转化生长因子-β族信号的转导

Signal Transduction of Transforming Growth Factor-β Family.

TGF β族细胞因子通过各自信号转导产生多种生物学效应 ,其基本过程是 :信号沿TGF β族配体→受体→SMAD蛋白→转录因子→DNA表达的次序转导 .在TGF β族各因子刺激各自具有蛋白激酶活性的两型膜受体时 ,各因子先结合Ⅱ型受体 ,结合配体的Ⅱ型受体再激活Ⅰ型受体 .活化的I型受体磷酸化通路特异性SMAD ,后者与公用性SMAD结合后从胞浆移至核内 ,核内SMAD通过与转录因子结合和直接与DNA结合调节基因的表达 .

Cytokines of the TGF β family exert multiple biological effects by their signal transduction pathways that undergo a basic course as follows: ligands of TGF β family→receptors→SMADs→ transcription factors→DNA expression. In stimulating their own two type receptors with kinase activity the cytokines first bind to type Ⅱ receptors and then the ligand binding type Ⅱ receptors activate type Ⅰ receptors. The type Ⅰ receptors phosphorylate pathway specific SMADs. These activated SMADs then associate with common SMAD and translocate from cytoplasm to nucleus where they regulate transcription either by associating with transcription factors and by binding directly to DNA.