Activin receptor type IIA and Activin receptor type IIB (ACVR2A (for Activin receptor type IIA), ACVR2B (for Activin receptor type IIB))

Activin receptor type IIA (ACVR2A) and activin receptor type IIB (ACVR2B) are transmembrane serine/threonine kinase receptors of the TGF-β receptor superfamily. They serve as key signal transducers for ligands such as activin, myostatin, and GDF11, modulating critical biological processes including muscle mass regulation, cell growth, differentiation, apoptosis, inflammation, and reproduction. Upon ligand binding, these receptors recruit type I receptors, leading to phosphorylation of SMAD proteins that regulate transcription. ACVR2A/B are validated drug targets for muscle-wasting diseases, anemia via erythropoiesis stimulation, and have known roles in certain cancers. Molecular interventions include antagonist antibodies, ligand traps, and small molecules. Safety profiles must consider wide-ranging physiological roles, especially regarding growth and homeostasis.

Other names

ACVR2A (Activin receptor type-2A)ActRIIAACVR2B (Activin receptor type-2B)ActRIIBActivin type II receptorsActivin type 2 receptors

Drugs and biologics that inhibit ligand binding (e.g., myostatin, activin A, GDF11) act as antagonists, preventing downstream SMAD phosphorylation and subsequent gene transcription involved in muscle growth suppression and other functions Ligand traps bind to circulating ligands, preventing activation of ACVR2A/ACVR2B