title: Polyamine-enhanced casein kinase II in mouse pancreatic islets.
abstract: The occurrence of polyamine-stimulated protein kinase (casein kinase II) in cytosol of mouse pancreatic islets was investigated. Islet protein phosphorylation was enhanced by spermidine, spermine, lysine-rich histone and polylysine; the major endogenous substrates in the cytosol were three proteins of Mr 50,000, 55,000 and 100,000. Cadaverine and putrescine were without effects. A Mr 100,000 protein is a major substrate for Ca2+-calmodulin-dependent protein kinase, and Mr 50,000 and 55,000 proteins are substrates for cyclic adenosine 3',5'-cyclic monophosphate (AMP) dependent protein kinase in mouse islets. However, neither cyclic-AMP-dependent protein kinase inhibitor nor trifluoperazine inhibited polyamine-enhanced protein phosphorylation. Both basal and polyamine-enhanced protein phosphorylation patterns were identical when either [gamma-32P] adenosine 5'-triphosphate (ATP) or [gamma-32P] guanosine 5'-triphosphate (GTP) was used as phosphate donors, indicative of the presence of a polyamine-stimulated casein kinase II in pancreatic islets. It is suggested that polyamines and polyamine-enhanced casein kinase II activity may have an important role in regulation of protein phosphorylation in pancreatic islets.
mesh_terms: D000818:Animals; D002103:Cadaverine / Q000494:pharmacology; D047388:Casein Kinases; D006657:Histones / Q000494:pharmacology; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051379:Mice; D010766:Phosphorylation; D011073:Polyamines / Q000494:pharmacology*; D011107:Polylysine / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D011700:Putrescine / Q000494:pharmacology; D013095:Spermidine / Q000494:pharmacology; D013096:Spermine / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
chemical_list: D006657:Histones; D011073:Polyamines; D047428:Protein Kinase Inhibitors; D014268:Trifluoperazine; D011107:Polylysine; D013096:Spermine; D011494:Protein Kinases; D047388:Casein Kinases; D002103:Cadaverine; D013095:Spermidine; D011700:Putrescine