Activin A, Human

Activin-A, a member of the TGF-beta superfamily, has fundamental roles in embryonic development, stem cell maintenance and differentiation, haematopoiesis, cell proliferation, and tissue fibrosis. It signals through two type I and two type II receptors, activating kinase activity, phosphorylating SMAD2 and 3 intracellular signaling mediators, forming a complex with SMAD4, and translocating to the nucleus to regulate gene expression.