骨形态发生蛋白的受体及其信号传递过程

Bone Morphogenetic Protein Receptor and Signal Transduction.

近年来已克隆出几种Ⅰ型和Ⅱ型ＢＭＰ受体．ＢＭＰ受体属于ＴＧＦβ受体超家族的成员，具有丝氨酸／苏氨酸蛋白激酶活性．Ⅰ型与Ⅱ型ＢＭＰ受体均可与ＢＭＰ配基结合，但若执行传递信号功能，两受体需首先形成复合物．删除突变和基因剔除研究证明，ⅠＡ型ＢＭＰ受体对动物的中胚层发育至关重要．而ⅠＢ型ＢＭＰ受体在软骨细胞形成、成骨细胞分化以及程序化细胞死亡方面起主要作用．ＢＭＰ受体信号传递分子Ｓｍａｄ１和Ｓｍａｄ５也已被克隆和鉴定。

Recently, several bone morphogenetic protein (BMP) receptors (ⅠA, ⅠB and Ⅱ) have been cloned and characterized. BMP receptors belong to the TGFβ receptors family of serine/threonine kinases . Both typeⅠ and typeⅡ BMP receptors bind BMP ligands, in order to elicit a signal, heteromeric complexes of typeⅠ and typeⅡ receptors are required . Using truncated and constitutively active BMP receptors, it has been shown that type ⅠA BMP receptor plays important role in mesoderm formation in vivo . Type ⅠB BMP receptor plays major roles in chondrogenesis, osteoblast differentiation and programmed cell death in vivo and in vitro . BMP receptor signaling molecules Smad1 and Smad5 are also cloned and characterized. They also play important roles in BMP receptor mediated function.