The semaphorin 4D receptor plexin-B1 is a GTPase activating protein for R-Ras
The semaphorin 4D receptor plexin-B1 is a GTPase activating protein for R-Ras
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DOI：
10.1126/science.1097545
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发表时间：
2004-08-06
期刊：
影响因子：
56.9
通讯作者：
Negishi, M
中科院分区：
文献类型：
--
作者：
Oinuma, I;Ishikawa, Y;Negishi, M
丛状蛋白是脑信号蛋白分子的细胞表面受体，它们之间的相互作用控制着多种组织中的细胞粘附和迁移。我们报告说，脑信号蛋白4D（Sema 4D）受体丛蛋白-B1直接刺激内在的鸟苷三磷酸酶（GTdR）活性的R-Ras，一个成员的Ras超家族的小GTP结合蛋白，已被牵连在促进细胞粘附和神经突生长。这种活性需要丛蛋白B1与Rho家族的小GTP结合蛋白Rnd 1相互作用。Plexin-B1-Rnd 1复合物下调R-Ras活性对Sema 4D诱导的海马神经元生长锥塌陷至关重要。因此，丛蛋白-B1介导Sema 4D诱导的排斥性轴突导向信号作为一个GT3激活蛋白R-Ras。
Plexins are cell surface receptors for semaphorin molecules, and their interaction governs cell adhesion and migration in a variety of tissues. We report that the Semaphorin 4D (Sema4D) receptor Plexin-B1 directly stimulates the intrinsic guanosine triphosphatase ( GTPase) activity of R-Ras, a member of the Ras superfamily of small GTP-binding proteins that has been implicated in promoting cell adhesion and neurite outgrowth. This activity required the interaction of Plexin-B1 with Rnd1, a small GTP-binding protein of the Rho family. Down-regulation of R-Ras activity by the Plexin-B1-Rnd1 complex was essential for the Sema4D-induced growth cone collapse in hippocampal neurons. Thus, Plexin-B1 mediates Sema4D-induced repulsive axon guidance signaling by acting as a GTPase activating protein for R-Ras.