RpoS proteolysis is controlled directly by ATP levels in Escherichia coli

• Main Authors: Peterson, Celeste N. (Contributor), Levchenko, Igor (Contributor), Baker, Tania (Contributor), Rabinowitz, Joshua D. (Author), Silhavy, Thomas J. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Biology (Contributor), Massachusetts Institute of Technology. School of Science (Contributor)
• Format: Article
• Language: English
• Published: Cold Spring Harbor Laboratory Press, 2014-03-10T15:21:42Z.
• Subjects: Article
• Online Access: Get fulltext

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.
National Institute of General Medical Sciences (U.S.) (Grant GM049224)