New thoughts on the role of the beta-gamma subunit in G-protein signal transduction.
Heterotrimeric G proteins are involved in numerous biological processes, where they mediate signal transduction from agonist-bound G-protein-coupled receptors to a variety of intracellular effector molecules and ion channels. G proteins consist of two signaling moieties: a GTP-bound alpha subunit and a beta-gamma heterodimer. The beta-gamma dimer, recently credited as a significant modulator of G-protein-mediated cellular responses, is postulated to be a major determinant of signaling fidelity between G-protein-coupled receptors and downstream effectors. In this review we have focused on the role of beta-gamma signaling and have included examples to demonstrate the heterogeneity in the heterodimer composition and its implications in signaling fidelity. We also present an overview of some of the effectors regulated by beta-gamma and draw attention to the fact that, although G proteins and their associated receptors play an instrumental role in development, there is rather limited information on beta-gamma signaling in embryogenesis.
Vanderbeld
B
B
Department of Zoology, University of Western Ontario, London, Canada.
Kelly
G M
GM
D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D002460:Cell Line; D019281:Dimerization; D051157:Frizzled Receptors; D006160:Guanosine Triphosphate / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D007448:Invertebrates / Q000196:embryology; D017136:Ion Transport / Q000502:physiology; D046911:Macromolecular Substances; D008954:Models, Biological; D015221:Potassium Channels / Q000502:physiology; D021122:Protein Subunits; D011506:Proteins / Q000235:genetics / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D011956:Receptors, Cell Surface / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013329:Structure-Activity Relationship; D014714:Vertebrates / Q000196:embryology / Q000378:metabolism; D051153:Wnt Proteins; D015027:Zebrafish / Q000196:embryology; D029961:Zebrafish Proteins
D015220:Calcium Channels; D051157:Frizzled Receptors; D046911:Macromolecular Substances; D015221:Potassium Channels; D021122:Protein Subunits; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011943:Receptors, Adrenergic, beta; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C094522:wnt8b protein, zebrafish; D006160:Guanosine Triphosphate; D020962:Heterotrimeric GTP-Binding Proteins