PIAS1-mediated sumoylation of focal adhesion kinase activates its autophosphorylation
PIAS1-mediated sumoylation of focal adhesion kinase activates its autophosphorylation
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DOI：
10.1074/jbc.m308562200
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发表时间：
2003-11-28
影响因子：
4.8
通讯作者：
Girault, JA
中科院分区：
文献类型：
--
作者：
Kadaré, G;Toutant, M;Girault, JA
粘着斑激酶（FAK）是一种富含粘着斑的蛋白酪氨酸激酶，在整合素依赖的细胞运动和存活中起关键作用。其激活的关键步骤是Tyr-397的自磷酸化，其促进包括Src家族激酶在内的几种酶的募集和多种信号通路的激活。我们在酵母双杂交筛选中发现FAK的N端结构域与活化的STAT 1蛋白抑制剂（PIAS 1）相互作用。这种相互作用得到证实，并显示为直接使用体外试验。PIAS 1与来自转染细胞和脑提取物的FAK共免疫沉淀。PIAS 1是一种小的泛素样修饰物（SUMO）连接酶。在PIAS 1和SUMO-1的存在下，FAK在完整细胞中被sumoylated，而PYK 2，一种密切相关的酶，则没有。类小泛素化发生在赖氨酸-152上，这是FAK在进化过程中保守的一个残基。与PIAS 1一样，SUMO化的FAK主要从核组分中回收。SUMO化不需要FAK的催化活性或自身磷酸化。相比之下，在完整细胞和免疫沉淀激酶测定中，苏莫基化显着增加了FAK自磷酸化的能力。内源性FAK在PIAS 1和SUMO-1的存在下独立于细胞粘附被sumoylated，并且sumoylated FAK的自磷酸化在悬浮细胞中持续增加。这些观察结果表明，类小泛素化控制的蛋白激酶的活性，并建议FAK可能在质膜和细胞核之间的信号转导中发挥新的作用。
Focal adhesion kinase (FAK) is a protein tyrosine kinase enriched in focal adhesions, which plays a critical role in integrin-dependent cell motility and survival. The crucial step in its activation is autophosphorylation on Tyr-397, which promotes the recruitment of several enzymes including Src family kinases and the activation of multiple signaling pathways. We found in a yeast two-hybrid screen that the N-terminal domain of FAK interacted with protein inhibitor of activated STAT1 (PIAS1). This interaction was confirmed and shown to be direct using in vitro assays. PIAS1 was co-immunoprecipitated with FAK from transfected cells and brain extracts. PIAS1 has recently been recognized as a small ubiquitin-like modifier ( SUMO) ligase. In the presence of PIAS1 and SUMO-1, FAK was sumoylated in intact cells, whereas PYK2, a closely related enzyme, was not. Sumoylation occurred on Lys-152, a residue conserved in FAK during evolution. Sumoylated FAK, like PIAS1, was recovered predominantly from the nuclear fraction. Sumoylation did not require the catalytic activity or autophosphorylation of FAK. In contrast, sumoylation increased dramatically the ability of FAK to autophosphorylate in intact cells and in immune precipitate kinase assays. Endogenous FAK was sumoylated in the presence of PIAS1 and SUMO-1 independently of cell adhesion, and autophosphorylation of sumoylated FAK was persistently increased in suspended cells. These observations show that sumoylation controls the activity of a protein kinase and suggest that FAK may play a novel role in signaling between the plasma membrane and the nucleus.