title: Adenosine 3':5'-cyclic monophosphate control of the enzymes of glutamine metabolism in Escherichia coli.
abstract: The effect of cAMP on the intracellular levels of five enzymes concerned with the interconversion of glutamate and glutamine in E. 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.
mesh_terms: D000262:Adenylyl Cyclases / Q000494:pharmacology; D001426:Bacterial Proteins / Q000494:pharmacology; D002247:Carbon Isotopes; D002701:Chloramphenicol / Q000494:pharmacology; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005972:Glutaminase / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism*; D007656:Ketoglutaric Acids; D009154:Mutation; D009994:Osmolar Concentration; D011955:Receptors, Drug / Q000187:drug effects; D013329:Structure-Activity Relationship; D000637:Transaminases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D007656:Ketoglutaric Acids; D011955:Receptors, Drug; D005973:Glutamine; D002701:Chloramphenicol; D000242:Cyclic AMP; D005969:Glutamate Dehydrogenase; D000637:Transaminases; D005972:Glutaminase; D000262:Adenylyl Cyclases; D005974:Glutamate-Ammonia Ligase