Gonadotropin-releasing hormone receptor 1 (GnRHR)

Gonadotropin-releasing hormone receptor 1 is a class A (rhodopsin-like) G protein-coupled receptor (GPCR) encoded by the GNRHR gene. It is predominantly expressed on pituitary gonadotrope cells but also appears in tissues such as the breast, ovary, prostate, and some cancers[4][7][8]. Upon binding to its ligand, gonadotropin-releasing hormone (GnRH), this receptor activates G proteins that stimulate the phosphatidylinositol-calcium second messenger system, leading to the synthesis and release of the gonadotropins LH and FSH, which are essential for reproductive function in both males and females[2][4][7]. The GnRHR lacks the typical C-terminal tail found in most GPCRs, which gives it unique regulatory properties[1][3]. Gonadotropin-releasing hormone receptor 1 is a critical therapeutic target in endocrinology and oncology for conditions such as hormone-responsive cancers, endometriosis, and infertility[5][6]. Both agonists and antagonists of this receptor are used clinically: agonists initially stimulate but then downregulate the receptor (suppressing gonadotropin and sex steroid levels), while antagonists provide immediate blockade of gonadotropin secretion[6][7]. Mutations in GNRHR can cause congenital hypogonadotropic hypogonadism[1][4], and extrapituitary expression is implicated in some cancer growth and progression[7]. Structural studies have elucidated its binding modes and activation mechanisms, facilitating targeted drug design[3][5].

Other names

GnRHRGnRH1RLuteinizing hormone-releasing hormone receptor (LHRHR)GNRHR (gene name)Gonadorelin receptorLuliberin receptor

Agonist stimulation leads to desensitization and downregulation of gonadotropin release, thereby suppressing sex hormone production Antagonists block receptor activation, acutely inhibiting gonadotropin secretion Both classes affect synthesis and release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)