Gonadotropin-releasing hormone receptor

Protein
Name= Gonadotropin-releasing hormone receptor
Symbol=GNRHR
AltSymbols=GnRH-R; LRHR;
HGNCid=4421
Chromosome=4
Arm=q
Band=21.2
LocusSupplementaryData=
ECnumber=
OMIM=138850
EntrezGene=2798
RefSeq=NM_000406
UniProt=P30968protein
Name = Gonadotropin-releasing hormone (type 2) receptor 2
caption =


width =
HGNCid = 16341
Symbol = GNRHR2
AltSymbols =
EntrezGene = 114814
OMIM =
RefSeq = NR_002328
UniProt = Q96P88
PDB =
ECnumber =
Chromosome = 1
Arm = q
Band = 12
LocusSupplementaryData =

The gonadotropin-releasing hormone receptor (GNRHR), also known as the luteinizing hormone releasing hormone receptor (LHRHR), 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.

This receptor is a 60 kDa G protein-coupled receptor and resides primarily in the pituitary and is responsible for eliciting the actions of LHRH after its release from the hypothalamus.cite journal | author = Millar RP | title = GnRHs and GnRH receptors | journal = Anim. Reprod. Sci. | volume = 88 | issue = 1-2 | pages = 5–28 | year = 2005 | pmid = 16140177 | doi = 10.1016/j.anireprosci.2005.05.032 | issn = ] Upon activation, the LHRHr stimulates tyrosine phosphatase and elicits the release of LH from the pituitary.

Evidence exists showing the presence of LHRH and its receptor in extrapituitary tissues as well as a role in progression of some cancers.cite journal | author = Harrison GS, Wierman ME, Nett TM, Glode LM | title = Gonadotropin-releasing hormone and its receptor in normal and malignant cells | journal = Endocr. Relat. Cancer | volume = 11 | issue = 4 | pages = 725–48 | year = 2004 | pmid = 15613448 | doi = 10.1677/erc.1.00777 | issn = ]

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).

Gene

There are two major forms of the GNRHR, each encoded by a separate receptor (gene|GNRHR, gene|GNRHR2).cite journal | author = Neill JD, Musgrove LC, Duck LW | title = Newly recognized GnRH receptors: function and relative role | journal = Trends Endocrinol. Metab. | volume = 15 | issue = 8 | pages = 383–92 | year = 2004 | pmid = 15380810 | doi = 10.1016/j.tem.2004.08.005 | issn = ] cite journal | author = Cheng CK, Leung PC | title = Molecular biology of gonadotropin-releasing hormone (GnRH)-I, GnRH-II, and their receptors in humans | journal = Endocr. Rev. | volume = 26 | issue = 2 | pages = 283–306 | year = 2005 | pmid = 15561800 | doi = 10.1210/er.2003-0039 | issn = ]

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".

Regulation

The GNRHR responds to GNRH as well as to synthetic 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.

Clinical implications

Defects in the "GNRHR" are a cause of hypogonadotropic hypogonadism (HH).cite journal | author = Layman LC | title = Hypogonadotropic hypogonadism | journal = Endocrinol. Metab. Clin. North Am. | volume = 36 | issue = 2 | pages = 283–96 | year = 2007 | pmid = 17543719 | doi = 10.1016/j.ecl.2007.03.010 | issn = ]

References

External links

* [http://www.iuphar-db.org/GPCR/ReceptorDisplayForward?receptorID=3035 IUPHAR GPCR Database - GnRH receptor]
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