Smad及其结合蛋白在TGFβ信号传导中的功能

Functions of Smad and Its Binding Proteins in TGF β Signal Pathway

转化生长因子β超家族的细胞因子在细胞生长发育和分化、物质代谢等方面都有极其重要的作用,这种多功效性决定在细胞内必然存在复杂的TGF β信号传导通路。Smad是TGF β超家族信号传导的下游因子,介导TGF β信号从胞质中传入细胞核,特异性调节TGF β靶基因的表达。最近的研究发现与Smad结合的蛋白因子,包括转录因子、活化因子和抑制因子等在Smad特异性识别和调控TGF β靶基因表达的过程中起着十分重要的作用。同时,Smad通过与不同蛋白因子相结合形成复合体调控TGF β靶基因的表达可能是TGF β具有多种生物学功能的分子基础。

Members of transforming growth factor-β (TGF β) superfamily play an important roles in regulating cell growth,differentiation and tissue homeostasis. The multi-functional roles of TGF β are performed by phosphorylating their downstream factor Smad. It has been recently reported that Smad can physically associate with different cy-tosolic protein factors,such as transcription factors,coactivators and corepressors. In the TGF β signal transduction pathways,the activated Smad directively interact with those factors to form different Smad/factors complexes which are then translocated from cytoplasm to nucleus where they regulate different TGF β responsive gene expression for its mutifunctional roles in cells.