GIV is a nonreceptor GEF for G alpha i with a unique motif that regulates Akt signaling.

ABSTRACT: Heterotrimeric G proteins are molecular switches that control signal transduction. Ligand-occupied, G protein-coupled receptors serve as the canonical guanine nucleotide exchange factors (GEFs) that activate heterotrimeric G proteins. A few unrelated nonreceptor GEFs have also been described, but little or nothing is known about their structure, mechanism of action, or cellular functions in mammals. We have discovered that GIV/Girdin serves as a nonreceptor GEF for G alpha i through an evolutionarily conserved motif that shares sequence homology with the synthetic GEF peptide KB-752. Using the available structure of the KB-752 x G alpha i1 complex as a template, we modeled the G alpha i-GIV interface and identified the key residues that are required to form it. Mutation of these key residu

SUBMITTER: Garcia-Marcos M 

PROVIDER: S-EPMC2651282 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature