Oxoeicosanoid receptor 1 (OXER1) also known as G-protein coupled receptor 170 (GPR170) is a protein that in humans is encoded by the OXER1 gene located on human chromosome 2p21; it is the principal receptor for the 5-Hydroxyicosatetraenoic acid family of carboxy fatty acid metabolites derived from arachidonic acid.[3][4][5] The receptor has also been termed hGPCR48, HGPCR48, and R527 but OXER1 is now its preferred designation.[6][7][8][9][10][4][11] OXER1 is a G protein-coupled receptor (GPCR) that is structurally related to the hydroxy-carboxylic acid (HCA) family of G protein-coupled receptors whose three members are HCA1 (GPR81), HCA2 (Niacin receptor 1), and HCA3 (Niacin receptor 2); OXER1 has 30.3%, 30.7%, and 30.7% amino acid sequence identity with these GPCRs, respectively.[12] It is also related (30.4% amino acid sequence identity) to the recently defined receptor, GPR31, for the hydroxyl-carboxy fatty acid 12-HETE.[12][13]
^Koike D, Obinata H, Yamamoto A, Takeda S, Komori H, Nara F, Izumi T, Haga T (2006). "5-Oxo-eicosatetraenoic acid-induced chemotaxis: identification of a responsible receptor hGPCR48 and negative regulation by G protein G(12/13)". J. Biochem. 139 (3): 543–549. doi:10.1093/jb/mvj060. PMID16567419.