Members of the transforming growth factor b superfamily bind to a pair of transmembrane proteins, known as receptor types I and II, which contain serine/threonine kinases and associate to form a signaling complex (1). Activin has been shown to bind a heteromeric noncovalent complex, which consists of a type I receptor, ACTR-IA (also designated ACVRI and ALK-2) or ACTR-IB (also designated ALK-4 and SKR2), and a type II receptor, ACTR-IIA (also designated ACVR2A) or ACTR-IIB (also designated ACVR2B) (1â€"6). Both receptor types are highly expressed in brain (5). The activin receptor family members are thought to mediate distinct effects on gene expression, cell differentiation, and morpho- genesis in a dose dependent fashion (5,6).
Subcellular location: Extracellular
Synonyms: Activin Receptor Type IA, Activin A receptor type I, Activin A receptor type II like kinase 2, Activin receptor type I, Activin receptor type-1, Activin receptor-like kinase 2, ACTR1, ACTR 1, ACTR-1, ACTR-I, ACTRI, ACVR 1, ACVR1, ACVR1_HUMAN, ACVR1A, ACVRLK 2, ACVRLK2, ALK 2, ALK-2, ALK2, FOP, Hydroxyalkyl protein kinase, Serine/threonine protein kinase receptor R1, Serine/threonine-protein kinase receptor R1, SKR 1, SKR1, TGF-B superfamily receptor type I, TGFB superfamily receptor type I, TSR-I, TSRI, TSRI.