Pressure activates colon cancer cell adhesion via paxillin phosphorylation, Crk, Cas, and Rac1
Pressure activates colon cancer cell adhesion via paxillin phosphorylation, Crk, Cas, and Rac1
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DOI：
10.1007/s00018-008-8038-x
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发表时间：
2008-05-01
影响因子：
8
通讯作者：
Basson, M. D.
中科院分区：
文献类型：
--
作者：
Downey, C.;Craig, D. H.;Basson, M. D.
物理力可以激活结肠癌细胞粘附，对转移至关重要。Paxillin被FAK磷酸化，是压力刺激粘附所必需的。然而，paxillin是否作为惰性支架蛋白或是否需要paxillin磷酸化尚不清楚。转染paxillin点磷酸化突变体表明，酪氨酸31和118位点的磷酸化对于压力刺激的粘附是必要的。我们进一步评估了潜在的帕罗西林合作伙伴。降低接头蛋白Crk或黏附蛋白p130（Cas）阻断压力刺激的黏附。此外，除了转染了Y31Y118 paxillin突变体的细胞外，Crk和p130（Cas）都表现出与paxillin共同免疫沉淀的增加，以响应压力的增加。抑制小GTPase Rac1也消除了压力刺激的粘附，siRNA还原paxillin阻断了压力作用下的Rac1磷酸化。因此，帕西林酪氨酸31和118位点的磷酸化对于压力诱导的粘附是必要的。Paxillin， Crk和Cas形成一个三聚体复合物，激活Rac1并介导这种作用。
Physical forces can activate colon cancer cell adhesion, critical for metastasis. Paxillin is phosphorylated by FAK and required for pressure-stimulated adhesion. However, whether paxillin acts as an inert scaffolding protein or whether paxillin phosphorylation is required is unknown. Transfection with paxillin point-phosphorylation mutants demonstrated that phosphorylation at tyrosines 31 and 118 together is necessary for pressure-stimulated adhesion. We further evaluated-potential paxillin partners. Reducing the adaptor protein Crk or the focal adhesion protein p130(Cas) blocked pressure-stimulated adhesion. Furthermore, Crk and p130(Cas) both displayed increased co-immunoprecipitation with paxillin in response to increased pressure, except in cells transfected with a Y31Y118 paxillin mutant. Inhibiting the small GTPase Rac1 also abolished pressure-stimulated adhesion, and reducing paxillin by siRNA blocked Rac1 phosphorylation by pressure. Thus, paxillin phosphorylation at tyrosines 31 and 118 together is necessary for pressure-induced adhesion. Paxillin, Crk and Cas form a trimeric complex that activates Rac1 and mediates this effect.