Genomic Characterization of the Human Heterotrimeric G Protein α, β, and γ Subunit Genes

Heterotrimeric guanine nucleotide binding proteins (G proteins) transduce extracellular signals received by transmembrane receptors to effector proteins. Each subunit of the G protein complex is encoded by a member of one of three corresponding gene families. Currently, 16 different members of the a subunit family, 5 different members of the (3 subunit family, and 11 different members of the 7 subunit family have been described in mammals. Here we have identified and characterized Bacterial Artificial Chromosomes (BACs) containing the human homologs of each of the a, (3, and 7 subunit genes as well as a Gal l pseudogene and a previously undiscovered G75-like gene. The gene structure and chromosome location of each gene was determined, as were the orientations of paired genes. These results provide greater insight into the evolution and functional diversity of the mammalian G protein subunit genes.