molecular size, amino-terminal amino acid sequence, and immunoreactivity with anti-maize branching enzyme-I (BE-I) antibody were identical among these three forms, except that the molecular mass of RBE2A was almost 3 kDa higher than those of RBE1 and RBE2B. These results indicate that RBE1, RBE2A, and RBE2B are the same (termed rice BE-I). The cDNA clones coding for rice BE-I have been identified from a rice seed library in lambdagt11, using the maize BE-I cDNA as a probe. The nucleotide sequence indicates that rice BE-I is initially synthesized as an 820-residue precursor protein, including a putative 64- or 66-residue transit peptide at the amino terminus. The rice mature BE-I contains 756 (or 754) amino acids with a calculated molecular mass of 86,734 (or 86,502) Da, and shares a high degree of sequence identity (86%) with the maize protein. The consensus sequences of the four regions that form the catalytic sites of amylolytic enzymes are conserved in the central region of the rice BE-I sequence. Thus, rice BE-I as well as the maize protein belongs to a family of amylolytic enzymes.

Books etc

• 植物の自然免疫研究の最前線

  吉久采花; 嶋田啓太; 吉村智美; 山口公志; 川崎努 (Joint work)化学と生物 2020/06
• Rice Genomics, Genetics and Breeding, Pathogen recognition and immune signaling

  KAWASAKI Tsutomu (Joint work)Springer Nature 2018/02
• 植物学の百科事典、植物の病害防除機構

  川崎 努 丸善 2016
• バイオサイエンスとインダストリー、耐病性を向上させた次世代イネの作出に向けて

  山口公志; 川崎 努 2015
• 化学と生物、外界との接点としての細胞壁

  光増可奈子; 川崎 努; 澤進一郎 2015
• 領域融合レビュー、植物における免疫誘導と病原微生物の感染戦略

  川崎 努 2013
• Advances in Genetics, Genomics and Control of Rice Blast Disease, Rac GTPase and the regulation of NADPH oxidase in rice innate immunity.

  川﨑 努; Hann Ling Wong Ko Shimamoto (Joint work)2008
• モデル植物実験プロトコール

  川崎 努 秀潤社 2005
• 植物細胞工学シリーズ、分子レベルからみた植物の耐病性

  川崎 努 秀潤社 2004
• 「イネゲノム配列解読で何ができるか」, 「イネゲノム配列解読で何ができるか」

  川﨑 努; 矢野昌裕; 松 (Joint work)農山漁村文化協会 2003
• モデル植物ラボマニュアル

  川崎 努 シュプリンガー 2000
• 植物の化学調節、植物の病気と細胞死

  川崎 努; 島本功 2000
• 植物細胞工学シリーズ 植物の細胞分裂

  川崎 努 秀潤社 2000
• 植物分子生理学入門

  川崎 努 学会出版センター 1999
• 植物のPCR実験プロトコール

  川崎 努 秀潤社 1997

Conference Activities & Talks

• MAPキナーゼとPBIファミリーを介したイネ免疫制御機構の解析  [Not invited]

  一丸 航太; 繁田 修佑; 原田 健一; 児嶋 長次郎; 山口 公志; 吉村 智美; 川崎 努

  日本植物病理学会大会  2019/09
• A Xanthomonas effector suppresses host immunity possibly by inhibiting dimerization of host factor.  [Not invited]

  Koji Yamaguchi; Gohta Yamamoto; Yoshimura Satomi; Seiji Tsuge; Tsutomu Kawasaki

  IS-MPMI XVIII Congress  2019/07
• NB-LRR型受容体Xa1による白葉枯病菌TALエフェクターの認識と抵抗性の発現  [Not invited]

  吉村 智美; 泉谷 眞帆; 安藤 駿丞; 山口 公志; 川崎 努

  日本植物病理学会大会  2019/03
• イネのパターン誘導免疫を制御するSROファミリーの機能解析  [Not invited]

  中居 由依奈; 繁田 修佑; 一丸 航太; 山口 公志; 吉村 智美; 川崎 努

  日本植物病理学会大会  2019/03
• イネ白葉枯病菌エフェクターXopZによる核内標的因子を介した免疫抑制機構の解析  [Not invited]

  山口公志; 山本剛大; 木村泉貴; 吉村智美; 川崎努

  日本植物病理学会大会  2019/03
• イネ免疫タンパクPBI1によるWRKY45の活性制御機構  [Not invited]

  繁田 修佑; 一丸航太; 原田健一; 井上健人; 安藤駿丞; 吉村智美; 山口公志; 児嶋長次郎; 川崎努

  日本植物生理学会年会  2019/03
• NB-LRR型受容体Xa1によるTALエフェクターの認識機構  [Not invited]

  泉谷眞帆; 安藤駿丞; 大内俊和; 山口公志; 吉村 智美; 川崎 努

  日本植物生理学会年会  2019/03
• シロイヌナズナのMAPKKKのダイマー形成と活性化  [Not invited]

  藤尾佳那子; 山口公志; 亀井美里; 山口祥子; 岡崎将大; 川崎努

  日本植物生理学会年会  2019/03
• 植物免疫におけるMAPKを介したAGO4のエピジェネティック制御  [Not invited]

  中川真哉; 山口公志; 山本剛太; 田中裕也; 山口暢俊; 津田賢一; 川崎努

  日本植物生理学会年会  2019/03
• イネ白葉枯病菌エフェクター XopZ による新規免疫抑制機構の解析  [Not invited]

  山本剛大; 木村泉貴; 吉村智美; 山口公志; 津下誠治; 川崎努

  日本植物生理学会年会  2019/03
• イネPBIファミリーを介した免疫制御機構の解析  [Not invited]

  一丸 航太; 繁田 修佑; 原田 健一; 児嶋 長次郎; 山口 公志; 吉村 智美; 川崎 努

  第90回 日本遺伝学会  2018/09
• イネのパターン誘導免疫に関与する新規因子の同定と機能解析  [Not invited]

  中居 由依奈; 繁田 修佑; 一丸 航太; 山口 公志; 吉村 智美; 川崎 努

  第90回 日本遺伝学会  2018/09
• Immune signaling pathways activated by OsCERK1-mediated PAMP recognition  [Invited]

  KAWASAKI Tsutomu

  16th International Symposium on Rice Functional Genomics  2018/09
• The immune responses mediated by Xa1, the NB-LRR receptor  [Not invited]

  Satomi Yoshimura; Toshiya Ouchi; Shunsuke Andou; Maho Izumitani; Koji Yamaguchi; Tsutomu Kawasaki

  16th International Symposium on Rice Functional Genomics  2018/09
• Identification of rice immune factors targeted by the Xanthomonas oryzae pv. oryzae effector  [Not invited]

  Koji Yamaguchi; Gota Yamamoto; Shintaro Nomura; Satomi Yoshimura; Tsutomu Kawasaki

  16th International Symposium on Rice Functional Genomics  2018/09
• Identification of a novel Xanthomonas oryzae effector to suppress rice immune response  [Not invited]

  Koji Yamaguchi; Kento Yamada; Motoki Iwai; Naoki Horiuchi; Satomi Yoshimura; Seiji Tsuge; Tsutomu Kawasaki

  日本植物生理学会年会  2018/03
• イネのキチン応答におけるOsPBI1-OsWRKY45を介した転写制御機構  [Not invited]

  繁田 修佑; 安藤駿丞; 井上健人; 原田健一; 一丸航太; 吉村智美; 山口公志; 児嶋長次郎; 川崎努

  日本植物病理学会関西部会  2018/03
• Molecular mechanism of OsMAPKKK18 activation in rice immunity  [Not invited]

  Akira Terauchi; Kenta Yamada; Koji Yamaguchi; Satomi Yoshimura; Tsutomu Kawasaki

  日本分子生物学会年会  2017/12
• Crosstalk of pattern-recognition receptor-mediated signaling in plant immunity  [Not invited]

  Yuka Kobayashi; Yuina Nakai; Tomomi Shirakawa; Kenta Yamada; Koji Yamaguchi; Tsutomu Kawasaki

  日本分子生物学会年会  2017/12
• 植物免疫プライミング機構におけるMAPKの役割の解析  [Not invited]

  中川真哉; 山本剛太; 津田賢一; 山口公志; 川崎努

  日本植物病理学会関西部会  2017/09
• イネ病原菌認識受容体Xa1によるTALエフェクターの認識機構の解明  [Not invited]

  安藤駿丞; 大内俊和; 泉谷眞帆; 山口公志; 吉村智美; 川﨑努

  日本植物病理学会関西部会  2017/09
• flg22に応答したMAPキナーゼの活性化を制御するMAPKKKの同定  [Not invited]

  山口公志; 小林友華; 深溝慶 川崎努

  日本植物病理学会  2017/04
• Antagonistic regulation of pattern-recognition receptor-mediated signaling in plant immunity  [Not invited]

  Yuka Kobayashi; Tomomi Shirakawa; Kenta Yamada; Saori Suizu; Hitomi Tagawa; Koji Yamaguchi; Tsutomu Kawasaki

  日本植物生理学会年会  2017/03
• Conservation of chitin-induced MAPK activation mechanisms between rice and Arabidopsis  [Not invited]

  Kenta Yamada; Koji Yamaguchi; Akira Terauchi; Satomi Yoshimura; Tsutomu Kawasaki

  日本植物生理学会  2017/03
• Battle between rice immune system and Xanthomonas oryzae effectors  [Not invited]

  Koji Yamaguchi; Tsutomu Kawasaki

  日本植物生理学会  2017/03
• The CERK1-associated kinase PBL27 regulates chitin-triggered MAPK activation through phosphorylation of MAPKKK5 in Arabidopsis  [Not invited]

  Koji Yamaguchi; Kenta Yamada; Tomomi Shirakawa; Akira Mine; Yuka Kobayashi; Masayuki Fujiwara; Kazuya Ichimura; Mari Narusaka; Yoshihiro Narusaka; Kenichi Tsuda; Tsutomu Kawasaki

  Cold Spring Harbor Asia Conference  2016/11
• Conservation of chitin-induced MAPK activation mechanisms between rice and Arabidopsis  [Not invited]

  Kenta Yamada; Koji Yamaguchi; Akira Terauchi; Kazuya Ishikawa; Tsutomu Kawasaki

  IS-MPMI XVII Congress  2016/07
• Biological functions of rice immune factors targeted by Xanthomonas oryzae effectors  [Invited]

  KAWASAKI Tsutomu

  IS-MPMI XVII Congress  2016/07
• PBL27 directly connects between the chitin receptor, CERK1 and MAPK cascade in chitin-triggered immunity.  [Not invited]

  Koji Yamaguchi; Kenta Yamada; Tomomi Shirakawa; Akira Mine; Mari Narusaka; Yoshihiro Narusaka; Kazuya Ichimura; Kenichi Tsuda; Fukamizo Tamo; Naoto Shibuya; Tsutomu Kawasaki

  IS-MPMI XVII Congress  2016/07
• Pathogen recognition and intracellular immune signaling in plants  [Invited]

  KAWASAKI Tsutomu

  International symposium Current and Future Trends in Food and Agricultural Immunology  2016/07
• OsPUB44を介したイネの免疫応答におけるPBI1の機能解析  [Not invited]

  井上健人; 石川和也; 山口公志; 吉村智美; 田中幹人; 原田健一; 児嶋長次郎; 川崎努

  日本植物病理学会大会  2016/03
• 細胞膜上のPBL27とMAPKKK5の相互作用を介したキチン信号伝達機構  [Not invited]

  白川 友美; 山口 公志; 山田 健太; 市村 和也; 深溝 慶; 川﨑 努

  日本植物病理学会大会  2016/03
• キチン受容体複合体の構成因子PUB12によるキチンシグナル伝達の制御機構の解析  [Not invited]

  目崎 博久; 山口 公志; 林 晃大; 三桝 信弥; 藤原 正幸; 深溝 慶; 渋谷直人; 川崎 努

  日本植物病理学会大会  2016/03
• キチン信号伝達系におけるMAPKKK5の活性化機構の解析  [Not invited]

  亀井 美里; 山田 健太; 山口 公志; 白川 友美; 深溝 慶; 川崎 努

  日本植物病理学会  2016/03
• キチン信号伝達系におけるCERK1- PBL27- MAPKKK5のリン酸化リレーの解明  [Not invited]

  山田 健太; 山口 公志; 白川 友美; 中神 弘史; 藤原 正幸; 市村 和也; 深溝 慶; 渋谷 直人; 川崎 努

  日本植物病理学会  2016/03
• MAPKKK5 regulates activation of MAP kinases after perception of fungal chitin in Arabidopsis  [Not invited]

  Koji Yamaguchi; Kenta Yamada; Tomomi Shirakawa; Akira Mine; Mari Narusaka; Yoshihiro Narusaka; Kazuya Ichimura; Kenichi Tsuda; Fukamizo Tamo; Naoto Shibuya; Tsutomu Kawasaki

  日本植物生理学会  2016/03
• PBL27 directly phosphorylates MAPKKK5 to regulate activation of MAPK in chitin signaling  [Not invited]

  Kenta Yamada; Koji Yamaguchi; Tomomi Shirakawa; Hirofumi Nakagami; Masayuki Fujiwara; Kazuya Ichimura; Tamo Fukamizo; Naoto Shibuya; Tsutomu Kawasaki

  日本植物生理学会  2016/03
• Molecular basis of the intracellular MAPK activation induced by perception of fungal chitin in Arabidopsis  [Not invited]

  Tsutomu Kawasaki; Koji Yamaguchi

  日本植物生理学会  2016/03
• エフェクターの宿主標的因子を利用した植物免疫シグナル伝達経路の解析  [Not invited]

  山口公志; 山田健太; 白川友美; 川崎努

  植物感染生理談話会  2015/08
• XopP, a type III effector of Xanthomonas oryzae, suppresses plant immunity via modulation of OsPUB44 ubiquitin ligase activity  [Not invited]

  Kazuya Ishikawa; Kenta Inoue; Koji Yamaguchi; Kazuaki Sakamoto; Yuichiro Muraguchi; Shiori Kitano; Madoka Ogawa; Seiji Tsuge; Tsutomu Kawasaki

  The 4th International Conference on Biotic Plant Interactions  2015/08
• Molecular basis of OsRLCK185-mediated activation of MAP kinase cascade in chitin singnaling in rice  [Not invited]

  Kenta Yamada; Koji Yamaguchi; Tsutomu Kawasaki

  The 4th International Conference on Biotic Plant Interaction  2015/08
• PBL27 directly phosphorylates MAPKKK to activate chitin-induced MAPK cascade in Arabidopsis  [Not invited]

  Koji Yamaguchi; Kenta Yamadaa; Tomomi Shirakawa; Yuka Kobayashi; Misato Kamei; Tsutomu Kawasaki

  The 4th International Conference on Biotic Plant Interaction  2015/08
• Antagonistic regulation of MAP kinase cascades in PRRs-mediated immunity.  [Not invited]

  Koji Yamaguchi; Kenta Yamada; Tomomi Shirakawa; Yuka Kobayashi; Misato Kamei; Tsutomu Kawasaki

  The 26th International Conference on Arabidopsis Research  2015/07
• キチン信号伝達系におけるMAPKKKの活性化の遺伝学的解析  [Not invited]

  白川 友美; 山口 公志; 山田 健太; 市村 和也; 藤原 正幸; 深溝 慶; 川崎 努

  日本植物病理学会  2015/03
• PBL27はMAPKKKをリン酸化することでCERK1によるシグナルをMAPKカスケードへ伝達する  [Not invited]

  山田 健太; 山口 公志; 白川 友美; 石川 和也; 鳴坂 真理; 鳴坂 義弘; 市村 和也; 深溝 慶; 渋谷 直人; 川崎 努

  日本植物病理学会  2015/03
• イネの免疫応答におけるOsPUB44 interactor1 (PBI1)の機能解析  [Not invited]

  井上健人; 石川和也; 山口公志; 吉村智美; 川﨑努

  日本植物病理学会  2015/03
• 免疫応答におけるAtPUB28の機能解析  [Not invited]

  石川和也; 田中幹人; 山川結; 宮腰篤; 山口貴子; 山口公志; 川崎努

  日本植物病理学会  2015/03
• PBL27 directly phosphorylates MAPKKK to activate MAPK cascade in chitin response  [Not invited]

  山田 健太; 山口 公志; 白川 友美; 石川 和也; 市村和也; 深溝 慶; 渋谷 直人; 川崎 努

  日本植物生理学会  2015/03
• イネの免疫応答を正に制御するOsPUB44の相互作用因子の同定  [Not invited]

  石川和也; 井上健人; 山口公志; 吉村智美; 村口由一郎; 北野詩織; 小川まどか; 川崎努

  日本植物生理学会  2015/03
• Identification of Immune factors Interacted with Xa1, the Bacterial Blight Resistance BED-NB-LRR Protein in Rice.  [Not invited]

  早田奈央; 吉村智美; 大内俊和; 井戸悠太; 川崎努

  日本植物生理学会  2015/03
• PBL27はMAPKKKaを介してキチンに応答したMAPキナーゼの活性化を制御する  [Not invited]

  山口公志; 山田健太; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 渋谷直人; 川崎努

  日本植物生理学会  2015/03
• Xanthomonasエフェクターによる宿主のユビキチン修飾系の制御  [Not invited]

  石川和也; 井上健人; 山口公志; 川崎努

  植物細菌病談話会  2014/10
• MAPKKKaはキチンに応答したMAPキナーゼの活性化を制御する  [Not invited]

  山口公志; 山田健太; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 川﨑努

  日本植物病理学会関西部会  2014/09
• イネの免疫応答を正に制御するOsPUB44の相互作用因子の解析  [Not invited]

  井上健人; 石川和也; 山口公志; 吉村智美; 川﨑努

  農芸化学学会関西支部会  2014/09
• 植物免疫におけるMAPKKKの活性化機構の解析  [Not invited]

  白川友美; 山口公志; 山田健太; 市村和也; 深溝慶; 川﨑努

  農芸化学学会関西支部会  2014/09
• XopP, a type III effector of Xanthomonas oryzae, suppresses plant immunity via modulation of host ubiquitin ligase activity  [Not invited]

  Kazuya Ishikawa; Kento Inoue; Koji Yamaguchi; Kazuaki Sakamoto; Yuichiro Muraguchi; Shiori Kitano; Madoka Ogawa; Seiji Tsuge; Tsutomu Kawasaki

  XVI International Congress of Molecular Plant-Microbe Interactions  2014/07
• Identification of immune factors interacted with xa1, the bacterial blight resistance NB-LRR protein in rice  [Not invited]

  Satomi Yoshimura; Nao Hayata; Yuta Ido; Tsutomu Kawasaki

  XVI International Congress of Molecular Plant-Microbe Interactions  2014/07
• PBL27 functions as a MAPKKK kinase in chitin-induced immune signaling in Arabidopsis  [Not invited]

  Tsutomu Kawasaki; Kenta Yamada; Tomomi Shirakawa; Kouhei Yamauchii; Kazuya Ishikawa; Mari Narusaka; Yoshihiro Narusaka; Mari Nomoto; Kazuya Ichimura; Yasuomi Tada; Tamo Fukamizo; Naoto Shibuya; Koji Yamaguchi

  XVI International Congress of Molecular Plant-Microbe Interactions  2014/07
• Biological function of Xanthomonas effectors in suppression of plant immunity  [Invited]

  KAWASAKI Tsutomu

  The 13th International Conference on Plant Pathogenic Bacteria  2014/06
• イネの免疫応答におけるOsPUB44の機能解析  [Not invited]

  石川和也; 井上健人; 山口公志; 吉村智美; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努

  日本植物病理学会  2014/06
• AtRLCK1によるMAPKKKaを介したキチン認識時のMAPキナーゼの活性化機構の解析  [Not invited]

  山口公志; 山田健太; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 川﨑努

  日本植物病理学会  2014/06
• Suppression of pattern recognition receptor-mediated plant immunity by bacterial effector  [Invited]

  川崎 努

  日本細菌学会  2014/03
• AtRLCK1 functions as a MAPKKK kinase in chitin-induced immune signaling  [Not invited]

  山田健太; 山口公志; 山内康平; 石川和也; 野元美佳; 市村和也; 多田安臣; 深溝 慶; 川崎努

  日本植物生理学会  2014/03
• Identification of immune factors interacted with xa1, the bacterial blight resistance NB-LRR protein in rice.  [Not invited]

  早田奈央; 吉村智美; 井戸悠太; 川﨑努

  日本植物生理学会  2014/03
• 植物免疫におけるAnamorsinの機能解明  [Not invited]

  吉村悠矢; 山口公志; 清瀬嵩人; 吉村智美; 川﨑努

  日本植物生理学会  2014/03
• OsPUB44はイネの免疫応答を正に制御する  [Not invited]

  石川和也; 山口公志; 井上健人; 吉村智美; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努

  日本植物生理学会  2014/03
• AtRLCK1はMAPKKKaを介してキチンに応答したMAPキナーゼの活性化を制御する  [Not invited]

  山口公志; 山田健太; 白川友美; 船間亮汰; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 渋谷直人; 川崎努

  日本植物生理学会  2014/03
• 植物免疫におけるMAPキナーゼカスケードへのシグナル伝達機構の解明  [Not invited]

  山田健太; 山口公志; 石川和也; 吉村悠矢; 杉下亮丞; 加星(岸)光子; 高橋章; 内橋幸平; 多田安臣; 市村和也; 川崎 努

  近畿植物学会  2013/12
• 植物免疫におけるAnamorsinの機能解明  [Not invited]

  吉村悠矢; 山口公志; 清瀬嵩人; 川崎努

  近畿植物学会  2013/12
• 植物免疫におけるOsPUB44の機能解析  [Not invited]

  石川和也; 山口公志; 井上健人; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努

  日本植物病理学会関西部会  2013/09
• 植物の病原菌認識受容体における免疫反応の誘導機構  [Invited]

  川崎 努

  日本生体防御学会  2013/07
• Xoo3222, type III effector, targets OsPUB44, a regulator of PAMPs-induced basal resistance  [Not invited]

  Kazuya Ishikawa; Koji Yamaguchi; Kazuaki Sakamoto; Yuichiro Muraguchi; Seiji Tsuge; Chojiro Kojima; Tsutomu KawasakiTsutomu

  KEYSTONE SYMPOSIA  2013/04
• OsCERK1を介したキチン信号伝達系におけるOsRLCK2の機能の解明  [Not invited]

  山田健太; 山口公志; 石川和也; 吉村悠矢; 杉下亮丞; 加星(岸)光子; 高橋章; 内橋幸平; 多田安臣; 市村和也; 川崎 努

  日本植物病理学会  2013/03
• ユビキチンリガーゼであるOsPUB44の植物免疫における機能解析  [Not invited]

  石川和也; 山口公志; 吉村智美; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努

  日本植物病理学会  2013/03
• イネとシロイヌナズナで保存されたキチンシグナル伝達経路の解析  [Not invited]

  山口公志; 新屋友規; 船間亮汰; 石川和也; 山田健太; 鳴坂真理; 鳴坂義弘; 多田安臣; 市村和也; 渋谷直人; 川崎努

  日本植物病理学会  2013/03
• OsRLCK2はOsCERK1に依存したMAPキナーゼの活性化を制御する  [Not invited]

  山口公志; 石川和也; 山田健太; 石濱信明; 濱田聡; 津下誠治; 島本功; 吉岡博文; 川崎努

  日本植物生理学会  2013/03
• 植物免疫におけるOsPUB44の機能とXoo3222による阻害機構  [Not invited]

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 児嶋長次郎; 川崎努

  日本植物生理学会  2013/03
• エフェクターによるイネ免疫信号伝達系の抑制機構  [Invited]

  川崎努; 山口公志; 石川和也; 山田健太; 吉村悠矢

  日本植物生理学会・シンポジウム  2013/03
• 病原菌の感染から身を守る植物の免疫機構  [Not invited]

  川崎 努

  アグリバイオシンポジウム  2012/12
• 植物と病原菌の分子レベルの戦い  [Not invited]

  川崎 努

  第12回けいはんな地区植物科学懇談会  2012/11
• 植物の免疫と病原菌の感染戦略  [Not invited]

  川崎 努

  近畿植物学会講演会  2012/11
• 植物免疫におけるOsPUB44の機能およびTypeⅢエフェクターによる認識機構の解明  [Not invited]

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努

  日本植物病理学会関西部会  2012/09
• 植物免疫におけるAnamorsinの機能解明  [Not invited]

  吉村悠矢; 山口公志; 石川和也; 川崎努

  植物感染生理談話会  2012/08
• 病原菌エフェクターによる新奇の植物免疫阻害機構の解明  [Not invited]

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努

  植物感染生理談話会  2012/08
• イネにおけるPAMPs誘導抵抗性の情報伝達機構と病原菌の感染戦略  [Invited]

  川崎努; 山口公志; 石川和也; 吉村智美; 山田健太; 吉村悠矢

  植物感染生理談話会  2012/08
• キチン認識受容体OsCERK1の相互作用因子OsRLCK2を介したMAPキナーゼ活性化機構の解明  [Not invited]

  山口公志; 山田健太; 石川和也; 加星(岸)光子; 高橋章; 林長生; 市村和也; 島本功; 吉岡博文; 川崎努

  日本植物分子細胞学会  2012/08
• OsPUB44, a regulator of PAMPs-induced basal resistance, is targeted by type III effector Xoo3222  [Not invited]

  Kazuya Ishikawa; Koji Yamaguchi; Kazuaki Sakamoto; Yuichiro Muraguchi; Seiji Tsuge; Ko Shimamoto; Chojiro Kojima; Tsutomu Kawasaki

  XV International Congress of Molecular Plant-Microbe Interactions Kyoto  2012/07
• OsBPC1 targeted by Xoo1488 effector regulates chitin induced immunity in rice  [Not invited]

  Yamaguchi, K; Masutani, I; Ishikawa; Kawasaki, T

  XV International Congress of Molecular Plant-Microbe Interactions Kyoto  2012/07
• OsRLCK2 targeted by Xanthomonas Xoo1488 effector regulates MAP kinase cascade activated by OsCERK1-mediated recognition of chitin in rice  [Not invited]

  Yamaguchi, K; Yamada, K; Ishikawa, K; Tsuge, S; Ichimura, K; Yoshioka, H; Shimamoto, K; Kawasaki, T

  XV International Congress of Molecular Plant-Microbe Interactions Kyoto  2012/07
• OsPUB44, a regulator of PAMPs-induced basal resistance, is targeted by Xanthomonas type III effector Xoo3222  [Not invited]

  Ishikawa, K; Yamaguchi, K; Sakamoto, K; Muraguchi, Y; Tsuge, S; Shimamoto, K; Kojima, C; Kawasaki, T

  The Biology of Plant, 77th symposium of Cold Spring Harbor Laboratory  2012/05
• OsRLCK2 targeted by Xanthomonas Xoo1488 effector regulates MAP kinase cascade activated by OsCERK1-mediated recognition of chitin in rice  [Not invited]

  Kawasaki, T; Yamaguchi, K; Yamada, K; Ishikawa, K; Tsuge, S; Shimamoto, K; Ichimura, K; Yoshioka, H

  The Biology of Plant, 77th symposium of Cold Spring Harbor Laboratory  2012/05
• 植物免疫におけるOsPUB44の機能と病原菌エフェクターによる阻害機構  [Not invited]

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努

  日本植物病理学会  2012/03
• 病原菌エフェクターの標的であるOsRLCKを介したキチンシグナル伝達機構の解明  [Not invited]

  山口公志; 石川和也; 山田健太; 石濱信明; 濱田聡; 津下誠治; 島本功; 吉岡博文; 川崎努

  日本植物病理学会  2012/03
• 病原菌エフェクターの標的であるOsRLCKを介したキチンシグナル伝達機構の解明  [Not invited]

  山口公志; 石川和也; 山田健太; 石濱信明; 濱田聡; 津下誠治; 島本功; 吉岡博文; 川崎努

  日本植物生理学会  2012/03
• 植物免疫におけるOsPUB44の機能とTypeⅢエフェクターXoo3222による阻害機構  [Not invited]

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努

  日本植物生理学会  2012/03
• いもち病に対する抵抗性タンパク質Piaの機能解析  [Not invited]

  藤原幹; 河野洋治; 寺内良平; 川崎努; 島本功

  植物病理学会関西部会  2011/10
• GEFを介したMAMPによるOsRac1活性化メカニズムの解析  [Not invited]

  赤松明; H.L. Wong; 奥田 淳; 西出啓太; 今井圭子; 河野洋治; 渋谷直人; 川崎努; 島本功

  植物病理学会関西部会  2011/10
• イネ白葉枯病菌エフェクターXopPの標的因子の同定および機能解析  [Not invited]

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 児嶋長次郎; 川崎努

  植物病理学会関西部会  2011/10
• イネ白葉枯病菌エフェクターの新奇標的因子OsRLCK2の解析  [Not invited]

  山口公志; 石川和也; 石濱信明; 古谷綾子; 落合弘和; 津下誠治; 島本功; 吉岡博文; 川崎努

  植物病理学会関西部会  2011/10
• イネ白葉枯病菌エフェクターXopPの標的因子の機能解析  [Not invited]

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努

  日本植物病理学会  2011/03
• イネ白葉枯病菌エフェクターが標的とするOsRLCKの解析  [Not invited]

  山口公志; 石川和也; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努

  日本植物病理学会  2011/03
• イネ白葉枯病菌エフェクターXopPの標的因子の同定  [Not invited]

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努

  日本植物生理学会年会  2011/03
• 白葉枯病菌エフェクターの標的因子の同定とその解析  [Not invited]

  山口公志; 石川和也; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努

  日本植物生理学会年会  2011/03
• Mechanism of OsRac1 activation in Pi-a-mediated disease resistance  [Not invited]

  藤原幹; 川﨑 努; 河野 洋治; 島本 功

  BMB2010  2010/12  神戸  BMB2010
  
• Analysis of PAMP-induced OsRac1 activation using a FRET biosensor in rice.  [Not invited]

  赤松 明; 川﨑 努; Hann Ling Won; 奥田; 淳; 西出; 圭太; 今井; 圭子; 河野; 洋治; 渋谷; 直人; 島本 功

  BMB2010  2010/12  神戸  BMB2010
  
• 植物の病原菌認識機構と病原菌の感染戦略  [Invited]

  川﨑 努

  生存圏シンポジウム  2010/11  京都  生存圏シンポジウム
  
• イネ白葉枯病菌エフェクターXopPの標的宿主因子の探索  [Not invited]

  石川 和也; 川﨑 努; 山口 公志; 古谷綾子; 落合弘和; 津下誠治; 島本功

  日本農芸化学会 関西支部会  2010/10  近畿大  日本農芸化学会 関西支部会
  
• イネ白葉枯病菌エフェクターを利用したイネ耐病性機構の解明  [Not invited]

  山口 公志; 川﨑 努; 石川 和也; 古谷綾子; 落合弘和; 津下誠治; 島本功

  日本農芸化学会 関西支部会  2010/10  近畿大  日本農芸化学会 関西支部会
  
• Control of plant immunity by Xanthomonas effectors and GM crop research in Japan  [Invited]

  KAWASAKI Tsutomu

  The ommemorative international symposium for the 50th anniversary of KSABC  2010/08  大韓民国  The ommemorative international symposium for the 50th anniversary of KSABC
  
• イネ白葉枯病菌エフェクターを利用したイネPAMPs誘導抵抗性の解析  [Not invited]

  川﨑 努; 山口 公志; 古谷綾子; 落合弘和; 津下誠治; 島本功

  学会 京都 4月18-20日  2010/04  京都  学会 京都 4月18-20日
  
• Rタンパク質によるGタンパク質OsRac1の活性化が植物 免疫に重要である  [Not invited]

  河野 洋治; 川﨑 努; 林 敬子; 赤松; 明; 宝泉; 雄介; 奥田 淳; 中島綾子; 高橋; 弘喜; 吉田; 均; Hann Ling; WONG 島本 功

  日本植物病理学会  2010/04  京都  日本植物病理学会
  
• Identification of host targets of Xanthomonas oryzae pv. oryzae effectors  [Not invited]

  山口 公志; 川﨑 努; Ayako Furutani; Hirokazu Ochiai Seiji Tsuge Ko Shimamoto

  21st International Conference on Arabidopsis Research  2010  横浜  21st International Conference on Arabidopsis Research
  
• FRETセンサーを用いたイネ低分子量Gタンパク質OsRac1活性化経路の解析  [Not invited]

  赤松 明; 川﨑 努; Hann Ling Won; 奥田; 淳; 西出; 圭太; 今井; 圭子; 河野; 洋治; 渋谷; 直人; 島本 功

  日本植物病理学会  2010  京都  日本植物病理学会
  
• 低分子量GTP結合タンパク質イネOsRac1を介した抵抗性タンパク質による過敏感反応死と耐病性の制御機構  [Not invited]

  河野 洋治; 川﨑 努; 林 敬子; 赤松; 明; 宝泉; 雄介; Pek Chin LOH; 中島; 綾子; 高橋; 弘喜; 吉田; 均; 島本 功

  日本植物生理学会  2009  日本植物生理学会
  
• 病原菌の感染戦略と植物の防御応答  [Not invited]

  川﨑 努

  日本植物病理学会関西地区若手の会  2009  日本植物病理学会関西地区若手の会
  
• Type III effectors of Xanthomonas oryza pv. oryzae suppress PAMPs-triggered immunity in rice  [Not invited]

  川﨑 努; 山口 公志; A. Furutani; H. Ochiai; S. Tsuge; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Activation of RacGTPase-mediated defence signalling by pathogen-associated molecular patterns and guanine nucleotide exchange factor in rice  [Not invited]

  H.L. Wong; 川﨑 努; A. Akamatsu; K. Imai; J; Okuda T; Zhu K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Proteome analysis of lipid rafts associated with rice innate immunity mediated by OsRac1  [Not invited]

  M. Fujiwara; 川﨑 努; S. Hamada; Y. Fukao; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• GAPDH, a novel component of OsRac1-mediated innate immunity in rice  [Not invited]

  J. Su; 川﨑 努; L. Chen; H. Wong; M. Fujiwara; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Analysis of small GTPase OsRac1 activation in rice stably transformed with a FRET biosensor  [Not invited]

  K. Lim; 川﨑 努; A. Akamatsu; H. Wong; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• LAP (bHLH) is a transcription factor activated by OsRac1 in rice innate immunity  [Not invited]

  S. Kim; 川﨑 努; T. Oikawa; J. Kyozuka; H. Wong; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Identification of DH-PH type GDP-GTP exchange factor for Rac/Rop GTPase in plant immune response  [Not invited]

  川﨑 努; K. Yamaguchi; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• OsRap2.6 is a candidate of downstream effector of OsRac1 in rice innate immunity  [Not invited]

  M. J. Wamaitha; 川﨑 努; R. Yamamoto; Y. Kawano; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Serotonin is a novel inducer of immune responses in rice  [Not invited]

  T. Fujiwara; 川﨑 努; S. Maisonneuve; M; Isshiki M. Mizutani; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• The activation of OsRac1 by R protein plays a critical role in innate immune responses in rice  [Not invited]

  Y. Kawano; 川﨑 努; A. Akamatsu; K. Hayashi; Y. Housen; P. C. Loh; A. Nakashima; H. Takahashi; H; Yoshida K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Visualization ofternary complexes involved in innate immunity in living plant cells by using aBiFC-based FRET-FLIM  [Not invited]

  Y. Ishikawa; 川﨑 努; H. Wong; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Hop/Sti1 is required for PAMP receptor biogenesis, transport to the plasma membrane and function in rice innate immunity  [Not invited]

  L. Chen; 川﨑 努; N. Thao; A; Nakashima T. Zhu; H. Kaku; N. Shibuya; P. Krishna; K. Shirasu; K. Umemura; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• Analysis of PAMPs-induced OsRac1 activation using FRET biosensor in rice  [Not invited]

  A. Akamatsu; 川﨑 努; J. Okuda; T. H. L. Wong; K. Shimamoto

  XIV International Congress on Molecular Plant-Microbe Interactions  2009  XIV International Congress on Molecular Plant-Microbe Interactions
  
• イネ白葉枯病菌Type Ⅲエフェクターの機能解析  [Not invited]

  山口公志; 川﨑 努; 古谷綾子; 落合弘和; 津下誠治; 島本功

  日本植物病理学会  2009  日本植物病理学会
  
• 植物免疫信号伝達系におけるセロトニンの機能解析  [Not invited]

  藤原 幹; 川﨑 努; Sylvie Maisonneuve; 一色; 正之; 水谷; 正治; 島本 功

  日本植物生理学会  2009  日本植物生理学会
  
• RACK1 functions in rice innate immunity by interacting with the OsRac1 immune complex  [Not invited]

  Chen, L; 川﨑 努; Nakashima; A. Thao; N.P. Fujiwara; M. Wong; H.L. Shimamoto, K

  Plant Genomics in China  2008  Plant Genomics in China
  
• 植物免疫信号伝達系におけるセロトニンの機能解析  [Not invited]

  藤原 幹; 川﨑 努; Sylvie Maisonneuve; 一色; 正之; 水谷; 正治; 島本 功

  日本分子生物学会年会  2008  日本分子生物学会年会
  
• FRETバイオセンサーを用いた植物細胞における低分子量Gタンパク質の解析  [Not invited]

  赤松 明; 川﨑 努; 河野 洋治; 奥田; 淳; Hann Ling Wong; 島本 功

  日本分子生物学会年会  2008  日本分子生物学会年会
  
• 低分子量GTP結合タンパク質イネOsRac1を介した抵抗性タンパク質による過敏感反応死と耐病性の制御機構  [Not invited]

  河野洋治; 川﨑 努; Pek Chin Loh; 林敬子; 赤松; 明; 中島綾子; 高橋弘喜; 吉田均; 島本功

  日本分子生物学会年会  2008  日本分子生物学会年会
  
• LAP (bHLH) is a transcription factor activated by OsRac1 in rice innate immunity  [Not invited]

  Sung-Hyun Kim; 川﨑 努; Tetsuo Oikawa Junko; Kyozuka Hann Ling; Wong; Ko Shimamoto

  6th International symposium on rice functional genomics  2008  6th International symposium on rice functional genomics
  
• Sti1/Hop, a Hsp90 co-chaperone, is a novel key component of defensome involved in PAMP-mediated innate immunity in rice  [Not invited]

  Chen, L; 川﨑 努; Nakashima; A. Thao; N.P. Fujiwara; M. Wong; H.L. Shimamoto, K

  6th International symposium on rice functional genomics  2008  6th International symposium on rice functional genomics
  
• G protein mediated innate immunity of rice  [Not invited]

  川﨑 努

  UC Riverside workshop  2007  UC Riverside workshop
  
• RacGEFs function as activators of small GTPase OsRac1 in innate immunity of rice  [Not invited]

  Imai, K; 川﨑 努; Wong; H.L. Kawano; Y. Nishide; K. Okuda; J. Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Rac GTPase regulates reactive oxygen production by binding to the N-terminal extension of NADPH oxidase in rice  [Not invited]

  Wong, H.L; 川﨑 努; Pinontoan; R. Hayashi; K. Tabata; R. Yaeno; T. Hasegawa; K. Kojima; C. Yoshioka; H. Iba, K; Kawasaki, T; Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Small GTPase OsRac1 interacts with NBS-LRR resistance proteins  [Not invited]

  Kawano, Y; 川﨑 努; Nakashima; A. Takahashi; H. Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Role of RAR1 and HSP90 in RacGTPase-mediated innate immunity in rice  [Not invited]

  Thao, N.P; 川﨑 努; Chen, L. Hara; S. Umemura; K. Shirasu; K. Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Proteome analysis of lipid rafts: are lipid rafts associated with OsRac1-mediated innate immunity in rice  [Not invited]

  Fujiwara, M; 川﨑 努; Hiratsuka; M. Fukao; Y. Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• STI1/HOP, a HSP90 cochaperon, is a novel component in defense signaling in rice  [Not invited]

  Chen, L; 川﨑 努; Thao; N.P. Nakashima; A Umemura; K. Takahashi; A. Shirasu; K. Shimamoto, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Rac GTPase-mediated innate immunity in rice  [Not invited]

  Shimamoto, K; 川﨑 努; Chen, L. Thao; N.P. Nakashima; A. Kawano; Y. Imai; K. Wong; H.L. Umemura, K

  13th Inernational congress on molecular plant-microbe interactions  2007  13th Inernational congress on molecular plant-microbe interactions
  
• Cytochrome P450 monooxygenase encoded by Sekiguchi-Asahi gene produces serotoni, a novel mediator for defense responses in rice  [Not invited]

  川﨑 努

  International workshop on molecular plant pathology  2007  International workshop on molecular plant pathology
  
• G protein mediated innate immunity of rice  [Not invited]

  川﨑 努

  UC Davis workshop  2007  UC Davis workshop
  
• Gタンパク質を介した病原体認識シグナルの伝達  [Not invited]

  川﨑 努; 島本 功

  植物感染生理談話会  2007  植物感染生理談話会
  
• 植物におけるG蛋白質を介した自然免疫応答  [Not invited]

  川﨑 努

  平成１９年度特定領域「G蛋白質シグナル」公開シンポジウム  2007  平成１９年度特定領域「G蛋白質シグナル」公開シンポジウム
  
• 脂質ラフト領域のプロテオーム解析―イネ耐病性シグナリングにおける脂質ラフトの役割  [Not invited]

  藤原正幸; 川﨑 努; 平塚実里; 深尾陽一朗; 島本功

  日本分子生物学会年会  2007  日本分子生物学会年会
  
• 酵母Two-hybridを用いたイネ耐病性シグナル伝達に関わるRWD相互作用分子の探索  [Not invited]

  山本梨紗; 川﨑 努; 中島綾子; 河野洋治; 島本功

  日本分子生物学会年会  2007  日本分子生物学会年会
  
• イネの病害抵抗性に関わるOsRac1GEFの同定  [Not invited]

  西出圭太; 川﨑 努; 河野洋治; 今井圭子; 島本功

  日本分子生物学会年会  2007  日本分子生物学会年会
  
• FRETバイオセンサーを用いた植物細胞における低分子量Gタンパク質の活性解析  [Not invited]

  奥田淳; 川﨑 努; 松田友徳; Wong; Li

  日本分子生物学会年会  2007  日本分子生物学会年会
  
• イネ耐病性におけるOsRacファミリーの機能解析  [Not invited]

  塩谷健仁; 川﨑 努; Letian Chen 島本功

  日本分子生物学会年会  2007  日本分子生物学会年会
  
• Regulation of reactive oxygen production by binding of Rac GTPase to the N-terminal extension of NADPH oxidase of rice  [Not invited]

  Wong, H.L; 川﨑 努; Pinontoan; R. Hayashi; K. Tabata; R. Yaeno; T. Hasegawa; K. Kojima; C. Yoshioka; H. Iba; K. Shimamoto, K

  The 4th international rice blast conference  2007  The 4th international rice blast conference
  
• Rac GTPase-mediated blast resistance in rice  [Not invited]

  Shimamoto, K; 川﨑 努; Chen, L. Thao; N.P. Nakashima; A. Kawano; Y. Imai; K. Wong; H.L. Umemura, K

  The 4th international rice blast conference  2007  The 4th international rice blast conference
  
• RacGEFs function as activators of small GTPase OsRac1 in innate immunity of rice  [Not invited]

  川﨑 努; Imai; K. Wong; H.L. Kawano; Y. Nishide; K. Okuda; J. Shimamoto, K

  The 4th international rice blast conference  2007  The 4th international rice blast conference
  
• 新規耐病性植物の開発に向けて  [Not invited]

  川﨑 努

  第16回 IISシーズフォーラム  2006  第16回 IISシーズフォーラム
  
• イネ耐病性シグナリングにおける脂質ラフト領域のプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 平塚美里; 島本

  日本植物病理学会大会  2006  日本植物病理学会大会
  
• Gタンパク質を介した病原体認識と信号伝達  [Not invited]

  川﨑 努

  九州大学農学部セミナー  2006  九州大学農学部セミナー
  
• プロテオーム解析によるイネ研究  [Not invited]

  川﨑 努; 藤原正幸; 島

  イネ分子生物ワークショップ  2006  イネ分子生物ワークショップ
  
• 植物の耐病性反応におけるリグニン合成とセロトニン生成の制御  [Not invited]

  川﨑 努

  サントリーセミナー  2006  サントリーセミナー
  
• Proteome analysis of lipid rafts associated with defense signaling of rice.  [Not invited]

  Masayuki Fujiwara; 川﨑 努; Minori Hiratsuka Ko Shimamoto

  20th IUBMB International Congress of Biochemistry and Molecular Biology  2006  20th IUBMB International Congress of Biochemistry and Molecular Biology
  
• Gタンパクを介した植物免疫の新規因子RWD/OsRACK1の機能解析  [Not invited]

  中島綾子; 川﨑 努; 桑野晶喜; 藤原正幸; Wong Hann-Ling; 島本 功

  日本植物生理学会  2006  日本植物生理学会
  
• RWD/OsRACK1 is a novel factor involved in G protein-mediated plant immunity  [Not invited]

  中島綾子; 川﨑 努; 桑野晶喜; 藤原正幸; Wong Hann-Ling; 島本 功

  20th IUBMB International Congress of Biochemistry and Molecular Biology  2006  20th IUBMB International Congress of Biochemistry and Molecular Biology
  
• A cytochrome P450 (CYP71) is responsible of sekiguchi lesion phenotype in rice.  [Not invited]

  Maisonneuve, S; 川﨑 努; Isshiki; M; Shimamoto, K

  8th International Congress on Plant Molecular Biology  2006  8th International Congress on Plant Molecular Biology
  
• Molecular analysis of the defensome protein complex containing RacGTPase which plays a key role in defense signaling of rice.  [Not invited]

  Thao, N.P; 川﨑 努; Chen; L. Nakashima; A. Umemura; K. Takahashi; A Shirasu; K. Shimamoto, K

  8th International Congress on Plant Molecular Biology  2006  8th International Congress on Plant Molecular Biology
  
• Rice small GTPase OsRac1 regulates lignin biosynthesis through regulation of both NADPH oxidase and cinnamoyl-CoA reducates activities  [Not invited]

  川﨑 努; Koita; H. Wakabayashi; K. Hasegawa; K. Nakatsubo; T. Umezawa; T. Umemura; K. Shimamoto, K

  7th International Congress on Molecular Plant-Microbe Interactions  2005  7th International Congress on Molecular Plant-Microbe Interactions
  
• G protein-mediated defense signaling in rice  [Not invited]

  川﨑 努

  7th KRIBB-NAIST-KU Joint Synposium  2005  7th KRIBB-NAIST-KU Joint Synposium
  
• Cloning of Sekiguchi lesion (sl) gene in rice  [Not invited]

  Maisonneuve, S; 川﨑 努; Isshiki; M; Shimamoto, K

  7th International Congress on Molecular Plant-Microbe Interactions  2005  7th International Congress on Molecular Plant-Microbe Interactions
  
• Direct interaction of GTPase OsRac and NADPH oxidase Osrboh in defense signaling of rice.  [Not invited]

  Wong, H.L; 川﨑 努; Pinontoan; R. Hasegawa; K. Yaeno; T. Iba; K. Tabata; R. Hayashi; K. Kojima; C. Shmamoto, K

  7th International Congress on Molecular Plant-Microbe Interactions  2005  7th International Congress on Molecular Plant-Microbe Interactions
  
• Is small GTPase Rac a target of NBS-LRR proteins?  [Not invited]

  Simamoto, K; 川﨑 努; Nakashima; A. Takahashi; H. Thao; N.P. Chen

  7th International Congress on Molecular Plant-Microbe Interactions  2005  7th International Congress on Molecular Plant-Microbe Interactions
  
• Analysis of the OsRac1 protein complex involved in defense signaling of rice  [Not invited]

  Thao, N.P; 川﨑 努; Chen, L. Hara; S. Nakashima; A. Shimamoto, K

  7th International Congress on Molecular Plant-Microbe Interactions  2005  7th International Congress on Molecular Plant-Microbe Interactions
  
• RWD/OsRACK1 is a novel factor involved in G protein-mediated plant immunity  [Not invited]

  中島綾子; 川﨑 努; 桑野昌喜; 藤原正幸; 島本 功

  COE国際シンポジウム  2005  COE国際シンポジウム
  
• Proteomics of Rac GTPase signaling reveals its predominant role in elicitor-induced defense response of cultured rice cells  [Not invited]

  Fujiwara, M; 川﨑 努; Umemura; K. Shimamoto, K

  5th International Rice Genetics Symposium  2005  5th International Rice Genetics Symposium
  
• Molecular and functional dissection of rac gene family in disease resistance of rice  [Not invited]

  Chen, L; 川﨑 努; Togashi; T. Miki; D. Hirai; S. Shimamoto, K

  5th International Rice Genetics Symposium  2005  5th International Rice Genetics Symposium
  
• Molecular signaling in disease resistance of rice  [Not invited]

  Shimamoto, K; 川﨑 努; Nakashima; A. Fujiwara; M. Thao; NP. Chen; L. Wong; H.L. Miki; D. Imai; K. Maisonneuve; S. Takahashi; H. Kawaguchi; Y. Hirai, S

  5th International Rice Genetics Symposium  2005  5th International Rice Genetics Symposium
  
• イネ耐病性シグナリングにおける脂質ラフト領域のプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 平塚美里; 島本

  日本植物生理学会  2005  日本植物生理学会
  
• アフィニティークロマトグラフィーによるOsRac1と相互作用する因子の単離  [Not invited]

  中島綾子; 川﨑 努; 桑野昌喜; 藤原正幸; 島本 功

  日本植物生理学会  2005  日本植物生理学会
  
• Gタンパク質を介したいもち病抵抗性機構の解明とその応用  [Not invited]

  川﨑 努

  ワークショップ「ゲノム情報を基盤としたイネ－いもち病菌相互作用の解析と耐病性機構の解明」  2005  ワークショップ「ゲノム情報を基盤としたイネ－いもち病菌相互作用の解析と耐病性機構の解明」
  
• Pathogen recognition and defense signaling mediated by G-proteins  [Not invited]

  川﨑 努; Ko Shimamoto

  41th PSJ plant-microbe interactions symposium  2005  41th PSJ plant-microbe interactions symposium
  
• イネにおけるGタンパク質を介した耐病性シグナル伝達  [Not invited]

  川﨑 努; 島本 功

  第７回植物オルガネラワークショップ  2005  第７回植物オルガネラワークショップ
  
• 植物耐病性シグナリングのプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 中島綾子; Nguyen; Phuong Thao; 川口裕介; 島本 功

  21世紀COEプログラム合同研究会 フロンティアバイオサイエンスへの展開  2004  21世紀COEプログラム合同研究会 フロンティアバイオサイエンスへの展開
  
• Downregulation of metallothionein, a reactive oxygen scavenger, by the small GTPase OsRac1 in defense signaling of rice.  [Not invited]

  Wong, HL; 川﨑 努; Sakamoto, T; Shimamoto , K

  NIAS-COE/PROBRAIN/TOKUTEI Joint International Symposium  2004  NIAS-COE/PROBRAIN/TOKUTEI Joint International Symposium
  
• Dual role of the small GTPase OsRac1 as an inducer of ROS and a suppressor of ROS scavenger.  [Not invited]

  Wong, H.L; 川﨑 努; Pinontoan; R. Sakamoto; T. Shimamoto , K

  Plant Biology 2004  2004  Plant Biology 2004
  
• Defense signaling in rice  [Not invited]

  川﨑 努; Ko Shimamoto

  40th PSJ plant-microbe interactions symposium  2004  40th PSJ plant-microbe interactions symposium
  
• イネ低分子量Gタンパク質OsRac1を介したリグニン合成系の制御  [Not invited]

  小板久子; 川﨑 努; 若林健一; 長谷川香奈; 中坪朋文; 梅澤俊明; 梅村賢司; 島本功

  日本分子生物学会  2004  日本分子生物学会
  
• Analysis of OsRac1 protein complex involved in defense signaling of rice  [Not invited]

  Thao, N.P; 川﨑 努; Hara; S. Chen; L. Nakashima; A. Umemura; K Takahashi; A. Shirasu; K. Shimamoto, K

  日本分子生物学会  2004  日本分子生物学会
  
• Functional analysis of OsRAR1 in disease resistance of rice  [Not invited]

  Chen, L; 川﨑 努; Thao; N.P. Hara; S. Umemura; K Takahashi; A. Shirasu; K. Shimamoto, K

  日本分子生物学会  2004  日本分子生物学会
  
• イネOsRacファミリーの機能解析  [Not invited]

  富樫貴; 川﨑 努; 三木大介; 伊藤里香; 島本功

  日本分子生物学会  2004  日本分子生物学会
  
• イネ低分子Gタンパク質OsRac1と相互作用するScaffold protein OsRWDの機能解析  [Not invited]

  中島綾子; 川﨑 努; 島本功

  日本分子生物学会  2004  日本分子生物学会
  
• OsRac1を介したイネの耐病性シグナリングのプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 梅村賢司; 島

  日本分子生物学会  2004  日本分子生物学会
  
• イネにおけるGタンパク質を介した抵抗性シグナル伝達  [Not invited]

  川﨑 努; 藤原正幸; 中島綾子; Wong; H.L. Thao; N.G. Chen; L. 富樫貴; 小板久子; 小松毅史; 三橋正憲; 梅村賢司; 島本功

  日本分子生物学会  2004  日本分子生物学会
  
• イネ低分子量Gタンパク質OsRacによる活性酸素シグナルの調節  [Not invited]

  川﨑 努; Pinontoan; R. Wong; H.L; 中島綾子; 司; 島本功

  日本植物病理学会  2004  日本植物病理学会
  
• The small GTPase OsRac1 regulated lignin biosynthesis through regulation of both NADPH oxidase and cinnamoyl-CoA reductase activities  [Not invited]

  川﨑 努; Koita; H. Wakabayashi; K. Hasegawa; K. Nakatsubo; T. Umezawa; T. Umemura; K. Shimamoto, K

  Gordon research conference  2004  Gordon research conference
  
• イネにおける耐病性シグナリングのプロテオミクス  [Not invited]

  藤原正幸; 川﨑 努; 中島綾子; 常塚創; 島本功

  日本植物生理学会  2004  日本植物生理学会
  
• Direct interaction of OsRac1 with NADPH oxidase regulates ROS production in defense signaling of rice  [Not invited]

  Pinontoan, R; 川﨑 努; Yoshioka; H. Shimamoto, K

  日本植物生理学会  2004  日本植物生理学会
  
• イネ耐病性シグナリングにおけるOsRac1によるメタロチオネイン（活性酸素スカベンジャー）の発現抑制  [Not invited]

  Wong, H.L; 川﨑 努; 坂本剛 島本功

  日本植物生理学会  2004  日本植物生理学会
  
• Gタンパク質を介したイネの耐病性信号伝達  [Not invited]

  川﨑 努; Hann Ling Wong Reinhard Pinontoan; 中島綾子; 島本

  植物病理ワークショップ  2004  植物病理ワークショップ
  
• TAP法による植物のGαと相互作用するタンパク質の探索  [Not invited]

  岸山いづみ; 川﨑 努; 島本功

  日本分子生物学会  2003  日本分子生物学会
  
• Gタンパク質を介したイネの耐病性シグナリングのプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 梅村賢司; 島

  日本分子生物学会  2003  日本分子生物学会
  
• イネの耐病性シグナリングにおけるRAR1 / SGT1の機能解析  [Not invited]

  原真一郎; 川﨑 努; 梅村賢司; 島

  日本分子生物学会  2003  日本分子生物学会
  
• 耐病性シグナリングの解析―システムバイオロジーの展開を目指して  [Not invited]

  島本功; 川﨑 努; 藤原正幸; Pino; o; R. Lieberherr; D. Wong; H.L; 中島綾子; 富樫貴; 津田哲寿; 原真一郎; 池側元哉; 岸山いづみ Phuong; T.N. 梅村賢司

  日本分子生物学会  2003  日本分子生物学会
  
• Downregulation of metallothionein, a reactive cxygen species scavenger, by OsRac1 in defense signaling of rice  [Not invited]

  Wong, H.L; 川﨑 努; Sakamoto, T; Shimamoto, K

  7th international congress of plant molecular biology  2003  7th international congress of plant molecular biology
  
• Expression and functional analysis of OsRac gene family in rice  [Not invited]

  Togashi, T; 川﨑 努; Miki; D. Ito, M; Shimamoto, K

  7th international congress of plant molecular biology  2003  7th international congress of plant molecular biology
  
• Use of affinity chromatography and mass spectrometry for the identification of proteins interacting with OsRac1, a key regulator of defense in rice  [Not invited]

  Nakashima, A; 川﨑 努; Shimamoto, K

  7th international congress of plant molecular biology  2003  7th international congress of plant molecular biology
  
• Identification of the effectors of OsRac1 that is a key regulator of defense response in rice  [Not invited]

  川﨑 努; Wakabayashi; K. Hasegawa; K. Ise; R. Shimamoto, K

  7th international congress of plant molecular biology  2003  7th international congress of plant molecular biology
  
• Rac GTPase is a key regulator of defense signaling in rice  [Not invited]

  Shimamoto, K; 川﨑 努; Wong; H.L. Pinontoan; R. Fujiwara; M. Nakashima; A. Suharsono; U. Wakabayashi; K. Togashi; T. Thao, N

  7th international congress of plant molecular biology  2003  7th international congress of plant molecular biology
  
• Downregulation of metallothionein expression by small GTPase OsRac1 potentiates oxidative burst and disease resistance  [Not invited]

  Wong, H.L; 川﨑 努; Sakamoto; T; Shimamoto, K

  3rd international rice blast conference  2002  3rd international rice blast conference
  
• The heterotrimeric G protein α-subunit acts upstream of the small GTPase Rac in disease resistance of ric  [Not invited]

  Suharsono, U; 川﨑 努; Fujiwara; Y. Iwasaki; Y. Satoh; H. Shimamoto, K

  3rd international rice blast conference  2002  3rd international rice blast conference
  
• G protein signaling in disease resistance of rice  [Not invited]

  Shimamoto, K; 川﨑 努; Suharsono; U. Wong; H.L. Lieberherr; D. Umemura; K. Fujiwara, M

  3rd international rice blast conference  2002  3rd international rice blast conference
  
• Role of small GTP-bindingprotein Rac in defense signaling and regulation of metallothionein  [Not invited]

  Wong, H.L; 川﨑 努; Sakamoto; T; Shimamoto, K

  日本分子生物学会  2002  日本分子生物学会
  
• イネCCR遺伝子の耐病性および細胞死における機能解析  [Not invited]

  若林健一; 川﨑 努; 長谷川香奈

  日本分子生物学会  2002  日本分子生物学会
  
• イネ細胞死変異体を用いた耐病性シグナル伝達機構のプロテオーム解析  [Not invited]

  常塚創; 川﨑 努; 藤原正幸; 島

  日本分子生物学会  2002  日本分子生物学会
  
• Gタンパク質を介したイネの耐病性シグナリングのプロテオーム解析  [Not invited]

  藤原正幸; 川﨑 努; 常塚創 島本功

  日本分子生物学会  2002  日本分子生物学会
  
• Gタンパク質による耐病性シグナリング  [Not invited]

  島本功; 川﨑 努; Suharsono; U. Wong; H; L; 藤原正幸; R; 若林健一; 梅村

  日本分子生物学会  2002  日本分子生物学会
  
• Downregulation of metallothionein expression by small GTPase OsRac1 potentiates oxidative burst and disease resistance  [Not invited]

  Wong, H.L; 川﨑 努; 坂本剛 島本功

  日本植物生理学会  2002  日本植物生理学会
  
• イネにおける耐病性シグナル伝達経路のプロテオーム解析  [Not invited]

  井出香; 川﨑 努; 笠原康裕; 島

  日本分子生物学会  2001  日本分子生物学会
  
• The heterotrimeric G protein acts upstream of the small GTPase Rac in defense signaling  [Not invited]

  Suharsono, U; 川﨑 努; Satoh; H. Shimamoto, K

  日本分子生物学会  2001  日本分子生物学会
  
• イネ低分子量Gタンパク質OsRac1と相互作用するOsPFD3の機能解析  [Not invited]

  伊勢良太; 川﨑 努; 長谷川香奈

  日本分子生物学会  2001  日本分子生物学会
  
• RNAiを利用したイネRac遺伝子ファミリーの機能解析  [Not invited]

  伊藤里香; 川﨑 努; 島本功

  日本分子生物学会  2001  日本分子生物学会
  
• RIN2 interacted with an Arabidopsis disease resistance gene, RPM1 encodes RING finger-type ubiquitin ligase  [Not invited]

  川﨑 努; B.F.Holt III J.Nam; D.Boyes; D.Mackey; C.Taylor; J.L.Dangl

  12th International Conference on Arabidopsis Research  2001  12th International Conference on Arabidopsis Research
  
• PBL27, a member of RLCKs, directly transduces immune signal from chitin receptor to MAPK cascade in plant immunity  [Not invited]

  Kenta Yamada; Koji Yamaguchi; Tomomi Shirakawa; Kazuya Ishikawa; Mari Narusaka; Yoshihiro, Narusaka; Kazuya Ichimura; Tamo Fukamizo; Naoto Shibuya; Tsutomu Kawasaki

  The 26th International Conference on Arabidopsis Research

MISC

• Two different immune pathways activated by the NB-LRR type receptor Xa1 regulate bacterial blight resistance in rice.

  吉久采花; 佐藤颯花; 清水元樹; 峯彰; 山口公志; 吉村智美; 川崎努; 川崎努  日本植物病理学会報  88-  (1)  2022
• イネ白葉枯病菌エフェクターXopZによる新規免疫抑制機構の解析

  山本剛大; 木村泉貴; 吉村智美; 山口公志; 津下誠治; 川崎努  日本植物生理学会年会(Web)  60th-  2019
• イネの細胞膜共受容体OsCERK1および受容体型細胞質キナーゼOsRLCK185のキナーゼドメインの結晶構造解析

  原田健一; 山口公志; 山下栄樹; 新家粧子; 中居由依奈; 児玉高志; 藤原敏道; 中川敦史; 川崎努; 児嶋長次郎; 児嶋長次郎  日本分子生物学会年会プログラム・要旨集(Web)  42nd-  2019
• イネのキチン応答におけるPBI1‐OsWRKY45を介した転写制御機構

  繁田修佑; 原田健一; 井上健人; 安藤駿丞; 一丸航太; 吉村智美; 山口公志; 児嶋長次郎; 川崎努  日本植物生理学会年会(Web)  59th-  ROMBUNNO.3aE05  2018
• イネのキチン応答におけるOsPBI1‐OsWRKY45を介した転写制御機構

  繁田修佑; 安藤駿丞; 井上健人; 原田健一; 一丸航太; 吉村智美; 山口公志; 児嶋長次郎; 児嶋長次郎; 川崎努  日本植物病理学会報  84-  (1)  22‐23(J‐STAGE)  2018
• 植物免疫プライミング機構におけるMAPKの役割の解析

  中川真哉; 山本剛大; 津田賢一; 山口公志; 川崎努  日本植物病理学会報  84-  (1)  20(J‐STAGE)  2018
• イネ病原菌認識受容体Xa1によるTALエフェクターの認識機構の解明

  安藤駿丞; 大内俊和; 泉谷眞帆; 山口公志; 吉村智美; 川崎努  日本植物病理学会報  84-  (1)  23(J‐STAGE)  2018
• イネの細胞膜受容体OsCERK1の細胞内ドメインの結晶構造およびその活性化機構

  原田健一; 山口公志; 山下栄樹; 新家粧子; 藤原敏道; 中川敦史; 川崎努; 児嶋長次郎; 児嶋長次郎  日本蛋白質科学会年会プログラム・要旨集  17th-  88  2017/05
• flg22に応答したMAPキナーゼの活性化を制御するMAPKKKの同定

  山口公志; 小林友華; 深溝慶; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2017-  149  2017/04
• 植物免疫におけるパターン認識受容体シグナル間のクロストーク

  小林友華; 白川友美; 山田健太; 中居由依奈; 山口公志; 川崎努  日本生化学会大会(Web)  90th-  ROMBUNNO.3P‐0420 (WEB ONLY)  2017
• イネの免疫応答におけるOsMAPKKK18の活性化機構の解析

  寺内聡; 山田健太; 山口公志; 吉村智美; 川崎努  日本生化学会大会(Web)  90th-  ROMBUNNO.3P‐0419 (WEB ONLY)  2017
• イネの耐病性応答に関与するOsPBI1の結晶構造解析

  原田健一; 山下栄樹; 井上健人; 山口公志; 藤原敏道; 中川敦史; 川崎努; 児嶋長次郎  日本蛋白質科学会年会プログラム・要旨集  16th-  91  2016/05
• OsPUB44を介したイネの免疫応答におけるPBI1の機能解析

  井上健人; 石川和也; 山口公志; 吉村智美; 田中幹人; 原田健一; 児嶋長次郎; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2016-  57  2016/03
• キチン信号伝達系におけるCERK1‐PBL27‐MAPKKK5のリン酸化リレーの解明

  山田健太; 山口公志; 白川友美; 中神弘史; 藤原正幸; 市村和也; 深溝慶; 渋谷直人; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2016-  56  2016/03
• キチン受容体複合体の構成因子PUB12によるキチンシグナル伝達の制御機構の解析

  目崎博久; 山口公志; 林晃大; 三桝信弥; 藤原正幸; 深溝慶; 渋谷直人; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2016-  57  2016/03
• キチン信号伝達系におけるMAPKKK5の活性化機構の解析

  亀井美里; 山田健太; 山口公志; 白川友美; 深溝慶; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2016-  57  2016/03
• 細胞膜上のPBL27とMAPKKK5の相互作用を介したキチン信号伝達機構

  白川友美; 山口公志; 山田健太; 市村和也; 深溝慶; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2016-  56  2016/03
• エフェクターの宿主標的因子を利用した植物免疫シグナル伝達経路の解析

  山口公志; 山田健太; 白川友美; 川崎努  日本植物病理学会植物感染生理談話会論文集  (50)  63‐71  2015/08
• 耐病性を向上させた次世代イネの作出に向けて

  山口公志; 川崎努  バイオサイエンスとインダストリー  73-  (3)  206  -209  2015/05
• 免疫応答におけるAtPUB28の機能解析

  石川和也; 田中幹人; 山川結; 宮腰篤; 山口貴子; 山口公志; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2015-  159  2015/03
• PBL27はMAPKKKをリン酸化することでCERK1によるシグナルをMAPKカスケードへ伝達する

  山田健太; 山口公志; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 渋谷直人; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2015-  94  2015/03
• キチン信号伝達系におけるMAPKKKの活性化の遺伝学的解析

  白川友美; 山口公志; 山田健太; 市村和也; 藤原正幸; 深溝慶; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2015-  93  2015/03
• イネOsRLCK185によるNADPHオキシダーゼのリン酸化活性化機構

  吉岡美樹; 山口公志; 藤原正幸; 吉村智美; 川崎努; 吉岡博文  日本植物病理学会大会プログラム・講演要旨予稿集  2015-  96  2015/03
• イネの免疫応答におけるOsPUB44 interactor1(PBI1)の機能解析

  井上健人; 石川和也; 山口公志; 吉村智美; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2015-  96  2015/03
• MAPKKKaはキチンに応答したMAPキナーゼの活性化を制御する

  山口公志; 山田健太; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 川崎努  日本植物病理学会報  81-  (1)  66‐67  2015
• イネの免疫応答を正に制御するOsPUB44の相互作用因子の解析

  井上健人; 石川和也; 山口公志; 吉村智美; 川崎努  日本農芸化学会関西支部講演会講演要旨集  486th-  57  2014/09
• 植物免疫におけるMAPKKKの活性化機構の解析

  白川友美; 山口公志; 山田健太; 市村和也; 深溝慶; 川崎努  日本農芸化学会関西支部講演会講演要旨集  486th-  56  2014/09
• イネの免疫応答におけるOsPUB44の機能解析

  石川和也; 井上健人; 山口公志; 吉村智美; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2014-  155  2014/05
• AtRLCK1によるMAPKKKaを介したキチン認識時のMAPキナーゼの活性化機構の解析

  山口公志; 山田健太; 白川友美; 石川和也; 鳴坂真理; 鳴坂義弘; 市村和也; 深溝慶; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2014-  58  2014/05
• CDPKおよびRLCKがNADPHオキシダーゼを介したROSバーストを制御する

  白石佑太郎; 吉岡美樹; 安達広明; 山口公志; 川崎努; 吉岡博文  日本植物病理学会大会プログラム・講演要旨予稿集  2014-  87  2014/05
• AtRLCK1によるCERK1を介したキチンシグナリングの選択的な制御

  新屋友規; 山口公志; 出崎能丈; 山田健太; 鈴木丸陽; 船間亮汰; 中島正登; 小林佳弘; 竹田潤; 賀来華江; 川崎努; 渋谷直人  日本植物生理学会年会要旨集  55th-  150  2014/03
• 植物免疫におけるOsPUB44の機能解析

  石川和也; 山口公志; 井上健人; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努  日本植物病理学会報  80-  (1)  29  2014/02
• イネのOsRLCK185はNADPHオキシダーゼであるOsRBOHIを介して活性酸素生成を誘導する

  吉岡美樹; 白石佑太郎; 山口公志; 川崎努; 吉岡博文  日本植物病理学会報  80-  (1)  28  -29  2014/02
• MAMPsシグナリングにおける受容体様細胞質キナーゼAtRLCK1の機能解析

  新屋友規; 山口公志; 出崎能丈; 成澤知子; 前田佳菜子; 小林佳弘; 鈴木丸陽; 谷本匠; 竹田潤; 船間亮汰; 山田健太; 鳴坂真理; 鳴坂義弘; 賀来華江; 川崎努; 渋谷直人  日本植物病理学会報  80-  (1)  43  2014/02
• イネとシロイヌナズナで保存されたキチンシグナル伝達経路の解析

  山口公志; 新屋友規; 船間亮汰; 石川和也; 山田健太; 鳴坂真理; 鳴坂義弘; 多田安臣; 市村和也; 渋谷直人; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2013-  53  2013/03
• ユビキチンリガーゼであるOsPUB44の植物免疫における機能解析

  石川和也; 山口公志; 吉村智美; 坂本一明; 村口由一郎; 北野詩織; 小川まどか; 津下誠治; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2013-  53  2013/03
• OsCERK1を介したキチン信号伝達系におけるOsRLCK2の機能の解明

  山田健太; 山口公志; 石川和也; 吉村悠矢; 杉下亮丞; 加星(岸)光子; 高橋章; 内橋幸平; 多田安臣; 市村和也; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2013-  52  2013/03
• キチンシグナリングに関与する受容体様細胞質キナーゼAtRLCK1の機能解析

  新屋友規; 山口公志; 成澤知子; 前田佳菜子; 小林佳弘; 鈴木丸陽; 谷本匠; 十文字純一; 竹田潤; 船間亮汰; 山田健太; 出崎能丈; 鳴坂真理; 鳴坂義弘; 賀来華江; 川崎努; 渋谷直人  日本植物生理学会年会要旨集  54th-  286  2013/03
• 植物免疫におけるOsPUB44の機能およびTypeIIIフェクターによる認識機構の解明

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努  日本植物病理学会報  79-  (1)  50  2013/02
• リン酸化による植物NADPHオキシダーゼの制御機構

  吉岡博文; 安達広明; 白石佑太郎; 中野孝明; 宮川典子; 浅井秀太; 川崎努; 吉岡美樹  日本生体防御学会学術総会講演抄録集  24th-  2013
• 植物の病原菌認識受容体による免疫反応の誘導機構

  川崎努; 山口公志; 山田健太; 石川和也; 吉村智美; 吉村悠矢  日本生体防御学会学術総会講演抄録集  24th-  25  2013
• PAMPs-triggered immunity targeted by pathogen effectors.

  川崎努; 山口公志; 石川和也; 吉村智美; 山田健太; 吉村悠矢  日本植物病理学会報  79-  (4)  263-268 (J-STAGE)  -268  2013
• イネにおけるPAMPs誘導抵抗性の情報伝達機構と病原菌の感染戦略

  川崎努; 山口公志; 石川和也; 吉村智美; 山田健太; 吉村悠矢  日本植物病理学会植物感染生理談話会論文集  (47)  23  -32  2012/08
• キチン認識受容体OsCERK1の相互作用因子OsRLCK2を介したMAPキナーゼ活性化機構の解明

  山口公志; 山田健太; 石川和也; 加星(岸)光子; 高橋章; 林長生; 市村和也; 島本功; 吉岡博文; 川崎努  日本植物細胞分子生物学会大会・シンポジウム講演要旨集  30th-  96  2012/08
• 植物免疫におけるOsPUB44の機能と病原菌エフェクターによる阻害機構

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2012-  92  2012/03
• 病原菌エフェクターの標的であるOsRLCKを介したキチンシグナル伝達機構の解明

  山口公志; 石川和也; 山田健太; 石濱信明; 濱田聡; 津下誠治; 島本功; 吉岡博文; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2012-  92  2012/03
• 病原菌エフェクターの標的であるOsRLCKを介したキチンシグナル伝達機構の解明

  山口公志; 石川和也; 山田健太; 石濱信明; 濱田聡; 津下誠治; 吉岡博文; 島本功; 川崎努  日本植物生理学会年会要旨集  53rd-  176  2012/03
• 植物免疫におけるOsPUB44の機能とType IIIエフェクターXoo3222による阻害機構

  石川和也; 山口公志; 坂本一明; 村口由一郎; 津下誠治; 島本功; 児嶋長次郎; 川崎努  日本植物生理学会年会要旨集  53rd-  177  2012/03
• イネ白葉枯病菌エフェクターXopPの標的因子の同定および機能解析

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 児嶋長次郎; 川崎努  日本植物病理学会報  78-  (1)  45  -46  2012/02
• 白葉枯病菌エフェクターの新奇標的因子OsRLCKの解析

  山口公志; 石川和也; 石濱信明; 古谷綾子; 落合弘和; 津下誠治; 島本功; 吉岡博文; 川崎努  日本植物病理学会報  78-  (1)  46  2012/02
• イネの自然免疫応答に関わる蛋白質,OsRac1の構造学的解析

  小佐見謙一; 大木出; 林こころ; 田畑亮; 薄衣砂弥香; 川崎努; 川崎努; 中川敦史; 藤原敏道; 島本功; 児嶋長次郎; 児嶋長次郎  日本植物生理学会年会要旨集  53rd-  2012
• イネ低分子量G蛋白質OsRac1の結晶構造解析と変異体デザインによるNADPHオキシダーゼOsRbohB制御機構の解明

  小佐見謙一; 大木出; 長野稔; 林こころ; 田畑亮; 薄衣砂弥香; 川崎努; 中川敦史; 藤原敏道; 島本功; 児嶋長次郎; 児嶋長次郎  日本分子生物学会年会プログラム・要旨集(Web)  35th-  2012
• 細胞膜上でのNLRファミリー免疫受容体PitによるRhoファミリーGタンパク質OsRac1の活性化がイネ免疫に重要である

  河野洋治; 赤松明; 林敬子; 宝泉雄介; 奥田淳; 中島綾子; 高橋弘喜; 吉田均; WONG Hann Ling; 川崎努; 島本功  日本分子生物学会年会プログラム・要旨集(Web)  35th-  4W9I-4 (WEB ONLY)  2012
• イネ白葉枯病菌エフェクターが標的とするOsRLCKの解析

  山口公志; 石川和也; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2011-  98  2011/03
• イネ白葉枯病菌エフェクターXopPの標的因子の同定

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物生理学会年会要旨集  52nd-  312  2011/03
• 白葉枯病菌エフェクターの標的因子OsRLCKsの同定と解析

  山口公志; 石川和也; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物生理学会年会要旨集  52nd-  263  2011/03
• イネ白葉枯病菌エフェクターXopPの標的因子の機能解析

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2011-  184  2011/03
• 植物の自然免疫応答に関わる低分子量G蛋白質の構造学的解析

  小佐見謙一; 大木出; 林こころ; 田畑亮; 薄衣砂弥香; 川崎努; 中川敦史; 藤原敏道; 島本功; 児嶋長次郎; 児嶋長次郎  日本蛋白質科学会年会プログラム・要旨集  11th-  2011
• イネの自然免疫応答に関わる低分子G蛋白質OsRac1の構造解析

  小佐見謙一; 大木出; 林こころ; 田畑亮; 薄衣砂弥香; 川崎努; 川崎努; 中川敦史; 藤原敏道; 島本功; 児嶋長次郎; 児嶋長次郎  日本分子生物学会年会プログラム・要旨集(Web)  34th-  2011
• Identification 0f Host Target Factors 0f XopP, A Type III Effector Secreted By Xanthomonas Oryzae Pv. Oryzae

  Ishikawa Kazuya; Yamaguchi Koji; Furutani Ayako; Ochiai Hirokazu; Tsuge Seiji; Shimamoto Ko; Kawasaki Tsutomu  Supplement  2011-  (0)  792  -792  2011
• Functional Analysis Of OsRLCKs Targeted By Xanthomonas oryzae Effector

  Yamaguchi Koji; Ishikawa Kazuya; Furutani Ayako; Ochiai Hirokazu; Tsuge Seiji; Shimamoto Ko; Kawasaki Tsutomu  Supplement  2011-  (0)  606  -606  2011
• イネ白葉枯病菌エフェクターを利用したイネ耐病性機構の解明

  山口公志; 石川和也; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本農芸化学会関西支部講演会講演要旨集  466th-  27  2010/10
• イネ白葉枯病菌エフェクターXopPの標的宿主因子の探索

  石川和也; 山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本農芸化学会関西支部講演会講演要旨集  466th-  28  2010/10
• イネ白葉枯病菌エフェクターを利用したイネPAMPs誘導抵抗性の解析

  山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物病理学会大会プログラム・講演要旨予稿集  2010-  75  2010/03
• Rタンパク質によるGタンパク質OsRac1の活性化が植物免疫に重要である

  河野洋治; 赤松明; 林敬子; 宝泉雄介; 奥田淳; 中島綾子; 高橋弘喜; 吉田均; WONG H.‐L; 川崎努; 島本功  日本植物病理学会大会プログラム・講演要旨予稿集  2010-  82  2010/03
• 白葉枯病菌エフェクターが標的とする植物免疫因子の探索

  山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物生理学会年会要旨集  51st-  146  2010/03
• Rタンパク質によるGタンパク質OsRac1の活性化が植物免疫に重要である

  河野洋治; 赤松明; 林敬子; 宝泉雄介; 中島綾子; 高橋弘喜; 吉田均; WONG Hann Ling; 川崎努; 島本功  日本植物生理学会年会要旨集  51st-  147  2010/03
• 白葉枯病菌タイプIIIエフェクター導入形質転換イネの作出

  古谷綾子; 秋本千春; 山口公志; 川崎努; 島本功; 奥尚; 津下誠治; 落合弘和  日本植物病理学会報  76-  (1)  57  2010/02
• OsRac1-mediated ROS production in rice innate immunity

  Shimamoto Ko; Wong Hann Ling; Kawano Yoji; Ishikawa Yosuke; Oda Takashi; Shimizu Toshiyuki; Kawasaki Tsutomu  Plant and Cell Physiology Supplement  2010-  (0)  S0020  -S0020  2010
• イネ白葉枯病菌Type IIIエフェクターの機能解析

  山口公志; 古谷綾子; 落合弘和; 津下誠治; 島本功; 川崎努  日本植物病理学会報  75-  (3)  212  2009/08
• OsRac1は抵抗性(R)タンパク質を介した植物免疫にも関与する

  河野洋治; 林敬子; 赤松明; 宝泉雄介; LOH Pek Chin; 中島綾子; 高橋弘喜; 吉田均; 川崎努; 島本功  日本植物生理学会年会要旨集  50th-  197  2009/03
• 低分子量GTP結合タンパク質OsRac1とNBS‐LRRタンパク質の相互作用

  河野洋治; 中島綾子; 高橋弘喜; 川崎努; 島本功  日本植物生理学会年会要旨集  49th-  119  2008/03
• Molecular analysis of the defensome protein complex containing RacGTPase which plays a key role in defense signaling of rice

  Phuong Thao Nguyen; Letian Chen; Ayako Nakashima; Shin-ichiro Hara; Priti Krishna; Kenji Umemura; Akira Takahashi; Ken Shirasu; Tsutomu Kawasaki; Ko Shimamoto  PLANT AND CELL PHYSIOLOGY  48-  S48  -S48  2007
• Proteomics of lipid raft similar to Are lipid rafts associated with defense signaling of rice similar to.

  Masayuki Fujiwara; Minori Hiratsuka; Tsutomu Kawasaki; Ko Shimamoto  PLANT AND CELL PHYSIOLOGY  48-  S249  -S249  2007
• (62) Proteome Analysis of Lipid Rafts Associated with Defense Signaling of Rice(Abstract of the Paper Presented at the 2006 Annual Meeting in Sapporo)

  Fujiwara M.; Hiratsuka M.; Kawasaki T.; Shimamoto K.  Annals of the Phytopathological Society of Japan  72-  (4)  218  -218  2006/11
• イネにおけるRacGTPaseとRタンパク質との相互作用の解析

  高橋弘喜; 中島綾子; 川崎努; 島本功  日本植物生理学会年会要旨集  47th-  158  2006/03
• Analysis of interaction between a small GTPase OsRac1 and R-protein

  H Takahashi; A Nakashima; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  47-  S81  -S81  2006
• Proteome analysis of lipid rafts associated with defense signaling of rice

  M Fujiwara; M Hiratsuka; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  47-  S214  -S214  2006
• RWD/OsRACK1 is a novel factor involved in G protein-mediated plant immunity

  A Nakashima; M Kuwano; M Fujiwara; W Hann-Ling; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  47-  S80  -S80  2006
• イネ低分子量GTPase OsRac1が制御する遺伝子群の網羅的発現解析

  森野和子; 川崎努; 島本功; 川田元滋  日本分子生物学会年会講演要旨集  28th-  2005
• Analysis of OsRacl protein complex involved in defense signaling of rice

  PT Nguyen; S Hara; L Chen; A Nakashima; T Kawasaki; K Umemura; A Takahashi; K Shirasu; K Shimamoto  PLANT AND CELL PHYSIOLOGY  46-  S92  -S92  2005
• *Rar1 is important for disease resistance in rice

  LT Chen; S Hara; NP Thao; K Umemura; A Takahashi; K Shirasu; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  46-  S124  -S124  2005
• The rice small GTPase OsRac1, a regulator of the disease resistance signaling, functions during development of lateral roots and tillers

  K Morino; Y Iwasaki; M Iwata; K Umemura; T Kawasaki; K Shimamoto; M Kawata  PLANT AND CELL PHYSIOLOGY  46-  S193  -S193  2005
• Proteome analysis of OsRac1 signaling in defense response of rice

  M Fujiwara; K Umemura; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  46-  S124  -S124  2005
• Identification of the small GTPase OsRacl interacting proteins by affinity chromatography

  A Nakashima; M Kuwano; M Fujiwara; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  46-  S92  -S92  2005
• Analysis of the OsRac1 complex involved in defense signaling of rice.

  Y Kawaguchi; M Fujiwara; PT Nguyen; A Nakashima; K Umemura; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  46-  S124  -S124  2005
• プルダウンアッセイ法

  川崎努  植物細胞工学「モデル植物の実験プロトコール」  243  -246  2005
• (6) Regulation of ROS Production by Small G Protein OsRac in Rice Defense Response(Abstracts of the Papers Presented at the Annual Meeting of the Society, Fukuoka, March 28-30, 2004)

  Kawasaki T.; Pinontoan Reinhard; Wong Hann Ling; Nakashima A.; Umemura K.; Shimamoto K.  Annals of the Phytopathological Society of Japan  70-  (3)  191  -191  2004/08
• イネNADPHオキシダーゼN末端ドメインは二量体を形成する

  林こころ; 田畑亮; 三島正規; 川崎努; 島本功; 児嶋長次郎  日本分子生物学会年会プログラム・講演要旨集  27th-  2004
• Gタンパク質を介した抵抗性のシグナル伝達

  川崎 努; 島本 功  植物細胞工学「分子レベルからみた植物の耐病性」  111  -117  2004
• Proteomic analysis of defense signaling in rice

  M Fujiwara; A Nakashima; H Tsunezuka; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  44-  S18  -S18  2003
• Direct interaction of OsRac with NADPH oxidase regulates ROS production in defense signaling of rice

  R Pinontoan; H Yoshioka; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  44-  S178  -S178  2003
• Downregulation of metallothionein, a reactive oxygen species scavenger, by OsRac1 in defense signaling of rice

  HL Wong; T Sakamoto; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  44-  S178  -S178  2003
• Downregulation of metallothionein expression by small GTPase OsRac1 potentiates oxidative burst and disease resistance

  HL Wong; T Sakamoto; T Kawasaki; K Shimamoto  PLANT AND CELL PHYSIOLOGY  43-  S155  -S155  2002
• RAC SIGNALING IN CELL DEATH AND DISEASE RESISTANCE OF RICE :

  SHIMAMOTO Ko; ONO Eiichiro; HENMI Kenji; WONG Hann Ling; SAKAMOTO Tsuyoshi; KAWASAKI Tsutomu  Plant and cell physiology  41-  s13  2000
• 植物の細胞死

  川崎努  植物細胞工学「植物の細胞分裂」  13-  176  -179  2000
• 植物の病気と細胞死

  川崎 努; 島本 功  植物の化学調節  35-  67  -76  2000
• The small G protein Rac as a molecular switch of programmed cell death in plants

  HENMI Kenji; KAWASAKI Tsutomu; ONO Eiichiro; HATAKEYAMA Satoru; IWANO Megumi; SATOH Hikaru; SHIMAMOTO Ko  Plant and cell physiology  40-  s84  -s84  1999/03
• Enhanced disease resistance in transgenic rice expressing Rac genes

  ONO Eiichiro; HENMI Kenji; KAWASAKI Tsutomu; SHIMAMOTO Ko  Plant and cell physiology  40-  s84  -s84  1999/03
• 植物の病害と耐病性

  島本 功; 川崎 努  植物分子生理学入門  139  -156  1999
• Induction of cell death by small G protein Rac

  HENMI K.; HATAKEYAMA S.; KAWASAKI T.; SHIMAMOTO K.  Plant and cell physiology  39-  S126  -S126  1998/05
• 植物耐病性シグナルの分子機構(バイオミディア 98)

  川崎 努  生物工学会誌 : seibutsu-kogaku kaishi  76-  (7)  316  -316  1998
• CHARACTERIZATION OF RICE CELL DEATH MUTANTS

  TAKAHASHI Akira; KAWASAKI Tsutomu; SATOH Hikaru; SHIMAMOTO Ko  Plant and cell physiology  38-  s57  1997/03
• What is the function of the seed-development specific protein kinase (SPK)?

  ASANO Takayuki; KAWASAKI Tsutomu; TADA Yuichi; SHIMADA Hiroaki  Plant and cell physiology  38-  s137  1997/03
• PCR解析用の簡便なイネゲノムDNA単離法

  川崎努  植物のPCR実験プロトコール  67  -69  1997
• 細胞死と耐病性

  川崎 努; 島本 功  植物細胞工学シリーズ「分子レベルからみた植物の耐病性」  8-  124  -130  1997
• イネ耐病性発現の分子機構の解明に向けて

  大西 徹; 久米 庸介; 鎌田 徹; 畠山 哲; 川崎 努; 井沢 毅; 島本 功  日本分子生物学会年会プログラム・講演要旨集  19-  748  -748  1996/08
• STRUCTURE, ORGANIZATION, AND CHROMOSOMAL LOCATION OF THE GENE ENCODING A FORM OF RICE SOLUBLE STARCH SYNTHASE

  KI TANAKA; S OHNISHI; N KISHIMOTO; T KAWASAKI; T BABA  PLANT PHYSIOLOGY  108-  (2)  677  -683  1995/06
• IDENTIFICATION, CDNA CLONING, AND GENE-EXPRESSION OF SOLUBLE STARCH SYNTHASE IN RICE (ORYZA-SATIVA L) IMMATURE SEEDS

  T BABA; M NISHIHARA; K MIZUNO; T KAWASAKI; H SHIMADA; E KOBAYASHI; S OHNISHI; K TANAKA; Y ARAI  PLANT PHYSIOLOGY  103-  (2)  565  -573  1993/10
• ALTERATION OF THE STRUCTURAL-PROPERTIES OF STARCH COMPONENTS BY THE LACK OF AN ISOFORM OF STARCH BRANCHING ENZYME IN RICE SEEDS

  K MIZUNO; T KAWASAKI; H SHIMADA; H SATOH; E KOBAYASHI; S OKUMURA; Y ARAI; T BABA  JOURNAL OF BIOLOGICAL CHEMISTRY  268-  (25)  19084  -19091  1993/09
• ANTISENSE REGULATION OF THE RICE WAXY GENE-EXPRESSION USING A PCR-AMPLIFIED FRAGMENT OF THE RICE GENOME REDUCES THE AMYLOSE CONTENT IN GRAIN STARCH

  H SHIMADA; Y TADA; T KAWASAKI; T FUJIMURA  THEORETICAL AND APPLIED GENETICS  86-  (6)  665  -672  1993/07

Research Grants & Projects

• Development of next-generation disease-resistant rice

  農林水産省：戦略的国際共同研究推進委託事業・日中二国間共同研究事業

  Date (from‐to) : 2020/09 -2025/03 

  Author : 川崎 努
• 植物に耐病性を付与する病原菌エフェクタートラップ法の開発

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Challenging Research (Exploratory)

  Date (from‐to) : 2020/07 -2023/03 

  Author : 川崎 努

   

  病原菌が、植物で感染拡大をする際、宿主細胞内にエフェクターと呼ばれるタンパク質を分泌する。エフェクターは、植物の免疫誘導を抑制したり、宿主の遺伝子発現を制御して菌の増殖環境を整える機能をもつ。このようにエフェクターは病原菌の病原力の根源となっており、いかにエフェクターの機能を抑制するかが病原菌の増殖抑制において重要な課題となっている。本研究では、エフェクターと相互作用するタンパク質ドメインを、エフェクタートラップドメイン（ETD）として利用し、ETDがエフェクターの機能を阻害するかについて解析を行う。得られた成果をもとに、ETDを利用して、病原菌の感染力を弱体化される次世代型の耐病性技術の開発を行うことを目的としている。 植物の重要病害を引き起こすXanthomonas属やRalstonia属の病原菌は、TALエフェクターをもつ。TALエフェクターは、宿主の核で転写因子として働き、菌の増殖に都合がいい宿主遺伝子を発現させる、最も重要な病原性因子である。TALエフェクターが、NB-LRR型病原菌認識受容体Xa1がもつBEDドメインと相互作用することを見出したため、BEDを発現させた形質転換イネとシロイヌナズナを作製した。本年度、BED発現イネに白葉枯病菌を感染させたが、顕著な病原菌の増殖抑制は見られなかった。一方、シロイヌナズナでは、病原菌の抑制効果が観察され、その有効性が示唆された。
• 植物NB-LRR受容体による免疫活性化と病原菌による宿主転写制御の分子基盤

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

  Date (from‐to) : 2019/04 -2023/03 

  Author : 川崎 努

   

  植物に重要病害を引き起こすXanthomonas属やRalstonia属の病原菌は、植物の核において転写因子として働くTALエフェクターを植物細胞内に送り込む。TALエフェクターは、菌の増殖に有利に働く遺伝子を制御し、感染を拡大させることが知られている。一方、イネ品種黄玉がもつNB-LRR型受容体であるXa1は、TALエフェクターを認識して防御反応を誘導することが知られている。しかし、植物のNB-LRR受容体については、それらによる免疫活性化機構についてもあまり理解されていない。そこで、本研究では、Xa1による免疫誘導機構を解析することで、NB-LRR型受容体による免疫活性化機構を明らかにすることを目的としている。 本年度は、Xa1と相互作用する因子として見出したRAP転写制御因子に関して解析を進め、RAPがTALエフェクターと直接的に相互作用することを見出した。また、細胞内においてXa1とTALエフェクターの複合体形成が見られるものの、直接な相互作用は検出できていない。そのため、Xa1は、RAPを介してTALエフェクターを認識し、免疫を活性化することが示唆された。また、前年度の解析により、RAPの過剰発現体とノックアウト変異体が共に強い抵抗性を誘導することが明らかになった。本年度、詳細な遺伝子発現解析を行い、RAPの過剰発現体とノックアウト変異体では、異なるタイプの遺伝子が活性化されていることがわかった。これらの結果は、前年度に提唱した「RAPによって抑制されるイネの遺伝子が存在し、その遺伝子は、Xa1依存型抵抗性を正に制御している」というモデルと一致した。
• 植物に持続的な耐病性を付与する農薬による免疫プライミング活性化機構の解明

  三菱財団：自然科学研究助成

  Date (from‐to) : 2018/10 -2020/09 

  Author : 川崎 努
• イネのパターン誘導免疫と免疫プライミングの分子機構の解明

  文部科学省：新学術領域研究

  Date (from‐to) : 2018/04 -2020/03 

  Author : 川崎 努
• 分子標的剤を利用した病原細菌の三型分泌装置形成の制御機構の解明と新規農薬の開発

  日本学術振興会：挑戦的萌芽研究

  Date (from‐to) : 2016/04 -2019/03 

  Author : 川崎 努
• 植物免疫における受容体型細胞質キナーゼを介したMAPKカスケードの活性化機構

  日本学術振興会：基盤研究A

  Date (from‐to) : 2015/04 -2019/03 

  Author : 川崎 努
• MAPKカスケードを介した植物免疫記憶の制御機構

  日本学術振興会：新学術領域研究

  Date (from‐to) : 2016/04 -2018/03 

  Author : 川崎 努
• 植物免疫における受容体シグナルのクロストークの分子基盤の解明

  文部科学省：新学術領域研究

  Date (from‐to) : 2015/04 -2017/03 

  Author : 川崎 努
• 植物の病原菌認識に伴うMAPKカスケードの活性化機構の解明

  文部科学省：科学研究費補助金(新学術領域研究(研究領域提案型))

  Date (from‐to) : 2013 -2014 

  Author : 川崎 努

   

  植物は、細胞膜上に存在する病原菌認識受容体を介して、病原菌の構成成分を認識し、迅速な免疫反応を誘導する。その免疫反応の誘導において、MAPキナーゼカスケードが極めて重要な働きをしていることが知られているが、植物では受容体からMAPキナーゼにどのように情報が伝達されているかが明らかになっていない。これまでに、病原菌の構成成分であるキチンを認識する受容体CERK1によりリン酸化される因子として細胞質リン酸化キナーゼであるPBL27を同定し、さらにPBL27がMAPカスケードの起点となるMAPKKKaと相互作用することが明らかとなった。さらに、pbl27変異体およびmapkkka変異体を用いた遺伝学的解析により、CERK1-PBL27-MAPKKKa-MKK4/MKK5-MPK3/MPK6のシグナル伝達系が示唆された。そこで、CERK1、PBL27、MAPKKKaの組換えタンパク質を調製し、PBL27によるMAPKKKaのリン酸化を解析したところ、PBL27がMAPKKKaのC末端側をリン酸化すること、さらにそのリン酸化反応には、PBL27がCERK1によるリン酸化により活性化されていることが必要であることがわかった。さらに、PBL27によってリン酸化されるMAPKKKaの６個のアミノ酸残基を特定し、それらのアミノ酸をアラニンに置換した変異タンパク質はmapkkka変異体を相補できないことがわかった。この結果は、MAPKKKaの活性化にはPBL27によるリン酸化が必須であることを示唆している。さらに、MAPKKKaがMKK4とMKK5の活性化モチーフをリン酸化することが明らかとなり、CERK1-PBL27-MAPKKKa-MKK4/MKK5-MPK3/MPK6のシグナル伝達系を生化学的にも証明することに成功した。
• Serotonin-mediated immune signaling in plants

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2012 -2013 

  Author : KAWASAKI Tsutomu

   

  Although serotonin is known as a neurotransmitter in animal, its function in plants remains to be identified. We identified rice SL gene encoding serotonin synthesizing enzyme involved in defense responses. In this work, we found that serotonin induces expression of defense genes, callose deposition, and activation of MAP kinase in Arabidopsis. Therefore, it is likely that serotonin functions as immune factor in plants.
• 植物と病原菌の攻防によって生じた遺伝子相関の分子基盤

  文部科学省：科学研究費補助金(新学術領域研究(研究領域提案型))

  Date (from‐to) : 2012 -2013 

  Author : 川崎 努

   

  Xoo3222がターゲットとする宿主免疫因子の探索により、OsPUB44が同定された。Xoo3222は、OsPUB44のU-boxドメインに結合することにより、OsPUB44のユビキチンリガーゼ活性を阻害した。また、イネ細胞を26Sプロテオソームの阻害剤で処理すると、OsPUB44が蓄積することから、OsPUB44のタンパク質量がユビキチン化により制御されていると考えられる。実際、Xoo3222を発現するイネ培養細胞では、OsPUB44のタンパク質量が増加しており、これはXoo3222がOsPUB44の自己ユビキチン化を阻害していることを示唆している。植物免疫におけるOsPUB44の機能を明らかにするため、RNAi法によりOsPUB44の発現を抑制した培養細胞と植物体を作成した。RNAi培養細胞では、病原菌の構成成分であるキチンやペプチドグリカンに応答した防御応答が抑制された。また、RNAi植物では、イネ白葉枯病菌に対する抵抗性が抑制されていた。このように、OsPUB44はイネの免疫誘導において、ポジティブレギュレーターとして機能していることが示された。さらに、OsPUB44による免疫誘導の分子機構を明らかにするため、OsPUB44のARMドメインに結合する因子を探索し、機能未知なOsPUB44 interactor1 (PBI1)を同定した。BiFC法を用いた解析により、OsPUB44とPBI1は細胞内で相互作用することが明らかになった。そこで、PBI1の機能を明らかにするため、RNAi法を用いてPBI1の発現抑制体を作成した。
• Molecular function of plant immune factors targeted by pathogen effectors

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2011 -2013 

  Author : KAWASAKI Tsutomu

   

  Plants recognize infection of pathogens through recognition of pathogen-associated molecular patterns with the receptors, which triggers a series of immune responses. To suppress host immunity, the pathogens deliver the effectors into plant cells. In this work, we identified OsRLCK185 which transmits the immune signals from the receptor to the downstream components. In addition, Xoo1488, an effector of Xanthomonas oryzae, inhibits the function of OsRLCK185 to suppress host immunity.
• 植物免疫シグナル分子を利用した高精度耐病性植物の創生

  新技術・新分野創出のための基礎研究推進事業

  Date (from‐to) : 2007 -2011 

  Author : 川崎努

   

  植物免疫因子の機能解明により、環境にやさしい新規な耐病性植物を開発する
• Molecular basis of Rac GTPase in plant innate immunity

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

  Date (from‐to) : 2007 -2011 

  Author : SHIMAMOTO Ko; KAWASAKI Tsutomu; WONG Hann ling; TERADA Rie; KAWANO Yoji

   

  We have previously reported that small GTPase OsRac1 plays important roles in rice innate immunity. However, it is largely unknown how OsRac1 induces immune responses. In this study, we showed that OsRac1 forms a complex termed Defensome with various downstream proteins, including R proteins, pattern recognition receptors, a scaffolding protein, and cochaperone proteins. OsRac1 also plays a dual role in the induction of ROS production through direct interactions with NADPH oxidases and the suppression of the ROS scavenger. Moreover, we demonstrate here that Defensome acts as an important regulator in rice innate immunity.
• Molecular basis of G-protein mediated PAMPs signaling

  Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))

  Date (from‐to) : 2007 -2009 

  Author : Tsutomu KAWASAKI

   

  Plants induce a series of immune responses through recognition of pathogen-derived molecules (Pathogen-associated molecular patterns ; PAMPs). We analyzed the molecular mechanism of activation of Rac/Rop GTPase during PAMPs triggered responses, and found that Rac/Rop GTPase is regulated through activation of Rac/Rop GEF by PAMPs receptor
• 植物の自然免疫におけるGタンパク質Racの活性化機構

  文部科学省：科学研究費補助金(特定領域研究)

  Date (from‐to) : 2006 -2007 

  Author : 川崎 努

   

  申請者はRacファミリーのイネ低分子量Gタンパク質OsRac1が病原体の侵入認識から抵抗性発現に至る過程で信号伝達の鍵因子として機能していることを明らかにしてきた。しかし、耐病性反応時にOsRac1を活性化するGDP-GTP交換因子(GEF)については明らかになっていない。本研究課題では、耐病性反応におけるRacGEFを同定し、Racの活性化機構を解析することを目的としている。近年、植物の特有の機能ドメインであるPRONEドメインがGEF活性を有することが明らかにされた。イネには11個のPRONEドメインをもつ遺伝子(OsRacGEF1-11)が存在する。本研究プロジェクトでは、これらのRacGEFについて、分子生物学的および生化学的な解析を行ない、OsRac1のGEFの同定を試みた。11個の全てのRacGEFについて、組換えタンパク質を調製し、OsRac1に対するGEF活性を調べた。その結果、全てのOsRacGEFがOsRac1に対してGEF活性を示したが、特にOsRacGEF7とOsRacGEF8が強いGEF活性を示すことが明らかとなった。また、OsRacGEFの細胞内の局在部位を調べるため、蛍光タンパク質と融合させたOsRacGEFをイネ細胞内で発現させ、局在解析を行った。その結果、RacGEF4は核に、RacGEF7、RacGEF8、RacGEF9は細胞膜と細胞質に、RacGEF10は細胞質に、RacGEF11は微小管に存在することが明らかとなった。OsRac1は細胞膜に多く存在することがわかっており、RacGEF7、RacGEF8、RacGEF9がOsRac1と共局在しているど考えられた。また、RacGEF7とRacGEF8の過剰発現体では、恒常的に防御遺伝子の発現が誘導されており、この2つの遺伝子が耐病性反応に関わるOsRac1のGEFとして働いている可能性が示された。
• Studies on signal transduction pathways in disease resistance

  Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(特定領域研究(A), 特定領域研究)

  Date (from‐to) : 2000 -2005 

  Author : 川崎 努; Kazuyuki HIRATSUKA; 平塚 和之; 進士 秀明; 川崎 努; Hideaki SHINSHI; Thutomu KAWASAKI

   

  In order to investigate signaling pathways involved in disease resistance, research on regulated mechanisms of hypersensitive cell death of rice has been conducted and obtained important results on G-protein mediated signaling network in plants. Development. of novel bioluminescenoe reporter system for monitoring gene expression in response to pathogen attack has also been carried out and the system enables us to monitor defense gene expression in vivo that can be applicable to search for agents and genes that control disease resistance in higher plants. A study of DNA・damage responsive genes and pathogenesis-related genes resulted in the identification of novel cisregulatory elements and demonstrated a relationship between DN-damage and inducible resistance in plant cells. A series of studies on regulated expression of defense gene promoters indicated an involvement of copper ion in disease resistance induced by copper based pesticide. Further investigations of transcriptional regulation of defense related genes with emphasis on transcription factors have been conducted and successfully obtained a series of results on NPR1-mediated regulation of gene expression. Also, a novel GRAS protein that regulates tissue specific expression of defense-related gene was discovered and analyzed during the course of this project. Studies on regulated expression of elicitor responsive genes have been conducted and the results obtained from a series of extensive investigation using tobacco promoters and transcription factors including WRKY and ERF uncovered the mechanisms that control defense gene expression in plant cells. Results of trans-activation experiments clearly demonstrated the involvement. of W-box mediated regulation of ERF3 gene promoter and the functions of NtWRKY1, 2, 4 that bind to the W-box sequence. All these results mentioned above are important contribution in a viewpoint. of understanding the disease resistance signaling pathways in higher plant and the improvement of plant. disease management.
• 植物の病害抵抗性遺伝子複合体の同定による病原体の認識機構の解明

  文部科学省：科学研究費補助金(若手研究(A))

  Date (from‐to) : 2003 -2004 

  Author : 川崎 努

   

  植物は、抵抗性遺伝子産物を介して病原体の侵入を認識し様々な防御反応を誘導する。近年、抵抗性遺伝子産物は大きな複合体を形成し、病原体の多様なシグナルを認識している可能性が示唆されている。しかし、抵抗性遺伝子産物がどのような因子と複合体を形成し、どのようにシグナルを伝達しているかについては、ほとんど明らかになっていない。本研究では、イネといもち病菌の系を用いて病原体認識の総合的なメカニズムの解明を試みる。いもち病抵抗性遺伝子Pi-aの候補として考えられたRPR1遺伝子は、核酸結合部位(NBS)とロイシンリッチリピート(LRR)をもつ典型的な抵抗性遺伝子をコードしている。RPR1の過剰発現体は、Pi-aに依存した過敏感反応を誘導しないものの、親和性いもち病菌に対して抵抗性を誘導し、防御遺伝子の発現が上昇していた。これは、RPR1がPi-aを相補することが出来なかったものの、過剰発現により抵抗性シグナルを伝達できることが明らかになった。一方、抵抗性誘導のキーレギュレーターとして機能している低分子量Gタンパク質OsRac1と相互作用する因子の探索により、5種のNBS-LRRタンパクが同定された。そこで、OsRac1とRPR1の相互作用を調べたところ、OsRac1はRPR1のNBSドメインと強く結合することが明らかになった。このことは、OsRac1がRPR1と複合体を形成し、認識シグナルを下流に伝達していることが示唆された。他のNBS-LRRとOsRac1の相互作用を調べたところ、多くのNBSドメインがOsRac1と相互作用することが明らかになった。また、OsRac1は他の抵抗性遺伝子産物の調節因子と相互作用することが明らかになっており、NBS-LRR構造をもつ抵抗性遺伝子産物はOsRac1と複合体を形成し、病原体認識および抵抗性誘導を行っていることが示唆された。
• イネいもち病抵抗性遺伝子の単離とそれを利用した耐病性植物の育種

  文部科学省：科学研究費補助金(奨励研究(A))

  Date (from‐to) : 1999 -2000 

  Author : 川崎 努

   

  イネいもち病菌に対する抵抗性関連遺伝子を単離するため、植物の抵抗性遺伝子の間で高度に保存されている核酸結合部位の配列を用いたPCRクローニングにより抵抗性遺伝子の核酸結合部位に似た領域をもつイネ遺伝子を単離した。イネいもち病抵抗性準同質遺伝子系統を用いた解析により、単離した遺伝子は、既知のいもち病抵抗性遺伝子Pi-taとの関連が示唆された。そこで、この遺伝子の全塩基配列を決定したところ、この遺伝子は核酸結合部位とロイシンリッチリピートをもつ抵抗性遺伝子の1つのクラスに属することがわかった。この遺伝子を強制発現させた形質転換イネを作成し、いもち病菌の接種試験をおこなったが、顕著な抵抗性の向上は見られなかった。また、詳細なマッピングの結果、この遺伝子はPi-taとは異なることがわかった。しかし、この研究の過程で、抵抗性反応時に一過的に発現が誘導される遺伝子を単離した。この遺伝子はテルペン合成酵素の相同性をしめし、新規な抵抗性関連遺伝子であることがわかった。現在、この遺伝子を利用した抵抗性育種を検討している。
• Understanding of plant immunity response

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https://researchmap.jp/tsutomu_kawasaki