Investigation of chemotactic range extension mechanism

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K15105
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biophysics
• Research Institution: Osaka University
• Principal Investigator: MIYANAGA Yukihiro 大阪大学, 生命機能研究科, 助教 (70569772)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 走化性 / 濃度レンジ / GPCR / Gタンパク質 / 1分子イメージング / 細胞内シグナル伝達 / 細胞性粘菌

Outline of Final Research Achievements

The wide range sensing of extracellular signals is a common feature of various sensory cells. Eukaryotic chemotactic cells driven by GPCRs and their cognate G proteins are one example. This system endows the cells directional motility towards their destination over long distances. We reveal that the receptor-mediated capturing of G proteins mediate chemotactic signaling at the higher concentration ranges. Single-molecule imaging analysis showed that the activated Gα subunit forms an unconventional complex with the agonist-bound receptor. This complex formation of GPCR-Gα increased the membrane-binding time of individual Gα molecules and therefore resulted in the local accumulation of Gα. Our findings provide an additional chemotactic dynamic range mechanism in which multiple G protein dynamics positively contribute to the production of gradient information.

Free Research Field

生物物理

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は，広い濃度範囲で安定して実現される真核細胞の走化性のメカニズム解明において重要なものである。GPCRは視覚や神経伝達物質，ホルモンなどの受容など，様々な生理現象に関わっており，本研究で見出したGPCRとGタンパク質の新たな複合体形成様式は，走化性のみならず，GPCRを介したシグナル伝達全般においても同様に働く可能性がある。