Activin receptor type-IIA and Activin receptor type-IIB (ACVR2A and ACVR2B)

Activin receptor type-IIA and activin receptor type-IIB are transmembrane serine/threonine kinase receptors that serve as essential components of the TGF-beta superfamily signaling pathways[3][4][5][6]. Both receptors (encoded by ACVR2A and ACVR2B genes) function as type II receptors, forming heteromeric complexes with type I receptors upon ligand binding. This activates downstream SMAD-dependent transcriptional pathways influencing cell proliferation, differentiation, apoptosis, and tissue homeostasis. These receptors are central mediators of activin and myostatin signaling, making them critical regulators of muscle mass, reproductive function, and bone metabolism[3][5][6]. Therapeutic targeting of these receptors—typically by inhibiting activin or myostatin binding—is under clinical and preclinical investigation for muscle-wasting diseases, cancer cachexia, and metabolic disorders. Their broad physiological roles necessitate caution due to potential side effects on other tissues and systems[8][5][3].

Other names

Activin receptor type IIA (for ACVR2A)Activin receptor type IIB (for ACVR2B)ActRIIAActRIIBACVR2AACVR2BActivin type 2 receptor (generic for both)TGF-beta receptor type IIA/ IIB (less common)

Ligand trap: Antibodies or ligand traps bind to the extracellular domain of ACVR2A/ACVR2B, blocking activin and myostatin binding, inhibiting signal transduction[8][3][2]. Receptor blockade: Preventing phosphorylation and downstream SMAD signaling activation[5][4].