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

A putative novel G protein-coupled receptor was isolated using the polymerase chain reaction (PCR) and conventional library screening. Degenerate 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 receptor family from a neuroblastoma-glioma cell line cDNA. One of the PCR amplification products that by sequence analysis appeared to contain a partial fragment of a novel G protein-coupled receptor gene was used 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 structural similarity with the dog RDC1 orphan receptor and several hormone peptide receptors. The mRNA for this putative receptor is not expressed 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 protein-coupled receptor that may belong to hormone peptide receptor family.