Ghrelin Receptor Antibodies
The ghrelin (GHSR) receptor is activated by a 28 amino-acid peptide originally isolated from rat stomach. A unique post-translational modification octanoylation of Ser3 is essential for full activity in binding to ghrelin receptors in the hypothalamus and pituitary, and for the release of growth hormone from the pituitary. Ghrelin stimulates gastric acid secretion and motility. Central and peripheral administration of ghrelin to animals increases food intake leading to weight gain and reduced fat utilization suggesting that the peptide (with several other peptides) may have significant effects on appetite and energy. An endogenous antagonist called Liver enriched antimicrobial peptide 2 (Leap2), expressed primarily in hepatocytes and in enterocytes of the proximal intestine inhibits ghrelin receptor-induced GH secretion and food intake. The secretion of Leap2 and ghrelin is inversely regulated under various metabolic conditions. In cell systems, the ghrelin receptor is constitutively active. The ghrelin receptor stimulates Gq- and Gα12/13-coupled signaling. Ghrelin receptors are regulated by phosphorylation of carboxyl-terminal serine362/serine363 (pS362/pS363-GHSR). This nomenclature refers to the human Ghrelin receptor. This phosphorylation motif is conserved across species but corresponds to pS360/pS361-GHSR in mice and rats. For more information on ghrelin receptor pharmacology please refer to the IUPHAR database. For further reading refer to:
Davenport AP, Bonner TI, Foord SM, Harmar AJ, Neubig RR, Pin JP, Spedding M, Kojima M, Kangawa K. International Union of Pharmacology. LVI. Ghrelin receptor nomenclature, distribution, and function. Pharmacol Rev. 2005 Dec;57(4):541-6. doi: 10.1124/pr.57.4.1. PMID: 16382107.
Ge X, Yang H, Bednarek MA, Galon-Tilleman H, Chen P, Chen M, Lichtman JS, Wang Y, Dalmas O, Yin Y, Tian H, Jermutus L, Grimsby J, Rondinone CM, Konkar A, Kaplan DD. LEAP2 Is an Endogenous Antagonist of the Ghrelin Receptor. Cell Metab. 2018 Feb 6;27(2):461-469.e6. doi: 10.1016 j.cmet.2017.10.016. PMID: 29233536.