Stemcell, 100-1795, Human/Mouse/Rat Recombinant Follistatin-Resistant Activin A, ACF

Follistatin-resistant activin A (FRACTA) is a modified version of Activin A that has been engineered to reduce binding to follistatin, the natural inhibitor of Activin A. Activin A is a member of the transforming growth factor beta (TGF-β) family of proteins produced by many cell types throughout development (Gurdon et al.). It is a disulfide-linked homodimer (two beta-A chains) that binds to heteromeric complexes of a type I (Act RI-A and Act RI-B) and a type II (Act RII-A and Act RII-B) serine-threonine kinase receptor (Attisano et al.). Activins primarily signal through SMAD2/3 proteins to regulate a variety of functions, including cell proliferation, differentiation, wound healing, apoptosis, and metabolism (McDowell et al.). Activin A signaling is regulated by binding of follistatin, which blocks the type-II receptor binding site (Harrington et al.). Activin A maintains the undifferentiated state of human embryonic stem cells (James et al.; Xiao et al.) and also facilitates differentiation of human embryonic stem cells into definitive endoderm (D’Amour et al.). This product is animal component-free (ACF).