The demonstration in rat liver cell sap of protein kinase and phosphoprotein phosphatase active on fructose-bisphosphatase.
A protein kinase active on fructose-bisphosphatase (D-fructose-1,6-bisphosphate 1-phosphohydrolase, EC 3.1.3.11) was demonstrated in rat liver cell sap. The protein kinase activity was stimulated by cyclic AMP and coincided with the activity of cyclic AMP-dependent protein kinase type I. In addition, three different peaks of phosphoprotein phosphatase active on [32P] phosphofructose-bisphosphatase were found on chromatography of rat liver cell sap on a DEAE-cellulose column. These phosphatases needed divalent cations for full activity. 5'-AMP, a negative modulator of fructose-bisphosphatase, had no effect on the phosphorylation-de-phosphorylation reactions of the enzyme. ATP and Ca2+ did not influence the dephosphorylation reaction of fructose-bisphosphatase.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D013552:Swine
D000242:Cyclic AMP; D011494:Protein Kinases; D006597:Fructose-Bisphosphatase; D010749:Phosphoprotein Phosphatases; D002118:Calcium