title: ClpXP controls the expression of LEE genes in enterohaemorrhagic Escherichia coli.
abstract: Enterohaemorrhagic Escherichia coli (EHEC) contains a 36-kb pathogenicity island termed the locus of enterocyte effacement (LEE), which encodes a type III secretion system (TTSS) and virulence proteins. In this paper, we show that the O157:H7 Sakai clpPX mutant strongly impaired the secretion of virulence proteins by TTSS and repressed transcription from all the LEE promoters. The rpoS mutation in O157:H7 Sakai enhanced the transcription from all the LEE promoters and the secretion of virulence proteins, and it could partially suppress the defects of the clpPX mutation. These data indicate that the O157:H7 Sakai ClpXP protease is a positive regulator for LEE expression and that this regulation occurs by two pathways: the sigma(S)-dependent and -independent pathways.
authors.affiliation: Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan. tomoyasu@p.chiba-u.ac.jp
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Tomoyasu
authors.forename: Akiko
authors.initials: A
authors.lastname: Takaya
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Handa
authors.forename: Kiyonobu
authors.initials: K
authors.lastname: Karata
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism*; D019453:Escherichia coli O157 / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D044404:Genomic Islands; D006801:Humans; D009154:Mutation; D010750:Phosphoproteins / Q000235:genetics*; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C457340:LEE protein, E coli; D010750:Phosphoproteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; C483573:ClpXP protease, E coli; D049071:Endopeptidase Clp