2018 Fiscal Year Final Research Report
Dynamic focal adhesion molecular islands as revealed by super-spatiotemporal-resolution single fluorescent-molecule localization microscopy
| Project/Area Number |
16H04775
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Research Collaborator |
Kusumi Akihiro
Tsunoyama Takaaki
Shirai Yuki
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 接着斑 / アクチン骨格 / 拡散運動 / 1分子計測 / 超解像 |
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| Outline of Final Research Achievements |
Focal adhesion, or FA, is a micron-sized structure in the plasma membrane (PM), responsible for the movement of the cells involved in stem cell differentiation or in cancer cell invasion. Using an ultrafast camera system we developed, integrin molecules were found to undergo hop diffusion between actin-induced 110-nm-compartments in the bulk PM, once every ~25 ms. They also underwent hop diffusion in the FA region, where the compartment size was about half in area and the residency time within a compartment was ~1.5x longer. Simultaneous use of PALM revealed that integrin immobilization events predominantly occurred where the FA marker protein paxillin densities were high, namely, on the FA-protein islands. These results support the dynamic FA archipelago model, in which FA islands maintained by the actin meshwork are sparsely distributed, allowing the ready entrance-exiting of integrin through the channels between FA islands, which would facilitate rapid FA formation-disintegration.
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| Free Research Field |
生物物理学
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| Academic Significance and Societal Importance of the Research Achievements |
(1) 我々が開発してきた超高速１蛍光分子追跡／PALM超解像技術は、コマーシャルの高感度カメラを利用した技術と比較して10倍以上高速であり、刻々と状態が変化する生細胞観察において、今後、さらに重要性が高まると期待される。
(2) 本研究で注目した接着斑の他にも、ポドソーム、タイトジャンクション、アドヒーレンスジャンクション、シナプスなど、様々な細胞機能の制御を担う接着構造が存在する。本研究で得た「動的群島機構」の概念は、細胞接着の制御という基本的で極めて重要な課題に、「サブミリ秒-数分の時間スケール／１分子-ミクロンサイズの空間スケールにわたる」、「動的な」知見をもたらすものである。
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