Interaction of p190RhoGAP with C-terminal Domain of p120-catenin Modulates Endothelial Cytoskeleton and Permeability
Interaction of p190RhoGAP with C-terminal Domain of p120-catenin Modulates Endothelial Cytoskeleton and Permeability
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DOI：
10.1074/jbc.m112.432757
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发表时间：
2013-06-21
影响因子：
4.8
通讯作者：
Birukov, Konstantin G.
中科院分区：
文献类型：
--
作者：
Zebda, Noureddine;Tian, Yufeng;Birukov, Konstantin G.
p120-catenin是一种多结构域细胞内蛋白，其介导许多细胞功能，包括细胞-细胞跨膜钙粘蛋白复合物的稳定以及通过调节小GTPAes的活性来调节与屏障功能、板状伪足形成和细胞迁移相关的肌动蛋白动力学。一种机制涉及p120连环蛋白与Rho GTP酶激活蛋白（p190 RhoGAP）的相互作用，导致p190 RhoGAP募集到细胞外周并局部抑制Rho活性。在这项研究中，我们已经确定了一段23个氨基酸的C-末端结构域的p120连环蛋白作为最小的序列负责招聘的p190 RhoGAP（在此称为CRAD;连环蛋白-RhoGAP协会域）。在内皮细胞中缺乏CRAD的p120-连环蛋白截短突变体的表达减弱了屏障保护性氧化磷脂OxPAPC的作用。这种作用伴随着抑制p190 RhoGAP的膜转位，增加Rho信号，以及抑制Rac 1及其细胞骨架效应因子PAK 1（p21激活激酶1）和corpine的激活。缺乏CRAD的p120连环蛋白截短突变体的表达也延迟了凝血酶诱导的内皮屏障破坏后的恢复过程。同时，RhoA激活和下游信号传导持续较长的时间，而Rac信号传导被抑制。这些数据表明，p120-catenin（氨基酸820-843）结构域在p120-catenin p 190 RhoGAP信号复合物组装、膜靶向和刺激p190 RhoGAP活性以抑制Rho途径和相互上调Rac信号传导中发挥着关键作用对于内皮屏障调节至关重要。
p120-catenin is a multidomain intracellular protein, which mediates a number of cellular functions, including stabilization of cell-cell transmembrane cadherin complexes as well as regulation of actin dynamics associated with barrier function, lamellipodia formation, and cell migration via modulation of the activities of small GTPAses. One mechanism involves p120 catenin interaction with Rho GTPase activating protein (p190RhoGAP), leading to p190RhoGAP recruitment to cell periphery and local inhibition of Rho activity. In this study, we have identified a stretch of 23 amino acids within the C-terminal domain of p120 catenin as the minimal sequence responsible for the recruitment of p190RhoGAP (herein referred to as CRAD; catenin-RhoGAP association domain). Expression of the p120-catenin truncated mutant lacking the CRAD in endothelial cells attenuated effects of barrier protective oxidized phospholipid, OxPAPC. This effect was accompanied by inhibition of membrane translocation of p190RhoGAP, increased Rho signaling, as well as suppressed activation of Rac1 and its cytoskeletal effectors PAK1 (p21-activated kinase 1) and cortactin. Expression of p120 catenin-truncated mutant lacking CRAD also delayed the recovery process after thrombin-induced endothelial barrier disruption. Concomitantly, RhoA activation and downstream signaling were sustained for a longer period of time, whereas Rac signaling was inhibited. These data demonstrate a critical role for p120-catenin (amino acids 820-843) domain in the p120-cateninp 190RhoGAP signaling complex assembly, membrane targeting, and stimulation of p190RhoGAP activity toward inhibition of the Rho pathway and reciprocal up-regulation of Rac signaling critical for endothelial barrier regulation.