ISOLATION AND CHROMOSOMAL LOCALIZATION OF A NOVEL HUMAN G-PROTEIN-COUPLED RECEPTOR (GPR3) EXPRESSED PREDOMINANTLY IN THE CENTRAL-NERVOUS-SYSTEM

Degenerate oligonucleotide primers designed against known G-protein-co upled receptors were used in polymerase chain reaction amplification t o isolate a novel receptor sequence (R4) from a rat insulinoma cell li ne and its human homolog (GPR3) from a human neuroblastoma cDNA librar y, The novel human receptor sequence is expressed in low abundance pre dominantly in the central nervous system and at low levels in the lung and kidney. The gene encoding GPR3 is intronless within the coding re gion, contains at least one intron in the 5'-untranslated region, and has been localized to chromosome 1p34.3. The activating ligand for the homologous receptors R4 and GPR3 is not known, but sequence similarit y with the closely related orphan rat receptor R334 [FEES Lett. 292:24 3 (1991)] suggests that R334 and the homologous receptors R4 and GPR3 probably represent two discrete molecular subtypes that interact with the same or closely related ligands. (C) 1994 Academic Press, Inc.