| Project/Area Number |
23390039
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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 |
General anatomy (including histology/embryology)
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| Research Institution | Kagawa University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
KAWAI Katsuhisa 香川大学, 医学部, 助教 (80534510)
EGAMI Youhei 香川大学, 医学部, 助教 (80432780)
MIYAKE Katsuya 香川大学, 医学部, 准教授 (30219745)
FUJII Makoto 香川大学, 医学部, 助教 (30398086)
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| Project Period (FY) |
2011-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥16,770,000 (Direct Cost: ¥12,900,000、Indirect Cost: ¥3,870,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2013: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2012: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2011: ¥10,400,000 (Direct Cost: ¥8,000,000、Indirect Cost: ¥2,400,000)
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| Keywords | Rac1 / 分子スイッチ / マクロパイノサイトーシス / 蛍光イメージング / 光遺伝学 / マクロファージ / 細胞 / 顕微鏡 / GTPase / 光制御 / 細胞骨格 / 顕微鏡技術 / アクチン細胞骨格 / 小胞形成 |
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| Outline of Final Research Achievements |
We attempted to characterize the activation and deactivation of Rac1 in macropinocytosis using microscopic photo-manipulation. Expression of genetically encoded photoactivatable(PA)-Rac1 in RAW264 macrophages enabled the local, reversible control of macropinocytosis using blue laser irradiation. Marked membrane ruffling and unclosed pre-macropinosomes were observed in the irradiated region of macrophages under the persistent activation of PA-Rac1. Although PI4,5P2 and actin accumulation were observed to this region, the recruitment of maturating endosome markers, such as PI3P and Rab21, was restricted until PA-Rac1 deactivation. After deactivating PA-Rac1 by ceasing irradiation, membrane ruffling immediately receded, and the macropinosomes acquired maturation markers. These data suggest that activation of Rac1 is sufficient to induce membrane ruffling and macropinocytic cup formation, but subsequent deactivation of Rac1 is required for macropinosome closure and further maturation.
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