Tks5 recruits AFAP-110, p190RhoGAP, and cortactin for podosome formation
Tks5 recruits AFAP-110, p190RhoGAP, and cortactin for podosome formation
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DOI：
10.1016/j.yexcr.2009.06.012
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发表时间：
2009-09-10
影响因子：
3.7
通讯作者：
Gimona, Mario
中科院分区：
文献类型：
--
作者：
Crimaldi, Luca;Courtneidge, Sara A.;Gimona, Mario
血管平滑肌细胞中的足状体形成的特征在于AFAP-110、p190 RhoGAP和corneum的募集，它们分别在Src激活、RhoA活性的局部下调和肌动蛋白聚合中具有特定作用。然而，其特异性募集到足体的分子机制仍然未知。支架蛋白Tks 5定位于Src转化的成纤维细胞和平滑肌细胞中的podosome，并且可以在podosome形成期间作为各种组分的特异性募集衔接子。我们在这里表明，诱导的TKS 5的线粒体表面的错误定位，导致一个主要的亚细胞重新分布的AFAP-110，p190 RhoGAP，和corneum，并抑制足状体的形成。一系列类似的错误的Tks 5缺失突变体的分析表明，第五SH 3结构域是必不可少的招聘。缺乏PX结构域的Tks 5突变体也抑制了podosome的形成，并诱导AFAP-110、p190 RhoGAP和corneum重新分布到核周区。通过表达无催化活性的点突变体和通过siRNA介导的表达敲低，我们还提供了p190 RhoGAP是podosome形成所需的证据。总之，我们的研究结果表明，Tks 5在招募AFAP-110，p190 RhoGAP和corneum来驱动podosome形成中起着核心作用。(C)2009 Elsevier Inc. All rights reserved.
Podosome formation in vascular smooth muscle cells is characterized by the recruitment of AFAP-110, p190RhoGAP, and cortactin, which have specific roles in Src activation, local down-regulation of RhoA activity, and actin polymerization, respectively. However, the molecular mechanism that underlies their specific recruitment to podosomes remains unknown. The scaffold protein Tks5 is localized to podosomes in Src-transformed fibroblasts and in smooth muscle cells, and may serve as a specific recruiting adapter for various components during podosome formation. We show here that induced mislocalization of Tks5 to the surface of mitochondria leads to a major subcellular redistribution of AFAP-110, p190RhoGAP, and cortactin, and to inhibition of podosome formation. Analysis of a series of similarly mistargeted deletion mutants of Tks5 indicates that the fifth SH3 domain is essential for this recruitment. A Tks5 mutant lacking the PX domain also inhibits podosome formation and induces the redistribution of AFAP-110, p190RhoGAP, and cortactin to the perinuclear area. By expressing a catalytically inactive point mutant and by siRNA-mediated expression knock-down we also provide evidence that p190RhoGAP is required for podosome formation. Together our findings demonstrate that Tks5 plays a central role in the recruitment of AFAP-110, p190RhoGAP, and cortactin to drive podosome formation. (C) 2009 Elsevier Inc. All rights reserved.