Hocevar B A, Smine A, Xu X X, Howe P H
Department of Cell Biology, The Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
EMBO J. 2001 Jun 1;20(11):2789-801. doi: 10.1093/emboj/20.11.2789.
Using a genetic complementation approach we have identified disabled-2 (Dab2), a structural homolog of the Dab1 adaptor molecule, as a critical link between the transforming growth factor beta (TGFbeta) receptors and the Smad family of proteins. Expression of wild-type Dab2 in a TGFbeta-signaling mutant restores TGFbeta-mediated Smad2 phosphorylation, Smad translocation to the nucleus and Smad-dependent transcriptional responses. TGFbeta stimulation triggers a transient increase in association of Dab2 with Smad2 and Smad3, which is mediated by a direct interaction between the N-terminal phosphotyrosine binding domain of Dab2 and the MH2 domain of Smad2. Dab2 associates with both the type I and type II TGFbeta receptors in vivo, suggesting that Dab2 is part of a multiprotein signaling complex. Together, these data indicate that Dab2 is an essential component of the TGFbeta signaling pathway, aiding in transmission of TGFbeta signaling from the TGFbeta receptors to the Smad family of transcriptional activators.
我们采用基因互补方法鉴定出disabled-2(Dab2),它是衔接分子Dab1的结构同源物,是转化生长因子β(TGFβ)受体与Smad蛋白家族之间的关键连接分子。在TGFβ信号转导突变体中表达野生型Dab2可恢复TGFβ介导的Smad2磷酸化、Smad转位至细胞核以及Smad依赖的转录反应。TGFβ刺激引发Dab2与Smad2和Smad3结合的短暂增加,这是由Dab2的N端磷酸酪氨酸结合结构域与Smad2的MH2结构域之间的直接相互作用介导的。Dab2在体内与I型和II型TGFβ受体均相关联,表明Dab2是多蛋白信号复合物的一部分。这些数据共同表明,Dab2是TGFβ信号通路的重要组成部分,有助于将TGFβ信号从TGFβ受体传递至转录激活因子Smad家族。