Distinct Activation of Epidermal Growth Factor Receptor by UTP Contributes to Epithelial Cell Wound Repair
Distinct Activation of Epidermal Growth Factor Receptor by UTP Contributes to Epithelial Cell Wound Repair
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DOI：
10.1016/j.ajpath.2010.11.060
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发表时间：
2011-03-01
影响因子：
6
通讯作者：
Trinkaus-Randall, Vickery
中科院分区：
文献类型：
--
作者：
Boucher, Ilene;Kehasse, Amanuel;Trinkaus-Randall, Vickery
损伤后核苷酸的释放激活嘌呤能受体，导致表皮生长因子受体（EGFR）位点特异性残基的磷酸化。为了阐明损伤诱导的反应与外源性EGF诱导的反应之间的差异，我们研究了对接蛋白的募集、EGFR的内化和损伤后的迁移。由抓伤或UTP刺激引起的损伤引起EGFR的短暂内化，这与生长因子受体结合蛋白2 （Grb2）和EGFR磷酸化的较小关联相似。EGF引起的内化持续和检测时间超过60分钟，并与受体磷酸化相关。EGF引起Grb2、磷脂酶c - γ -1 （PLC - γ 1）、Shc和Src向EGFR募集。进行谷胱甘肽s -转移酶下拉实验，发现谷胱甘肽s -转移酶plc γ 1在EGF刺激下与Grb2结合，而在UTP或损伤下不与Grb2结合。此外，UTP不诱导PLC γ - 1磷酸化，EGF诱导的磷酸化在UTP的共刺激下减弱。肝素结合EGF的反应与EGF相当。定点突变表明EGFR的Y1068和Y1086的磷酸化是修复所必需的。总之，我们的研究结果表明，嘌呤能受体的损伤和激活以及通过EGF直接激活EGFR诱导了不同的下游途径。（中华病理学杂志，2011,178:1092-1105;DOI: 10.1016/ j.j ajpath.2010.11.060）
The release of nucleotides after injury activates purinergic receptors, leading to phosphorylation of site-specific residues on epidermal growth factor receptor (EGFR). To elucidate the differences between the injury-induced response and that induced by exogenous EGF, we examined recruitment of docking proteins, internalization of EGFR, and migration after injury. Injury induced by scratch wounds or stimulation by addition of UTP caused a brief internalization of EGFR, which paralleled the lesser association with growth factor receptor-bound protein 2 (Grb2) and phosphorylation of EGFR. The internalization caused by EGF was sustained and detected for longer than 60 minutes and correlated with phosphorylation of the receptor. The EGF caused recruitment of Grb2, phospholipase C-gamma-1 (PLC gamma 1), Shc, and Src to EGFR. Glutathione S-transferase pull downs were performed, and glutathione S-transferase-PLC gamma 1 showed binding of Grb2 when stimulated with EGF but not with UTP or injury. Furthermore, UTP did not induce PLC gamma 1 phosphorylation, and the phosphorylation induced by EGF was attenuated by costimulation with UTP. The response to heparin-binding EGF was equivalent to that of EGF. Site-directed mutagenesis showed that phosphorylation of Y1068 and Y1086 of EGFR is required for repair. Together, our results show that injury and activation of purinergic receptors and direct activation of EGFR via EGF induce distinct downstream pathways. (Am J Pathol 2011, 178:1092-1105; DOI: 10.1016/j.ajpath.2010.11.060)