Stimulation of FA and casein kinase II by insulin in 3T3-L1 cells.
Insulin stimulates protein phosphatase-1 and FA, assayed as phosphatase-1 activator, in 3T3-L1 cells. Since other kinases, such as casein kinase-II may also contribute to such FA activity, we assayed casein kinase-II and FA as peptide kinase on extracts from 3T3-L1 cells that had been exposed to insulin for various times. Under such conditions FA, assayed as phosphatase-1 activator, was stimulated 2-3-fold within 1-2 min. Casein kinase-II was stimulated about 2-fold but at a slightly later time (2-3 min) than FA, making it unlikely that casein kinase-II contributes to FA stimulation. Insulin slightly stimulated also the kinase activity of FA towards a synthetic peptide at 2 min, thus confirming the FA activation seen when FA was assayed as activator of phosphatase-1.
Villa-Moruzzi
E
E
Dipartimento di Biomedicina Sperimentale, Universita' di Pisa, Italy.
Crabb
J W
JW
D000595:Amino Acid Sequence; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D047388:Casein Kinases; D002460:Cell Line; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D054645:Protein Phosphatase 1; D013379:Substrate Specificity
D007328:Insulin; D010455:Peptides; D011494:Protein Kinases; D047388:Casein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1