Open AccessAdenosine 3′:5′-Cyclic Monophosphate Control of the Enzymes of Glutamine Metabolism in Escherichia coli
Author(s) -
Stanley B. Prusiner,
R Eric Miller,
Raymond C. Valentine
Publication year - 1972
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.69.10.2922
Subject(s) - glutaminase , glutamate dehydrogenase , glutamine synthetase , glutamine , enzyme , biochemistry , glutamate synthase , glutamine amidotransferase , metabolism , biology , glutamate receptor , chloramphenicol , receptor , amino acid , antibiotics
The effect of cAMP on the intracellular levels of five enzymes concerned with the interconversion of glutamate and glutamine inE. coli has been examined. Cyclic AMP added to the culture medium increases the levels of glutamate dehydrogenase (EC 1.4.1.4) and glutamine synthetase (EC 6.3.1.2); it decreases the levels of glutamate synthase (EC 1.4.1.X), and glutaminase A (EC 3.5.1.2). Cyclic AMP did not affect the level of glutaminase B (EC 3.5.1.2). These alterations in enzyme levels by cAMP require cyclic AMP receptor protein, since the levels of these enzymes were unchanged by cAMP in a mutant lacking this receptor. Chloramphenicol also abolished the effects of cAMP, a result that implies protein synthesis is necessary for these changes in enzyme levels to occur. The reciprocal effects of cAMP on the levels of these enzymes may play an important role in the cellular regulation of nitrogen metabolism.