The paradoxical regulation of protein phosphorylation in insulin action.
Many cellular actions of insulin are mediated by changes in protein phosphorylation. The consequences of these phosphorylation events extend from a series of different short-term metabolic actions to longer-term effects of the hormone on cellular growth and differentiation. Although the insulin receptor itself is a tyrosine kinase that is activated upon hormone binding, the ensuing changes in phosphorylation occur predominantly on serine and threonine residues. Moreover, insulin can simultaneously stimulate the phosphorylation of some proteins and the dephosphorylation of others. These paradoxical effects of insulin suggest that separate signal transduction pathways may emanate from the receptor itself to produce the pleiotropic actions of the hormone.
Saltiel
A R
AR
Department of Signal Transduction, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, MI 48105.
D000818:Animals; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D015290:Second Messenger Systems
D017261:Glycosylphosphatidylinositols; D007328:Insulin; D011506:Proteins; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases