Evolution of the mammalian G protein α subunit multigene family

Heterotrimeric guanine nucleotide binding proteins (G proteins) transduce extracellular signals received by transmembrane receptors to effector proteins. The multigene family of G protein α subunits, which interact with receptors and effectors, exhibit a high level of sequence diversity. In mammals, 15 Gα subunit genes can be grouped by sequence and functional similarities into four classes. We have determined the murine chromosomal locations of all 15 Gα subunit genes using an interspecific backcross derived from crosses of C57BI/6J and Mus spretus mice. These data, in combination with mapping studies in humans, have provided insight into the events responsible for generating the genetic diversity found in the mammalian α subunit genes and a framework for elucidating the role of the Gα subunits in disease.