TGF- system and its research advances in teleost

Transforming growth factor- (TGF-) family members are multi-functional cytokines, which play pivotal roles in many physiological activities. TGF- is synthesized as a pro-TGF- precursor. Subsequently, the N-terminus of the immature protein is removed, and the new proteins form a homodimer. TGF- mediates its biological functions via binding to receptors TRI and TRII, and then phosphorylates intracellular Smad proteins to activate signal pathway. Till now, most researches in TGF- family are focused on TGF-1, which is involved in immune, reproductive and liver functions, while just few studies about the other members of TGF- and TGF- receptors exist.