Activin receptor type-2B (ACVR2B) (ACVR2B)

Activin receptor type-2B (ACVR2B) is a high-affinity transmembrane serine/threonine kinase receptor that serves as a critical node for several ligands in the Transforming Growth Factor-beta (TGF-beta) superfamily, including Myostatin, Activin A, and GDF11 [1]. Upon ligand binding, ACVR2B forms a heteromeric complex with type I receptors, triggering intracellular signaling through Smad2 and Smad3 to regulate diverse physiological processes such as muscle growth, bone density, and red blood cell production [1,2]. In pathological states like cancer cachexia, sarcopenia, or certain anemias, overactivation of this pathway leads to debilitating muscle wasting or impaired erythropoiesis [3]. Therapeutic strategies targeting this system frequently utilize the extracellular domain (ECD) of ActRIIB as a soluble decoy or "ligand trap" (e.g., Luspatercept) to sequester circulating ligands, or employ monoclonal antibodies (e.g., Bimagrumab) to block the receptor directly [3,4]. These interventions aim to restore muscle function, increase bone mass, or treat chronic anemia by modulating the signaling balance within the TGF-beta superfamily [2,3].

Other names

ActRIIBActivin receptor type IIBACVR2BActR-IIB

Ligand sequestration (trapping) of TGF-beta superfamily members (e.g., Myostatin, Activin A, GDF11) using soluble receptor decoys, or competitive antagonism of the membrane-bound receptor using monoclonal antibodies [1,3].