2019 Fiscal Year Final Research Report
Functional mechanism of the GTP/ATP-binding proteins that regulate bacterial flagellar number.
Project/Area Number |
16H04774
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Biophysics
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Research Institution | Nagoya University |
Principal Investigator |
Kojima Seiji 名古屋大学, 理学研究科, 准教授 (70420362)
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Project Period (FY) |
2016-04-01 – 2020-03-31
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Keywords | 細菌べん毛 / タンパク質局在 / ATPase / GTPase / FlhF / FlhG / HubP / SflA |
Outline of Final Research Achievements |
Vibrio alginolyticus has a single polar flagellum used for swimming motility. We found that FlhG, the negative regulator for flagellar number and ATPase, exists as a monomer in the presence of ATP and do not form dimer as seen for its paralog MinD. We suggest that an ATP-bound FlhG localizes at cell pole via the membrane protein HubP, and then directly inhibits FlhF, the positive regulator for flagellar number. On the other hand, FlhF intrinsically localizes at cell pole. We found that a GTP-bound FlhF forms dimer and its GTPase activity was stimulated by the N-terminal region of FlhG. Our current model proposes that the nucleotide-bound active states of FlhF and FlhG function at cell pole, and their regulatory activities to determine flagellar number is strictly balanced at pole, so as to generate only a single polar flagellum.
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Free Research Field |
生化学・分子生物学・生物物理学
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Academic Significance and Societal Importance of the Research Achievements |
機能部位への生体分子の適量配置は、生命機能の正常な発現と維持に必須で、あらゆる生物に見られる普遍的生命現象である。細菌べん毛は適量適所配置により運動能を実現することや、細菌の特色である増殖が早く様々な研究手法が適用可能であることから、優れた研究対象である。我々はべん毛形成を制御する正と負の因子の生化学活性と細胞内での振る舞い(極局在)を検討し、遺伝子発現レベルでの制御だけでなく、翻訳後の制御機構が因子の生化学活性と共役して細胞の極で起こることを見出した。加えて細胞の極が細胞内において特殊な状況を生み出し、超分子複合体の構築に適切な環境を与えていることを見出した点にも意義がある。
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