Substrate specificity of the phosphorylated fructose-1,6-bisphosphatase dephosphorylating protein phosphatase from Saccharomyces cerevisiae.
Enzymatic dephosphorylation of the phosphorylated forms of five different yeast enzymes has been studied: fructose-1,6-bisphosphatase, glycogen phosphorylase, neutral trehalase, NAD-glutamate dehydrogenase and 6-phosphofructo-2-kinase. Phosphorylated fructose-1,6-bisphosphatase and phosphorylated 6-phosphofructo-2-kinase were present in extracts of starved yeast cells which had been incubated for 10 min with glucose. Phosphorylated glycogen phosphorylase, neutral trehalase and NAD-glutamate dehydrogenase were obtained by incubation of yeast extract with ATP, cyclic AMP and Mg2+. After incubation with commercially available preparations of alkaline phosphatase, all five phosphorylated enzymes studied showed the changes in catalytic activity that would be expected as a consequence of dephosphorylation. The recently purified yeast enzyme which dephosphorylates phosphorylated fructose-1,6-bisophosphatase (Horn and Holzer (1987) however, was found to be active only with the phosphorylated fructose-1,6-bisphosphatase, but not with the other four phosphorylated enzymes studied. By contrast, a crude extract from yeast showed dephosphorylating activity towards all five substrates. Substrate specificity with the five phosphorylated enzymes studied of different phosphoprotein phosphatases from yeast prepared by others is discussed.
Manhart
A
A
Biochemisches Institut, Universität Freiburg, West Germany.
Holzer
H
H
D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D025481:Phosphofructokinase-2; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D006005:Phosphorylases / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity; D014198:Trehalase / Q000378:metabolism
D005969:Glutamate Dehydrogenase; D006005:Phosphorylases; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; D006597:Fructose-Bisphosphatase; D010749:Phosphoprotein Phosphatases; D014198:Trehalase