Diversity among the beta subunits of heterotrimeric GTP-binding proteins: characterization of a novel beta-subunit cDNA.
Heterotrimeric guanine nucleotide binding proteins transduce signals from cell surface receptors to intracellular effectors. The alpha subunit is believed to confer receptor and effector specificity on the G protein. This role is reflected in the diversity of genes that encode these subunits. The beta and gamma subunits are thought to have a more passive role in G protein function; biochemical data suggests that beta-gamma dimers are shared among the alpha subunits. However, there is growing evidence for active participation of beta-gamma dimers in some G protein mediated signaling systems. To further investigate this role, we examined the diversity of the beta subunit family in mouse. Using the polymerase chain reaction, we uncovered a new member of this family, G beta 4, which is expressed at widely varying levels in a variety of tissues. The predicted amino acid sequence of G beta 4 is 79% to 89% identical to the three previously known beta subunits. The diversity of beta gene products may be an important corollary to the functional diversity of G proteins.
von Weizsäcker
E
E
Institut für Entwicklungsbiologie, Universität Köln, FRG.
Strathmann
M P
MP
Simon
M I
MI
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D019204:GTP-Binding Proteins / Q000235:genetics*; D014644:Genetic Variation; D051379:Mice; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000235:genetics*; D014018:Tissue Distribution
D019204:GTP-Binding Proteins