The CpxRA signal transduction system of Escherichia coli: growth-related autoactivation and control of unanticipated target operons.
In Escherichia coli, the CpxRA two-component signal transduction system senses and responds to aggregated and misfolded proteins in the bacterial envelope. We show that CpxR-P (the phosphorylated form of the cognate response regulator) activates cpxRA expression in conjunction with RpoS, suggesting an involvement of the Cpx system in stationary-phase survival. Engagement of the CpxRA system in functions beyond protein management is indicated by several putative targets identified after a genomic screening for the CpxR-P recognition consensus sequence. Direct negative control of the newly identified targets motABcheAW (specifying motility and chemotaxis) and tsr (encoding the serine chemoreceptor) by CpxR-P was shown by electrophoretic mobility shift analysis and Northern hybridization. The results suggest that the CpxRA system plays a core role in an extensive stress response network in which the coordination of protein turnover and energy conservation may be the unifying element.
De Wulf
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Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Kwon
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O
Lin
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EC
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
D001426:Bacterial Proteins; C489103:CheW protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C063010:MotA protein, Bacteria; C064779:MotB protein, Bacteria; D012808:Sigma Factor; C057635:Tsr protein, Bacteria; C069567:sigma factor KatF protein, Bacteria; C000607604:tsr protein, E coli; C051236:CheW protein, Bacteria; C085504:CpxR protein, Bacteria; D011494:Protein Kinases; C490475:CpxA protein, E coli; C092472:CpxA protein, bacteria