Description
Inhibins are homodimers or heterodimers of the various β subunit isoforms, belonging to the TGFβfamily. Mature Inhibin Beta A has two 116 amino acids residues βA subunits (βA-βA). Inhibin exhibits a wide range of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Inhibin plays a key role in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells known to express Inhibin Beta A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydigcells, Sertolicells, andovarian granulosa cells. As with other members of the super-family, Inhibins interact with two types of cell surface trans-membrane receptors (Types I and II) which have intrinsic serine/threonine kinase activities in their cytoplasmic domains, Inhibin type 1 receptors, ACVR1, ACVR1B, ACVR1C and Inhibin type 2 receptors, ACVR2A, ACVR2B. The biological activity of Inhibin Beta A can be neutralized by inhibins and by the diffusible TGF-B antagonist, Follistatin