A multisubstrate Ca2+ and cyclic nucleotide independent kinase from vascular smooth muscle: modulation of activity by polycations.
A multisubstrate Ca2+ and cyclic nucleotide independent kinase (Mr = 47,000) was purified from bovine aortic smooth muscle. Phosphorylation of glycogen synthase by this enzyme was polycation modulable. Low concentrations of polylysine (0.04-0.16 microM) stimulated phosphorylation 2-7 fold, whereas higher concentrations suppressed phosphorylation. Glycogen synthase converted to its glucose 6-PO4 dependent form following phosphorylation in either the presence (7 mol 32P/mol synthase) or absence (4 mol 32P/mol synthase) of polylysine: extent of conversion correlated to extent of phosphorylation. Seven of 14 potential substrates tested were phosphorylated: kinase activity was greatest for phosvitin followed by casein, the receptor protein from type 2 cAMP-kinase, histone H2b, phosphorylase kinase, glycogen synthase, and myocardial myosin light chains. Phosphorylation of phosvitin or synthase was inhibited by heparin (1/2 maximally by 0.5 microgram/ml without salt and 37 micrograms/ml with 150 mM NaCl). The results suggest that the enzyme may participate in regulating arterial glycogen metabolism and that such regulation may be modulated by polycationic and polyanionic effectors.
D000818:Animals; D001011:Aorta / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology; D002364:Caseins / Q000378:metabolism; D002412:Cations; D002417:Cattle; D000242:Cyclic AMP / Q000494:pharmacology; D006006:Glycogen Synthase / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D010766:Phosphorylation; D010774:Phosvitin / Q000378:metabolism; D011073:Polyamines; D000071228:Polyelectrolytes; D011107:Polylysine / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D013379:Substrate Specificity
D002118:Calcium; D002364:Caseins; D002412:Cations; D000242:Cyclic AMP; D006006:Glycogen Synthase; D006493:Heparin; D010774:Phosvitin; D011073:Polyamines; D000071228:Polyelectrolytes; D011107:Polylysine; D011108:Polymers; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases