TitleRpoS proteolysis is controlled directly by ATP levels in Escherichia coli.
Publication TypeJournal Article
Year of Publication2012
AuthorsPeterson, CN, Levchenko, I, Rabinowitz, JD, Baker, TA, Silhavy, TJ
JournalGenes Dev
Date Published2012 Mar 15
KeywordsAdenosine Triphosphate, Bacterial Proteins, Escherichia coli, Guanosine Triphosphate, NAD, Protein Stability, Proteolysis, Sigma Factor

The master regulator of stationary phase in Escherichia coli, RpoS, responds to carbon availability through changes in stability, but the individual steps in the pathway are unknown. Here we systematically block key steps of glycolysis and the citric acid cycle and monitor the effect on RpoS degradation in vivo. Nutrient upshifts trigger RpoS degradation independently of protein synthesis by activating metabolic pathways that generate small energy molecules. Using metabolic mutants and inhibitors, we show that ATP, but not GTP or NADH, is necessary for RpoS degradation. In vitro reconstitution assays directly demonstrate that ClpXP fails to degrade RpoS, but not other proteins, at low ATP hydrolysis rates. These data suggest that cellular ATP levels directly control RpoS stability.

Alternate JournalGenes Dev.