Isolation, tissue expression, and chromosomal assignment of human RGS5, a novel G-protein signaling regulator gene.

The regulator of G-protein signaling (RGS) proteins have recently been identified as signal transduction molecules which have structural homology to SST2 of Saccharomyces cerevisiae and EGL-10 of Caenorhabditis elegans. Multiple genes homologous to SST2 are present in higher eukaryotes, and the group of these genes is termed the RGS family. RGS proteins are involved in the regulation of heterotrimeric G-proteins by acting as GTPase-activators. A putative new member of the RGS family was isolated from a neuroblastoma cDNA library. The amino acid sequence deduced from the cDNA possessed all consensus motifs of the RGS domain and showed closest homology to mouse RGS5 (90% identical), indicating that it was human RGS5 (hRGS5). The messenger RNA of hRGS5 was abundantly expressed in heart, lung, skeletal muscle, and small intestine, and at low levels in brain, placenta, liver, colon, and leukocytes. The chromosome localization of the gene in the 1q23 region was determined by a monochromosomal hybrid panel and a radiation hybrid panel.