Wang Chau-Zen, Su Hsiao-Wen, Hsu Yu-Chih, Shen Meng-Ru, Tang Ming-Jer
Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 701, Taiwan.
Mol Biol Cell. 2006 Jun;17(6):2839-52. doi: 10.1091/mbc.e05-11-1068. Epub 2006 Apr 12.
Regulation of cell migration is an important step for the development of branching tubule morphogenesis in collagen gel. Here, we showed that discoidin domain receptor (DDR) 1a/b inhibited collagen-induced tyrosine phosphorylation of signal transducers and activators of transcription (Stat) 1/3 and cell migration triggered by alpha2beta1-integrin. Overexpression of DDR1a/b increased the interaction of DDR1 with SHP-2 and up-regulated the tyrosine phosphatase activity of SHP-2. Expression of catalytically inactive SHP-2 in DDR1-transfected cells restored the tyrosine phosphorylation of Stat3 and cell migration. We demonstrated that the Src homology-2 (SH2)-SH2 and phosphotyrosyl phosphatase (PTP) domains of SHP-2 were responsible for interaction with DDR1 and that both tyrosine phosphorylation sites 703 and 796 of DDR1 were essential for it to bind with SHP-2. Mutation of tyrosine 703 or 796 of DDR1 abolished the ability of DDR1 to inhibit the tyrosine phosphorylation of Stat1 and Stat3 and restored collagen-induced cell migration and hepatocyte growth factor-induced branching tubulogenesis in collagen gel. Together, these results demonstrate that SHP-2 is required for the DDR1-induced suppression of Stat1 and Stat3 tyrosine phosphorylation, cell migration, and branching tubulogenesis.
细胞迁移的调控是胶原凝胶中分支小管形态发生发展的重要步骤。在此,我们表明盘状结构域受体(DDR)1a/b抑制胶原诱导的信号转导子和转录激活子(Stat)1/3的酪氨酸磷酸化以及α2β1整合素触发的细胞迁移。DDR1a/b的过表达增加了DDR1与SHP-2的相互作用,并上调了SHP-2的酪氨酸磷酸酶活性。在DDR1转染细胞中表达无催化活性的SHP-2可恢复Stat3的酪氨酸磷酸化和细胞迁移。我们证明SHP-2的Src同源2(SH2)-SH2和磷酸酪氨酸磷酸酶(PTP)结构域负责与DDR1相互作用,并且DDR1的酪氨酸磷酸化位点703和796对于其与SHP-2结合都至关重要。DDR1的酪氨酸703或796突变消除了DDR1抑制Stat1和Stat3酪氨酸磷酸化的能力,并恢复了胶原诱导的细胞迁移以及肝细胞生长因子诱导的胶原凝胶中的分支小管形成。总之,这些结果表明SHP-2是DDR1诱导的Stat1和Stat3酪氨酸磷酸化抑制、细胞迁移和分支小管形成所必需的。