Abbreviations used: B. W., body weight; EST, expressed sequence tag; GPCR, G protein-coupled receptor; oGPCR, orphan G protein-coupled receptor; ORF, open reading frame; RACE, rapid amplification of cDNA ends; UTR, untranslated region.
Characterization of Apelin, the Ligand for the APJ Receptor
Article first published online: 25 DEC 2001
Journal of Neurochemistry
Volume 74, Issue 1, pages 34–41, January 2000
How to Cite
Lee, D. K., Cheng, R., Nguyen, T., Fan, T., Kariyawasam, A. P., Liu, Y., Osmond, D. H., George, S. R. and O'Dowd, B. F. (2000), Characterization of Apelin, the Ligand for the APJ Receptor. Journal of Neurochemistry, 74: 34–41. doi: 10.1046/j.1471-4159.2000.0740034.x
- Issue published online: 25 DEC 2001
- Article first published online: 25 DEC 2001
- G protein-coupled receptor;
- CNS expression
Abstract: The apelin peptide was recently discovered and demonstrated to be the endogenous ligand for the G protein-coupled receptor, APJ. A search of the GenBank databases retrieved a rat expressed sequence tag partially encoding the preproapelin sequence. The GenBank search also revealed a human sequence on chromosome Xq25-26.1, containing the gene encoding preproapelin. We have used the rat sequence to screen a rat brain cDNA library to obtain a cDNA encoding the full-length open reading frame of rat preproapelin. This cDNA encoded a protein of 77 amino acids, sharing an identity of 82% with human preproapelin. Northern and in situ hybridization analyses revealed both human and rat apelin and APJ to be expressed in the brain and periphery. Both sequence and mRNA expression distribution analyses revealed similarities between apelin and angiotensin II, suggesting they that share related physiological roles. A synthetic apelin peptide was injected intravenously into male Wistar rats, resulting in immediate lowering of both systolic and diastolic blood pressure, which persisted for several minutes. Intraperitoneal apelin injections induced an increase in drinking behavior within the first 30 min after injection, with a return to baseline within 1 h.