title: Phosphorylated CpxR restricts production of the RovA global regulator in Yersinia pseudotuberculosis.
abstract: BACKGROUND
  RovA is a global transcriptional regulator of gene expression in pathogenic Yersinia. RovA levels are kept in check by a sophisticated layering of distinct transcriptional and post-transcriptional regulatory mechanisms. In the enteropathogen Y. pseudotuberculosis, we have previously reported that the extracytoplasmic stress sensing CpxA-CpxR two-component regulatory system modulates rovA expression.
  
  
  RESULTS
  In this study, we characterized CpxR phosphorylation (CpxR∼P) in vitro, and determined that phosphorylation was necessary for CpxR to efficiently bind to the PCR-amplified upstream regulatory region of rovA. The precise CpxR∼P binding site was mapped by a nuclease protection assay and directed mutagenesis confirmed that in vivo binding to the rovA promoter inhibits transcription. Reduced RovA production was most pronounced following CpxR∼P accumulation in the Yersinia cytoplasm during chronic Cpx pathway activation and by the indiscriminate phosphodonor action of acetyl phosphate.
  
  
  CONCLUSIONS
  Cpx pathway activation restricts levels of the RovA global regulator. The regulatory influence of CpxR∼P must therefore extend well beyond periplasmic quality control in the Yersinia envelope, to include genes involved in environmental survival and pathogenicity.
authors.affiliation: Department of Molecular Biology, Umeå University, Umeå, Sweden.
authors.forename: Junfa
authors.initials: J
authors.lastname: Liu
authors.forename: Ikenna R
authors.initials: IR
authors.lastname: Obi
authors.forename: Edvin J
authors.initials: EJ
authors.lastname: Thanikkal
authors.forename: Thomas
authors.initials: T
authors.lastname: Kieselbach
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Francis
mesh_terms: D000107:Acetylation; D018829:Adhesins, Bacterial / Q000378:metabolism; D000483:Alleles; D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D003593:Cytoplasm / Q000378:metabolism; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics; D008074:Lipoproteins / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D021241:Spectrometry, Mass, Electrospray Ionization; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014774:Virulence / Q000235:genetics; D015011:Yersinia pseudotuberculosis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008074:Lipoproteins; C095021:NlpE protein, E coli; C405626:RovA protein, Yersinia; D014157:Transcription Factors; C053476:invasin, Yersinia; C085504:CpxR protein, Bacteria; D001224:Aspartic Acid