ACTRIIB Extracellular Domain (human, recombinant)

Activin receptor type IIB (ACTRIIB) is a type II activin receptor and member of the TGF-beta receptor superfamily. It is composed of an extracellular ligand-binding domain, a transmembrane domain, an intracellular kinase domain, and a C-terminal tail. ACTRIIB is ubiquitously expressed in fetal development with the highest expression in the brain and spinal cord and is enriched in adult skeletal muscle. ACTRIIB has several ligands, including activins, growth differentiation factor 8 (GDF8), also known as myostatin, and bone morphogenetic proteins (BMPs). Upon ligand binding, ACTRIIB forms a complex with type I activin receptors, which results in their activation and signaling via the SMAD pathway. ACTRIIB is involved in hematopoiesis, myogenesis, and bone formation and resorption. Mutations in the gene encoding ACTRIIB, ACVR2B, are associated with left-right axis malformations. Formulations containing a fusion protein of the ACTRIIB ligand-binding domain with the Fc of an immunoglobulin have been used as erythroid maturation agents in the treatment of anemia in patients with beta-thalassemia or myelodysplastic syndrome (MDS). Cayman's ACTRIIB Extracellular Domain (human, recombinant) protein can be used for binding assay and cell-based assay applications. This protein consists of 127 amino acids, has a calculated molecular weight of 15 kDa, and a predicted N-terminus of Ser19 after signal peptide cleavage. By SDS-PAGE, under reducing conditions, the apparent molecular mass of the protein is 33-38 kDa due to glycosylation.