Regulation of adenylate cyclase by hormones and G-proteins.
Over the past few years, it has become apparent that a large number of transmembrane signaling systems operate through heterotrimeric G-proteins [( 1] Gilman, A.G. (1984) Cell 36, 577-579; [2] Baker, P.F. (1986) Nature 320, 395). Adenylate cyclase is regulated by stimulatory hormones through Gs(alpha s beta gamma) and inhibitory hormones through Gi(alpha i beta gamma) [( 2]; Katada, T. et al. (1984) J. Biol. Chem. 259, 3586-3595), whereas the breakdown of phosphatidylinositol bisphosphate (PIP2) to inositol trisphosphate (IP3) and diacylglycerol (DG) by phospholipase C is probably also mediated by a heterotrimeric G-protein (Go or Gi) [1,2]. Similarly, the activation of cGMP phosphodiesterase by light-activated rhodopsin is mediated through the heterotrimeric G-protein transducin (Stryer, L. (1986) Rev. Neurosci. 9, 89-119). Other transmembrane signaling systems may also be found to involve G-proteins similar to those already recognized. Because of the emerging universality of G-proteins as transducers of receptor-triggered signals, it may be useful to evaluate the current models prevailing in the adenylate cyclase field, as these models seem to guide our way in evaluating the role of G-proteins in transmembrane signaling, in general.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D004075:Diglycerides / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D006728:Hormones / Q000502:physiology*; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism; D008956:Models, Chemical; D010716:Phosphatidylinositols / Q000378:metabolism
D004075:Diglycerides; D006728:Hormones; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D015544:Inositol 1,4,5-Trisphosphate; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases