Growth differentiation factor 11 (GDF11) and Activin B (GDF11/Activin B)

Growth differentiation factor 11 (GDF11) and Activin B are members of the transforming growth factor-beta (TGF-beta) superfamily that signal through the Activin type IIB receptor (ActRIIB) (Source: UniProt O95390, P09529). These ligands, along with related molecules like Myostatin and Activin A, act as negative regulators of various physiological processes, most notably late-stage erythropoiesis (Source: PubMed PMID: 32053299). In hematopoietic tissues, they inhibit the maturation of erythroid precursors, and their overactivity is a primary driver of ineffective erythropoiesis in diseases such as beta-thalassemia and myelodysplastic syndromes (Source: NIH/NCI). Therapeutic agents like Luspatercept are designed as "ligand traps," using a recombinant fusion protein to sequester these ligands and prevent them from activating ActRIIB signaling (Source: FDA Reblozyl Label). This mechanism allows for the resumption of effective red blood cell production and reduces the need for blood transfusions in affected patients. Beyond hematology, these ligands are critical regulators of muscle mass and bone density, making them significant targets for research into muscle wasting disorders and metabolic health (Source: PubMed PMID: 24633322).

Other names

BMP11Bone morphogenetic protein 11Inhibin beta-BINHBBActRIIB ligandsMyostatinGDF8Activin A

Ligand trapping; these drugs (e.g., Luspatercept) are fusion proteins consisting of the extracellular domain of ActRIIB linked to an IgG Fc domain, which sequester GDF11 and Activin B to prevent their inhibitory signaling on erythroid maturation (Source: PubMed PMID: 32053299).