trans-interactions of nectins induce formation of filopodia and lamellipodia through the respective activation of Cdc42 and Rac small G proteins
trans-interactions of nectins induce formation of filopodia and lamellipodia through the respective activation of Cdc42 and Rac small G proteins
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DOI：
10.1074/jbc.m209846200
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发表时间：
2002-12-27
影响因子：
4.8
通讯作者：
Takai, Y
中科院分区：
文献类型：
--
作者：
Kawakatsu, T;Shimizu, K;Takai, Y
Nectins和afadin构成了一种新的细胞-细胞粘附系统，与钙粘蛋白在粘附连接（AJs）的组织中发挥协同作用。连接素是钙离子非依赖性的免疫球蛋白样细胞-细胞粘附分子，而afadin是连接素和肌动蛋白结合蛋白，其将连接素连接到肌动蛋白细胞骨架。Rac和Cdc 42小G蛋白与AJs的组织有关，但它们的作用方式仍不清楚。最近已显示E-钙粘蛋白的反式相互作用诱导Rac的激活，但不诱导Cdc 42的激活。我们在这里表明，反式相互作用的nectins诱导形成的丝状伪足和片状伪足通过各自激活的Cdc 42和Rac。Cdc 42的激活是必要的，但不是足够的，为Rac诱导的片状伪足的形成，而Rac的激活是不必要的Cdc 42诱导的丝状伪足的形成。nectin的这些作用需要它们的细胞质尾区，而不是它们与afadin的结合。我们建议在这里的连接蛋白和小G蛋白的组织AJs之间的功能关系。
Nectins and afadin constitute a novel cell-cell adhesion system that plays a cooperative role with cadherins in the organization of adherens junctions (AJs). Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules, and afadin is a nectin- and actin filament-binding protein that connects nectins to the actin cytoskeleton. Rac and Cdc42 small G proteins have been implicated in the organization of AJs, but their modes of action remain unknown. The trans-interaction of E-cadherin has recently been shown to induce the activation of Rac, but not that of Cdc42. We show here that the trans-interactions of nectins induce the formation of filopodia and lamellipodia through the respective activation of Cdc42 and Rac. The Cdc42 activation is necessary, but not sufficient, for the Rac-induced formation of lamellipodia, whereas the Rac activation is not necessary for the Cdc42-induced formation of filopodia. These effects of nectins require their cytoplasmic tail but not their association with afadin. We propose here the functional relationship between nectins and the small G proteins in the organization of AJs.