MOLECULAR-CLONING AND CHARACTERIZATION OF A NOVEL ORPHAN RECEPTOR (P-2P) EXPRESSED IN HUMAN PANCREAS THAT SHOWS HIGH STRUCTURAL HOMOLOGY TOTHE P-2U PURINOCEPTOR

Here we report the cloning of a gene encoding a new member of the supe rfamily of G protein-coupled receptors. The gene encodes a protein of 365 amino acids closely resembling two recently cloned nucleotide bind ing receptors, called P-2U and P-2Y purinoceptors (71% and 49% sequenc e identity within the transmembrane domains, respectively). Our studie s show that this new putative purinoceptor (designated P-2P) is encode d by an intronless single copy gene that is exclusively expressed in p ancreas, in contrast to the P-2U and the P-2Y purinoceptors which are widely distributed throughout the periphery. The identification of a p ancreas-specific human putative P-2 purinoceptor makes it attractive t o speculate that the reported actions of ADP/ATP analogues in pancreas on insulin secretion are mediated through this receptor.