Evidence for the activation of 6-phosphofructo-1-kinase by cAMP-dependent protein kinase in Aspergillus niger.
The change from pentose phosphate pathway to glycolysis plays a significant role in the physiology of Aspergillus niger during the induction of citric acid accumulation. Evidence is shown for the importance of 6-phosphofructo-1-kinase in this process since it is activated by phosphorylation. By incubating a purified active form of the enzyme together with commercially available alkaline phosphatase, 6-phosphofructo-1-kinase activity was lost after a certain time suggesting that the enzyme was dephosphorylated. Inactive 6-phosphofructo-1-kinase could be isolated from the cells in the early stage of growth in a high citric acid yielding medium. The enzyme was "in vitro" activated by isolated protein kinase in the presence of cAMP, ATP and Mg2+ ions. Additional evidence for covalent phosphorylation of inactive 6-phosphofructo-1-kinase was obtained by incubating both enzymes together with labelled [gamma-32P]ATP. The activating enzyme was partially purified from A. niger mycelium.
National Institute of Chemistry, Ljubljana, Slovenia.
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D000469:Alkaline Phosphatase / Q000378:metabolism; D001234:Aspergillus niger / Q000201:enzymology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D010732:Phosphofructokinase-1 / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation
D010732:Phosphofructokinase-1; D017868:Cyclic AMP-Dependent Protein Kinases; D000469:Alkaline Phosphatase