Activin A is a TGFβ family growth factor used frequently for the maintenance of pluripotency in induced pluripotent stem cell (iPSC) and embryonic stem cell (ESC) culture. Activin A is a homodimer of two beta A chains and is not biologically active until the N terminal propeptide is cleaved from each. Activins interact with Type I and Type II serine/threonine kinases to signal to SMAD proteins to regulate a variety of functions, including cell proliferation, differentiation, wound healing, apoptosis, metabolism, etc.
