Membrane transport of WAVE2 and lamellipodia formation require Pak1 that mediates phosphorylation and recruitment of stathmin/Op18 to Pak1-WAVE2-kinesin complex
Membrane transport of WAVE2 and lamellipodia formation require Pak1 that mediates phosphorylation and recruitment of stathmin/Op18 to Pak1-WAVE2-kinesin complex
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DOI：
10.1016/j.cellsig.2009.01.007
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发表时间：
2009-05-01
影响因子：
4.8
通讯作者：
Suzuki, Katsuo
中科院分区：
文献类型：
--
作者：
Takahashi, Kazuhide;Suzuki, Katsuo
导致板状伪足形成的 WAVE2 的膜运输需要小型 GTP 酶 Rac1、运动蛋白驱动蛋白和微管。在这里，我们探讨了 Rac1 依赖性和驱动蛋白介导的 WAVE2 沿着微管的运输是否受到作为 Rac1 下游效应器的 p21 激活激酶 Pak 调节的可能性。我们发现 Pak1 与 WAVE2 组成型结合，并通过肝细胞生长因子 (HGF) 刺激与 WAVE2 一起转运至前缘。同时，诱导了微管蛋白结合的 stathmin/Op18 在丝氨酸 25 (Ser25) 和 Ser38 处的磷酸化、微管生长以及 stathmin/Op18 与驱动蛋白-WAVE2 复合物的结合。 Pak1 抑制剂 IPA-3 和小干扰 RNA (siRNA) 消除 Pak1 可以消除 HGF 诱导的 WAVE2 转运、片状伪足形成、Stathmin/Op18 Ser38 磷酸化以及与驱动蛋白-WAVE2 复合物的结合，但不能消除 Stathmin/Cp18 Ser25 磷酸化和微管生长。此外，用siRNA去除stathmin/Op18会显着抑制HGF诱导的WAVE2转运和片状伪足形成，并独立于HGF促进微管生长。总的来说，Pak1 在 HGF 诱导的 WAVE2 转运和板状伪足形成中发挥着关键作用，通过磷酸化和微管蛋白结合的 stathmin/Op18 向复合物的募集，将 Pak1-WAVE2-驱动蛋白复合物导向生长的微管末端。 (C) 2009 Elsevier Inc. 保留所有权利。
Membrane transport of WAVE2 that leads to lamellipodia formation requires a small GTPase Rac1, the motor protein kinesin, and microtubules. Here we explore the possibility of whether the Rac1-dependent and kinesin-mediated WAVE2 transport along microtubules is regulated by a p21-activated kinase Pak as a downstream effector of Rac1. We find that Pak1 constitutively binds to WAVE2 and is transported with WAVE2 to the leading edge by stimulation with hepatocyte growth factor (HGF). Concomitantly, phosphorylation of tubulin-bound stathmin/Op18 at serine 25 (Ser25) and Ser38, microtubule growth, and stathmin/Op18 binding to kinesin-WAVE2 complex were induced. The HGF-induced WAVE2 transport, lamellipodia formation, stathmin/Op18 phosphorylation at Ser38 and binding to kinesin-WAVE2 complex, but not stathmin/Cp18 phosphorylation at Ser25 and microtubule growth, were abrogated by Pak1 inhibitor IPA-3 and Pak1 depletion with small interfering RNA (siRNA). Moreover, stathmin/Op18 depletion with siRNA caused significant inhibition of HGF-induced WAVE2 transport and lamellipodia formation, with HGF-independent promotion of microtubule growth. Collectively, it is suggested that Pak1 plays a critical role in HGF-induced WAVE2 transport and lamellipodia formation by directing Pak1-WAVE2-kinesin complex toward the ends of growing microtubules through phosphorylation and recruitment of tubulin-bound stathmin/Op18 to the complex. (C) 2009 Elsevier Inc. All rights reserved.