Functions and modes of action of small G proteins in cell adhesion and migration

小G蛋白在细胞粘附和迁移中的功能和作用方式

• 批准号: 11680632
• 负责人: SASAKI Takuya
• 金额: $ 2.5万
• 依托单位: The University of Tokushima School of Medicine (2000)Osaka University (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680632/
• 关键词: cell migration; vesicle transport; Rab family; Rab11; Rabphilin-11; microtubule; mSec13; recycling; 細胞骨格; Rhoファミリー低分子量G蛋白質; cell migration; vesicle transport; Rab family; Rab11; Rabphilin-11; microtubule; mSec13; recycling; 細胞骨格; Rhoファミリー低分子量G蛋白質

When epithelial cells start to migrate, cell-cell junctions are first disrupted. During migration, membrane protrusions, such as lamellipodia and filopodia, at the cell front, and retraction at the cell rear are externally observed, and dynamic reorganization of the actin cytoskeleton is internally observed. We have recently clarified that the Rho and Rab family small G proteins coordinately regulate cell adhesion and migration of cultured MDCK cells. The Rab family consists of over thirty members. We have found that some Rab family members are involved in HGF- or phorbol esterinduced endocytosis and recycling of cadherin and integrin. Rab11, a member of Rab family, has been implicated in vesicle recycling. During this support from 1999 to 2000, we have focused on studying the function and mode of action of Rab11 in cell migration. The results obtained are as follows :(1) We have isolated a downstream target of Rab11, named Rabphilin-11, from bovine brain. We have found that rabphilin-11 is localized at perinuclear regions, presumably the Golgi complex and recycling endosomes in MDCK cells.(2) We have found that Rabphilin-11 is localized not only at perinuclear regions but also along microtubules, which are oriented toward membrane lammelipodia in HeLa cells cultured on fibronectin. Overexpression of rabphilin-11 mutant reduces accumulation of transferrin at perinuclear regoins and cell migratoin.(3) We have found that rabphilin-11 directly binds the mammalian counterpart of yeast Sec13 proteins (mSec13) in cell-free and intact cell systems. Disruption of the rabphilin-11-mSec13 interaction by overexpression of the mSec13-binding region of rabphilin-11 impairs vesicle trafficking.

当上皮细胞开始迁移时，首先会破坏细胞 - 细胞连接。在迁移过程中，在外部观察到膜突起，例如细胞正面的膜状突起，并在细胞后部回缩，并且在内部观察到肌动蛋白细胞骨架的动态重组。我们最近澄清说，Rho和Rab家族小G蛋白协同调节了培养的MDCK细胞的细胞粘附和迁移。 Rab家族由三十多名成员组成。我们发现，一些RAB家庭成员参与HGF或佛波酯诱导的内吞作用以及钙粘蛋白和整联蛋白的回收利用。 Rab11是Rab家族的成员，与囊泡回收有关。在1999年至2000年的支持期间，我们专注于研究RAB11在细胞迁移中的功能和作用方式。所获得的结果如下：（1）我们已经从牛脑分离了一个名为Rabphilin-11的Rab11的下游靶标。我们已经发现，Rabphilin-11位于核周区域，大概是MDCK细胞中的高尔基体复合物和回收的内体。（2）我们发现，Rabphilin-11不仅在围perin核区域定位于围核区域，而且沿着微管沿着微纤维培养了膜型纤维型纤维型纤维化型纤维化型纤维化菌株。 Rabphilin-11突变体的过表达减少了核核酸酯和细胞偏他素处转铁蛋白的积累。（3）我们发现Rabphilin-111直接结合了酵母菌SEC13蛋白（MSEC13）在无细胞和完整细胞系统中的哺乳动物对应物。 Rabphilin-11-MSEC13的破坏通过过表达Rabphilin-11的MSEC13结合区域会损害囊泡运输。