Gene superfamily: inhibins (activins); (INHA INHBA INHBB INHBC)


FUN

 [1] Inhibins and activins are gonadal glycoprotein hormones that selectively control the secretion of the hypophyseal follicle stimulating hormone (FSH) and share a common sunbunit.
[2] Inhibins inhibit FSH secretion and activins are potent stimulators of FSH secretion."

FAG

 [1] Three INH polypeptides (one alpha and two beta peptides, A and B) were mapped. The gene for alpha subunit is assigned to Chr 2 (GEM:02q3/INHA). The gene for beta-A subunit is assigned to Chr 7 (GEM:07p1/INHBA), and that for beta-B subunit is mapped to Chr 2 (GEM:02q1/INHBB). Third beta peptide is mapped to Chr12 (GEM:12q131/INHBC).
[2] Activins are members of a family of polypeptide growth factors that includes also the transforming growth factors-beta (GEM:19q131/TGFB1; GEM:01q41/TGFB2; GEM:14q24/TGFB3), mullerian duct-inhibiting substance (GEM:19p133/AMH), and several bone morphogenetic proteins.
[3] Two types of activin receptors were identified: type I receptor (GEM:02q2/ACVR1; GEM:00.0/ACVRLK4 (ACVR1B)) and type II receptors (GEM:00.0/ACVR2A; GEM:03p2/ACVR2B).
[3] About activin A receptor type II-like kinases see GEM:12q13/ACVRLK1.
[4] The gene coding for beta polypeptide of FSH - follitropin beta - is mapped to chr 11 (GEM:11p13/FSHB)."

MOP

 [1]-Inhibins and activins are homo- or heterodimers consisting of alpha and beta chains covalently linked by one or more disulfide bonds: inhibin A is a dimer of alpha and beta-A chains; inhibin B is a dimer of alpha and beta-B chains; activin A is a homodimer of beta-A chains; activin AB is a dimer of beta-A and beta-B chains; activin B is a homodimer of beta-B chains. The mature peptide, inhibin, has MM 32 kD and consists of one alpha and one beta (A or B) subunits.
[2] On the alpha peptide structure, see GEM:02q3/INHA.
[3] On the beta peptides structure, see GEM:07p1/INHBA."

TIS

 [1] The inhibin expression was found in seminal ducts (in males) and in the ovarian follicle fluid (in females).
[2] Activins impinge on a much broader spectrum of cells than do inhibins; however, in those systems in which both proteins are functional, they have opposing biologic effects."

PHE

 The increased folliculotrophin production in post-menopausal females is supposed to be accounted for by cessation of the ovarian inhibin secretion."

PAT

 A hypothesis has been proposed that the loss of inhibin activity may be one of the reasons for polycystic ovary degeneration (Stein-Leventhal syndrome; MIM:184700; it has not been included in the HUGEN yet)."