Relationship between Smad and transforming growth factor-β signal transduction pathway

Members of transforming growth factor-β(TGF β) superfamily play an important roles in regulating cell growth, differentiation and tissue homeostasis. Smad proteins possess special structure and property and play important roles in transforming growth factor-β(TGF-β) signal transduction pathway. TGF-β activates the downstream Smad proteins,which initiate intracellular signaling pathways via its interaction with TGF-β receptor(TGF-βR) . Research on the varieties,structures and function of Smad proteins,and the complicated regulating mechanism of Smad proteins in TGF-β superfamily signaling transduction are very significative. Key words: Transforming growth factor-β; Smad; Signal transduction