Differential signaling by the focal adhesion kinase and cell adhesion kinase beta
Differential signaling by the focal adhesion kinase and cell adhesion kinase beta
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DOI：
10.1074/jbc.272.40.25319
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发表时间：
1997-10-03
影响因子：
4.8
通讯作者：
Sasaki, T
中科院分区：
文献类型：
--
作者：
Schaller, MD;Sasaki, T
pp 125（FAK）和CAK β/Pyk 2/CadTK/RAFTK是相关的蛋白酪氨酸激酶。因此，CAK β是否具有pp 125（FAK）的一些特性是令人感兴趣的。使用重组谷胱甘肽S-转移酶融合蛋白，我们表明，这两种蛋白质的C-末端结构域结合桩蛋白在体外。CAK β的C-末端结构域被设计成在鸡胚细胞中自主表达，并且与pp 125（FAK）和p41/43（FRNK）（pp 125（FAK）的C-末端非催化结构域）一样，被发现定位于细胞粘着斑。相反，全长CAK β通常被发现弥漫性分布在整个细胞中，尽管一部分细胞表现出粘着斑定位。钒酸盐处理pp 125（FAK）和CAK β过表达的CE细胞诱导了一组常见蛋白质（包括张力蛋白、桩蛋白和p130（Cas））磷酸酪氨酸含量的显著增加，但其中一些底物，特别是p130（Cas），似乎被pp 125（FAK）和CAK β差异磷酸化。酪氨酸磷酸化水平较高的CAK β过表达细胞，和其他磷酸酪氨酸的物种特异性免疫沉淀，此外，钒酸盐处理CE细胞过表达CAK β，但不pp 125（FAK）过表达，诱导了深刻的形态学变化，这可能是一个结果，观察到的底物磷酸化的差异。
pp125(FAK) and CAK beta/Pyk2/CadTK/RAFTK are related protein-tyrosine kinases. It is therefore of interest whether CAK beta shares some of the properties of pp125(FAK). Using recombinant glutathione S-transferase fusion proteins, we show that the C-terminal domains of both proteins bind paxillin in vitro. The C-terminal domain of CAK beta was engineered to be autonomously expressed in chicken embryo cells and, like pp125(FAK) and p41/43(FRNK) (the C-terminal noncatalytic domain of pp125(FAK)) was found to localize to cellular focal adhesions. In contrast, full-length CAK beta was generally found diffusely distributed throughout the cell, although a fraction of the cells exhibited focal adhesion localization. Vanadate treatment of pp125(FAK) and CAK beta-overexpressing CE cells induced a dramatic increase in the phosphotyrosine content of a common set of proteins including tensin, paxillin, and p130(Cas), but some of these substrates, particularly p130(Cas), appeared to be differentially phosphorylated by pp125(FAK) and CAK beta. Levels of tyrosine phosphorylation were higher in CAK beta-overexpressing cells, and additional phosphotyrosine-containing species were specifically immunoprecipitated, In addition, vanadate treatment of CE cells overexpressing CAK beta, but not pp125(FAK) overexpressors, induced a profound morphological change, which could be a consequence of the observed differences in substrate phosphorylation.