Smad在TGF-β超家族信号通路中的调控作用

TGF-β Superfamily Signaling Pathway

TGF家族蛋白在哺乳动物的器官发育及形成中起着重要作用 ,它们经过膜受体的介导将信号传入细胞内 ,其下游最主要的调控蛋白Smad在胞内通过不同的调节各种基因的表达 ,这些模式主要有R Smad Smad 4复合物直接与DNA结合 ,Smad蛋白与其他DNA结合因子 ,Smad蛋白与非DNA结合因子间的相互作用。Smad在BMPs对成骨细胞的分化调节过程中与Ras MAPK AP 1通路关联 。

TGF β superfamily play a role in different developmental processes, they transduce the signal into cell by membranous receptor, the main downstream protein Smad regulate the expression of various genes by different modes,including direct DNA binding by the R Smad/Smad4 complex and interaction of Smad proteins with other DNA binding and non DNA binding transcriptional activator and repressor components. BMP 2 activates not only the Smad signaling, but also the Ras/MAPK/AP 1 pathway. The net effect of these two factors on gene expression depends on the intricate balance of these two signal transduction pathways.