A NOVEL PUTATIVE G-PROTEIN-COUPLED RECEPTOR HIGHLY EXPRESSED IN LUNG AND TESTIS

A putative novel G protein-coupled receptor was isolated using the pol ymerase chain reaction (PCR) and conventional library screening. Degen erate primers corresponding to the thyroid and the sixth transmembrane regions that are conserved among the G protein-coupled receptors were used to amplify selectively gene fragments of new members of this rec eptor family from a neuroblastoma-glioma cell line cDNA. One of the PC R amplification products that by sequence analysis appeared to contain a partial fragment of a novel G protein-coupled receptor gene was use d as a probe to screen a rat forebrain cDNA library to isolate a full- length clone. Sequence comparison indicates that the new gene belongs to the G protein-coupled receptor family and displays the highest stru ctural similarity with the dog RDC1 orphan receptor and several hormon e peptide receptors. The mRNA for this putative receptor is not expres sed in any specific region of the brain but seems to be localized in a restricted number of peripheral tissues, including lung, testes, and kidney. We suggest that the 4-24 cDNA clone encodes for a novel G prot ein-coupled receptor that may belong to hormone peptide receptor famil y.