Gonadotropin-releasing hormone receptor

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Gonadotropin-releasing hormone receptor
Identifiers
Symbol	GNRHR GnRH-R; LRHR;
HUGO	4421
Entrez	2798
OMIM	138850
RefSeq	NM_000406
UniProt	P30968
Other data
Locus	Chr. 4 q21.2

Gonadotropin-releasing hormone receptor (GNRHR) is a member of the seven-transmembrane, G-protein coupled receptor (GPCR) family. It is expressed on the surface of pituitary gonadotrope cells as well as lymphocytes, breast, ovary, and prostate.

1 Function
2 Gene
3 Regulation
4 Clinical implications

[edit] Function

Following binding of Gonadotropin releasing hormone (GNRH), GNRHR associates with G-proteins that activate a phosphatidylinositol (PtdIns)-calcium second messenger system. Activation of GNRHR ultimately causes the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH).

[edit] Gene

Alternative splicing of the GNRHR gene, GNRHR, results in multiple transcript variants encoding different isoforms. More than 18 transcription initiation sites in the 5' region and multiple polyA signals in the 3' region have been identified for GNRHR.

[edit] Regulation

The GNRHR responds to GNRH as well as to GNRH agonists. Agonists stimulate the receptor, however prolonged exposure leads to a downregulation effect resulting in hypogonadism, an effect that is often medically utilized. GNRH antagonists block the receptor and inhibit gonadotropin release. GNRHRs are further regulated by the presence of sex hormones, inhibin, and activin.

[edit] Clinical implications

Defects in the GNRHR are a cause of hypogonadotropic hypogonadism (HH).

v • d • e

Transmembrane receptor: G protein-coupled receptors

Adenosine - Adrenergic - Angiotensin - Bradykinin - Calcitonin - Cannabinoid - Chemokine - Cholecystokinin - Corticotropin-releasing hormone - Dopamine - Endothelin - FSH-receptor - GABA B - Galanin - Glucagon - Gonadotropin-releasing hormone - Histamine (H1, H2, H3, H4) - Luteinizing hormone/choriogonadotropin - Melanocortin (MC1R, MC2R) - Melatonin - Metabotropic glutamate - Muscarinic acetylcholine - Neurotensin - Olfactory - Opioid (Delta, Kappa, Mu, Sigma, Nociceptin) - Parathyroid hormone - Purinergics (P2Y) - Trace amine-associated - Secretin - Serotonin, all but 5-HT3 (5-HT2A)

Rhodopsin

v • d • e Sex hormones and related agents (primarily G03, also L02, H01C) - human endogenous in CAPS
Progestogens: (receptor)	PROGESTERONE, Desogestrel, Drospirenone, Dydrogesterone, Ethisterone, Etonogestrel, Ethynodiol diacetate, Gestodene, Gestonorone, Levonorgestrel, Lynestrenol, Medroxyprogesterone, Megestrol, Norelgestromin, Norethisterone, Norethynodrel, Norgestimate, Norgestrel, Norgestrienone, Tibolone Antiprogestogen: Mifepristone
Androgens: (receptor)	TESTOSTERONE, Androstanolone, Fluoxymesterone, Mesterolone, Methyltestosterone, (see also anabolic steroids) Antiandrogens: Bicalutamide, Cyproterone, Flutamide, Nilutamide, Spironolactone
Estrogens: (receptor)	ESTRADIOL, ESTRIOL, ESTRONE, Chlorotrianisene, Dienestrol, Diethylstilbestrol, Ethinylestradiol, Fosfestrol, Mestranol, Polyestradiol phosphate Selective estrogen receptor modulator: Bazedoxifene, Clomifene, Fulvestrant, Raloxifene, Tamoxifen, Toremifene Aromatase inhibitor: Aminogluthetimide, Anastrozole, Exemestane, Formestane, Letrozole, Vorozole
Gonadotropins: (FSHR/LHCGR)	ovulation stim.:Clomifene, Urofollitropin Antigonadotropins: Danazol, Gestrinone
GnRH: (receptor)	agonist: Buserelin, Goserelin, Histrelin, Leuprorelin, Nafarelin, Triptorelin antagonist: Abarelix, Cetrorelix, Ganirelix