Pyk2 Activation Triggers Epidermal Growth Factor Receptor Signaling and Cell Motility after Wounding Sheets of Epithelial Cells
Pyk2 Activation Triggers Epidermal Growth Factor Receptor Signaling and Cell Motility after Wounding Sheets of Epithelial Cells
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DOI：
10.1074/jbc.m109.083089
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发表时间：
2010-04-30
影响因子：
4.8
通讯作者：
Klarlund, Jes K.
中科院分区：
文献类型：
--
作者：
Block, Ethan R.;Tolino, Michael A.;Klarlund, Jes K.
表皮生长因子受体（EGFR）的激活是促进细胞移动并覆盖许多上皮中的伤口的关键信号事件。我们先前已经表明，创伤通过激活Src家族激酶（SFK）激活EGFR，其诱导表皮生长因子样配体从细胞表面的蛋白水解脱落。伤口愈合研究的一个主要目标是识别促进运动的早期信号，在这里，我们研究了这样一个假设，即粘着斑激酶家族的成员是创伤后SFKs的上游激活剂。我们发现，粘着斑激酶不会被创伤激活，但不同的家族成员Pyk 2（PTK 2B/RAFTK/CAK β）被快速有效地激活。Pyk 2与c-Src的相互作用在创伤后增加，如通过免疫共沉淀实验所确定的。通过小干扰RNA或显性负突变体的表达破坏Pyk 2信号传导导致抑制SFK和EGFR的伤口诱导的活化，并且相反，野生型Pyk 2的过表达刺激细胞中的SFK和EGFR激酶活性。在伤口愈合研究中，Pyk 2小干扰RNA或显性阴性抑制细胞迁移。这些结果表明，Pyk 2的激活是通过刺激SFK/EGFR信号通路促进伤口愈合的早期信号。
Activation of the epidermal growth factor receptor (EGFR) is a key signaling event that promotes cells to move and cover wounds in many epithelia. We have previously shown that wounding activates the EGFR through activation of the Src family kinases (SFKs), which induce proteolytic shedding of epidermal growth factor-like ligands from the cell surface. A major goal in wound healing research is to identify early signals that promote motility, and here we examined the hypothesis that members of the focal adhesion kinase family are upstream activators of the SFKs after wounding. We found that focal adhesion kinase is not activated by wounding but that a different family member, Pyk2 (PTK2B/RAFTK/CAK beta), is activated rapidly and potently. Pyk2 interaction with c-Src is increased after wounding, as determined by co-immunoprecipitation experiments. Disruption of Pyk2 signaling either by small interfering RNA or by expression of a dominant negative mutant led to inhibition of wound-induced activation of the SFKs and the EGFR, and conversely, overexpression of wild-type Pyk2 stimulated SFK and EGFR kinase activities in cells. In wound healing studies, Pyk2 small interfering RNA or dominant negative inhibited cell migration. These results show that activation of Pyk2 is an early signal that promotes wound healing by stimulating the SFK/EGFR signaling pathway.