title: Does subunit dissociation necessarily accompany the activation of all heterotrimeric G proteins?
abstract: Heterotrimeric (alpha beta gamma) G proteins mediate a variety of signal transduction events in virtually every cell of every eukaryotic organism. The predominant hypothesis is that dissociation of the alpha-subunit from the G beta gamma-subunit complex necessarily accompanies the activation of these proteins, and that the alpha-subunit is primarily responsible for regulating the response of effector molecules. However, there is increasing evidence that both the alpha-subunit and the beta gamma-subunit complex function in regulating effector activity. Furthermore, data for some G proteins suggest that they function as activated heterotrimers rather than as dissociated subunits.
authors.affiliation: Membrane Biochemistry Section, NINDS, NIH, Bethesda, MD 20892, USA.
authors.forename: R V
authors.initials: RV
authors.lastname: Rebois
authors.forename: D R
authors.initials: DR
authors.lastname: Warner
authors.forename: N S
authors.initials: NS
authors.lastname: Basi
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000737:chemistry*; D011487:Protein Conformation; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D019204:GTP-Binding Proteins