Hepatocyte growth factor induces ERK-dependent paxillin phosphorylation and regulates paxillin-focal adhesion kinase association
Hepatocyte growth factor induces ERK-dependent paxillin phosphorylation and regulates paxillin-focal adhesion kinase association
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DOI：
10.1074/jbc.m107551200
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发表时间：
2002-03-22
影响因子：
4.8
通讯作者：
Cantley, LG
中科院分区：
文献类型：
--
作者：
Liu, ZX;Yu, CF;Cantley, LG
肝细胞生长因子（HGF）调节培养的上皮细胞中的细胞粘附、迁移和分支形态发生，这些事件需要调节细胞-基质相互作用。本研究以mIMCD-3上皮细胞为研究对象，研究了HGF对粘着斑蛋白、粘着斑激酶（FAK）和桩蛋白的影响及其相互关系。发现HGF增加桩蛋白的酪氨酸磷酸化，并在较小程度上增加FAK。此外，HGF诱导桩蛋白和活化的ERK的关联，与用ERK抑制剂U 0126防止的桩蛋白的凝胶阻滞相关。在全长和氨基末端桩蛋白中，激活的ERK磷酸化和诱导桩蛋白凝胶阻滞的能力在体外得到证实。桩蛋白中几个潜在的ERK磷酸化位点位于桩蛋白-FAK结合结构域的侧翼，因此检测了HGF调节桩蛋白-FAK结合的能力。HGF诱导桩蛋白-FAK结合增加，U 0126预处理可抑制该结合，并通过ERK体外磷酸化桩蛋白重现。预防FAR-桩蛋白与U 0126的结合与抑制HGF介导的FAK酪氨酸磷酸化和抑制HGF依赖性细胞扩散和粘附相关。FAK和桩蛋白的细胞定位的检查表明，肝细胞生长因子引起的凝聚的粘着斑复合物在细胞过程的前沿和FAK-桩蛋白共定位在这些大的复合物。因此，这些数据表明，HGF可以诱导桩蛋白的丝氨酸/苏氨酸磷酸化，最有可能直接由ERK介导，导致FAK的募集和激活以及随后的细胞铺展和粘附的增强。
Hepatocyte growth factor (HGF) modulates cell adhesion, migration, and branching morphogenesis in cultured epithelial cells, events that require regulation of cell-matrix interactions. Using mIMCD-3 epithelial cells, we studied the effect of HGF on the focal adhesion proteins, focal adhesion kinase (FAK) and paxillin and their association. HGF was found to increase the tyrosine phosphorylation of paxillin and to a lesser degree FAK. In addition, HGF induced association of paxillin and activated ERK, correlating with a gel retardation of paxillin that was prevented with the ERK inhibitor U0126. The ability of activated ERK to phosphorylate and induce gel retardation of paxillin was confirmed in vitro in both full-length and amino-terminal paxillin. Several potential ERK phosphorylation sites in paxillin flank the paxillin-FAK association domains, so the ability of HGF to regulate paxillin-FAK association was examined. HGF induced an increase in paxillin-FAK association that was inhibited by pretreatment with U0126 and reproduced by in vitro phosphorylation of paxillin with ERK. The prevention of the FAR-paxillin association with U0126 correlated with an inhibition of the HGF-mediated FAK tyrosine phosphorylation and inhibition of HGF-dependent cell spreading and adhesion. An examination of cellular localization of FAK and paxillin demonstrated that HGF caused a condensation of focal adhesion complexes at the leading edges of cell processes and FAK-paxillin co-localization in these large complexes. Thus, these data suggest that HGF can induce serine/threonine phosphorylation of paxillin most probably mediated directly by ERK, resulting in the recruitment and activation of FAK and subsequent enhancement of cell spreading and adhesion.