Open AccessEvidence for the activation of 6‐phosphofructo‐1‐kinase by cAMP‐dependent protein kinase in Aspergillus niger
Author(s) -
Legiša Matic,
Benčina Mojca
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb06848.x
Subject(s) - biochemistry , enzyme , aspergillus niger , kinase , protein kinase a , glycolysis , citric acid , phosphorylation , biology , chemistry
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‐phophofructo‐1‐kinase in this process since it is activated by phosphorylation. By incubating a purified active form of 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 Mg 2+ ions. Additional evidence for covalent phosphorylation of inactive 6‐phosphofructo‐1‐kinase was obtained by incubating both enzymes together with labelled [ γ − 32 P]ATP. The activating enzyme was partially purified from A. niger mycelium.