Molecular mechanism for orienting membrane and actin dynamics to nascent cell-cell contacts in epithelial cells
Molecular mechanism for orienting membrane and actin dynamics to nascent cell-cell contacts in epithelial cells
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DOI：
10.1074/jbc.m207747200
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发表时间：
2002-11-22
影响因子：
4.8
通讯作者：
Nelson, WJ
中科院分区：
文献类型：
--
作者：
Hansen, MDH;Ehrlich, JS;Nelson, WJ
小GTP酶rac1参与了上皮细胞的细胞迁移和细胞间黏附的调节。然而，对于平衡这些相互竞争的过程所需的rac1活动的空间和时间协调知之甚少。我们从犬肾细胞膜中分离出内源性Rac1蛋白复合体，鉴定出三个主要复合体，包括一个Rac1(p21-激活蛋白激酶)复合体，11个S和16个S Rac1复合体。值得注意的是，在细胞-细胞黏附的启动过程中，Rac1从11个S颗粒转变为16个S颗粒。这种转变可能反映了一种扩散捕获机制，通过这种机制，这些rac1复合体通过与Annexin II的相互作用，定位于钙粘附素介导的细胞-细胞接触。
The small GTPase Rac1 has been implicated in regulation of cell migration and cell-cell adhesion in epithelial cells. Little is known, however, about the spatial and temporal coordination of Rac1 activity required to balance these competing processes. We fractionated endogenous Rac1-containing protein complexes from membranes of Madin-Darby canine kidney cells and identified three major complexes comprising a Rac1(.)PAK (p21-activated kinase) complex, and 11 S and 16 S Rac1 complexes. Significantly, Rac1 shifts from the 11 S to a 16 S particle during initiation of cell-cell adhesion. This shift may reflect a diffusion trapping mechanism by which these Rac1 complexes are localized to cadherin-mediated cell-cell contacts through an interaction with annexin II.