Inhibin, beta A, also known as INHBA, is a protein which in humans is encoded by the INHBAgene.[5] INHBA is a subunit of both activin and inhibin, two closely related glycoproteins with opposing biological effects.
Function
The inhibin beta A subunit joins the alpha subunit to form a pituitary FSH secretion inhibitor. Inhibin has been shown to regulate gonadal stromal cell proliferation negatively and to have tumor-suppressor activity. In addition, serum levels of inhibin have been shown to reflect the size of granulosa-cell tumors and can therefore be used as a marker for primary as well as recurrent disease. Because expression in gonadal and various extragonadal tissues may vary several fold in a tissue-specific fashion, it is proposed that inhibin may be both a growth/differentiation factor and a hormone. Furthermore, the beta A subunit forms a homodimer, activin A, and also joins with a beta B subunit to form a heterodimer, activin AB, both of which stimulate FSH secretion. Finally, it has been shown that the beta A subunit mRNA is identical to the erythroid differentiation factor subunit mRNA and that only one gene for this mRNA exists in the human genome.[6]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Burger HG, Igarashi M (April 1988). "Inhibin: definition and nomenclature, including related substances". Endocrinology. 122 (4): 1701–2. doi:10.1210/endo-122-4-1701. PMID3345731.
Welt C, Sidis Y, Keutmann H, Schneyer A (2002). "Activins, inhibins, and follistatins: from endocrinology to signaling. A paradigm for the new millennium". Exp. Biol. Med. (Maywood). 227 (9): 724–52. doi:10.1177/153537020222700905. PMID12324653. S2CID19795772.
Tanimoto K, Handa S, Ueno N, et al. (1992). "Structure and sequence analysis of the human activin beta A subunit gene". DNA Seq. 2 (2): 103–10. doi:10.3109/10425179109039678. PMID1777673.
Burger HG, Igarashi M (1988). "Inhibin: definition and nomenclature, including related substances". Endocrinology. 122 (4): 1701–2. doi:10.1210/endo-122-4-1701. PMID3345731.
Mason AJ, Niall HD, Seeburg PH (1986). "Structure of two human ovarian inhibins". Biochem. Biophys. Res. Commun. 135 (3): 957–64. doi:10.1016/0006-291X(86)91021-1. PMID3754442.
Sumitomo S, Inouye S, Liu XJ, et al. (1995). "The heparin binding site of follistatin is involved in its interaction with activin". Biochem. Biophys. Res. Commun. 208 (1): 1–9. doi:10.1006/bbrc.1995.1297. PMID7887917.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID8125298.
Nishihara T, Okahashi N, Ueda N (1994). "Activin A induces apoptotic cell death". Biochem. Biophys. Res. Commun. 197 (2): 985–91. doi:10.1006/bbrc.1993.2576. PMID8267637.
ten Dijke P, Ichijo H, Franzén P, et al. (1993). "Activin receptor-like kinases: a novel subclass of cell-surface receptors with predicted serine/threonine kinase activity". Oncogene. 8 (10): 2879–87. PMID8397373.