Gene structure and expression of g protein subunits

Heteroîrimeric G Proteins, composed of an α, β, and γ subunit, play a central role in cell function by transducing signals from transmembrane receptors to intracellular effectors. Since the nervous system exhibits a wealth of G protein mediated signaling pathways, we have begun characterization of the 7 subunit family bv cloning the genes and examining the expression of those subunits enriched in neural tissue. We have cloned and examined the intronexon structure of the mouse genes for 7l, 72, 73, and 74 and have found that each of these contain a conserved intron which splits the protein coding region centrally. This intron may divide each subunit into functional domains and suggests that these subunits may have evolved from a single ancestral gene. In addition, we have investigated the expression of 72, 73, and 74 via in situ hybridization and have determined that each subunit has a complex distribution pattern in a wide variety of neural structures. Using subunit specific antibodies we have also performed immunohistochemistry to determine the distribution pattern of the 78 protein. We have found that the 7 protein has a wide and complex distribution pattern and is localized in the neuntes but absent from the cell body. We are further investigating the in vivo role of these subunits by disrupting the genes via homologous recombination.