Inorganic polyphosphate and the induction of rpoS expression.
Inorganic polyphosphate [poly(P)] levels in Escherichia coli were reduced to barely detectable concentrations by expression of the plasmid-borne gene for a potent yeast exopolyphosphatase [poly(P)ase]. As a consequence, resistance to H2O2 was greatly diminished, particularly in katG (catalase HPI) mutants, implying a major role for the other catalase, the stationary-phase KatE (HPII), which is rpoS dependent. Resistance was restored to wild-type levels by complementation with plasmids expressing ppk, the gene for PPK [the polyphosphate kinase that generates poly(P)]. Induction of expression of both katE and rpoS (the stationary-phase sigma factor) was prevented in cells in which the poly(P)ase was overproduced. Inasmuch as this inhibition by poly(P)ase did not affect the levels of the stringent-response guanosine nucleotides (pppGpp and ppGpp) and in view of the capacity of additional rpoS expression to suppress the poly(P)ase inhibition of katE expression, a role is proposed for poly(P) in inducing the expression of rpoS.
Shiba
T
T
Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060, Japan. shiba@moby.hokudai.ac.jp
Tsutsumi
K
K
Yano
H
H
Ihara
Y
Y
Kameda
A
A
Tanaka
K
K
Takahashi
H
H
Munekata
M
M
Rao
N N
NN
Kornberg
A
A
D017766:Acid Anhydride Hydrolases / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis*; D002374:Catalase / Q000096:biosynthesis*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018014:Gene Transfer Techniques; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000096:biosynthesis / Q000235:genetics; D010957:Plasmids; D011122:Polyphosphates / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D012808:Sigma Factor / Q000096:biosynthesis*; D013489:Suppression, Genetic; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D011122:Polyphosphates; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D006861:Hydrogen Peroxide; C102664:hydroperoxidase II; D002374:Catalase; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase; D017766:Acid Anhydride Hydrolases; C020137:exopolyphosphatase