title: RpoS proteolysis is controlled directly by ATP levels in Escherichia coli.
abstract: 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.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Celeste N
authors.initials: CN
authors.lastname: Peterson
authors.forename: Igor
authors.initials: I
authors.lastname: Levchenko
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Rabinowitz
authors.forename: Tania A
authors.initials: TA
authors.lastname: Baker
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Silhavy
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D055550:Protein Stability; D059748:Proteolysis; D012808:Sigma Factor / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D009243:NAD; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate