AUTOPHOSPHORYLATION OF THE FOCAL ADHESION KINASE, PP125(FAK), DIRECTS SH2 DEPENDENT BINDING OF PP60(SRC)
AUTOPHOSPHORYLATION OF THE FOCAL ADHESION KINASE, PP125(FAK), DIRECTS SH2 DEPENDENT BINDING OF PP60(SRC)
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DOI：
10.1128/mcb.14.3.1680
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发表时间：
1994-03-01
影响因子：
5.3
通讯作者：
PARSONS, JT
中科院分区：
文献类型：
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作者：
SCHALLER, MD;HILDEBRAND, JD;PARSONS, JT
酪氨酸残基上的蛋白酪氨酸激酶（PTKs）的磷酸化是调节催化活性并触发PTKs与含Src同源性2（SH 2）的蛋白的物理缔合的关键调节事件。整合素连接的粘着斑激酶ppl 25（FAK）表现出对酪氨酸的细胞外基质依赖性磷酸化，并通过其SH 2结构域与两种非受体PTK pp 6 O（src）和pp 59（fyn）物理缔合。在此，我们确定Tyr-397为体内和体外ppl 25（FAK）上酪氨酸磷酸化的主要位点。酪氨酸397位于N-末端和催化结构域的交界处，是PTK自磷酸化的新位点。Tyr-397突变为不可磷酸化的残基在体内和体外显著损害ppl 25（FAK）对酪氨酸的磷酸化。Tyr-397到Phe的突变还抑制了在表达Src和FAK（397 F）的细胞中与pp 60（src）形成稳定的复合物，这表明pp 125（FAK）的自磷酸化可以调节pp 125（FAK）与Src家族激酶的体内缔合。Tyr-397作为FAK自磷酸化的主要位点的鉴定提供了含有Src家族激酶SH 2结构域的高亲和力结合位点的细胞蛋白的第一个实例之一。这一发现对描述pp 125（FAK）的作用机制、Src家族PTKs的调节以及通过整合素的信号转导的模型具有影响。
The phosphorylation of protein tyrosine kinases (PTKs) on tyrosine residues is a critical regulatory event that modulates catalytic activity and triggers the physical association of PTKs with Src homology 2 (SH2)-containing proteins. The integrin-linked focal adhesion kinase, ppl25(FAK), exhibits extracellular matrix-dependent phosphorylation on tyrosine and physically associates with two nonreceptor PTKs, pp6O(src) and pp59(fyn), via their SH2 domains. Herein, we identify Tyr-397 as the major site of tyrosine phosphorylation on ppl25(FAK) both in vivo and in vitro. Tyrosine 397 is located at the juncture of the N-terminaI and catalytic domains, a novel site for PTK autophosphorylation. Mutation of Tyr-397 to a nonphosphorylatable residue dramatically impairs the phosphorylation of ppl25(FAK) on tyrosine in vivo and in vitro. The mutation of Tyr-397 to Phe also inhibits the formation of stable complexes with pp60(src) in cells expressing Src and FAK(397F) suggesting that autophosphorylation of ppl25(FAK) may regulate the association of pp125(FAK) with Src family kinases in vivo. The identification of Tyr-397 as a major site for FAK autophosphorylation provides one of the first examples of a cellular protein containing a high-affinity binding site for a Src family kinase SH2 domain. This finding has implications for models describing the mechanisms of action of pp125(FAK), the regulation of the Src family of PTKs, and signal transduction through the integrins.