International Union of Basic and Clinical Pharmacology: Chemerin Receptors CMKLR1 (ChemerinWell1) and GPR1 (Chemerin2) Nomenclature, Pharmacology and Function23 May 2018
Chemerin, a chemoattractant protein and adipokine, has been identified as the endogenous ligand for a G protein-coupled receptor encoded by the gene CMKLR1 (also known as ChemR23) and as a consequence the receptor protein was renamed the chemerin receptor in 2013. Since then, chemerin has been identified as the endogenous ligand for a second G protein-coupled receptor, encoded by the gene GPR1. Therefore, the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification recommends that the official name of the receptor protein for CMKLR1 is chemerin receptor 1 and GPR1 is chemerin receptor 2 to follow the convention of naming the receptor protein after the endogenous ligand. Chemerin receptor 1 and chemerin receptor 2 can be abbreviated to Chemerin1 and Chemerin2 respectively. Chemerin requires C-terminal processing for activity and human chemerin21-157 is reported to be the most active form, with peptide fragments derived from the C-terminus biologically active at both receptors. Small molecule antagonist, CCX832, selectively blocks CMKLR1, and resolvin E1 activation of CMKLR1 is discussed. Activation of both receptors by chemerin is via coupling to Gi/o causing inhibition of adenylyl cyclase and increased Ca2+ flux. Receptors and ligand are widely expressed in human, rat and mouse, and both receptors share ~80% identity across these species. CMKLR1 knock-out mice highlight the role of this receptor in inflammation and obesity and similarly GPR1 knock-out mice exhibit glucose intolerance. In addition, the chemerin receptors have been implicated in cardiovascular disease, cancer, steroidogenesis, HIV replication and neurogenerative disease.