Role of the Histone-Like Nucleoid Structuring Protein in the Regulation of rpoS and RpoS-Dependent Genes in Vibrio cholerae

• DOI: 10.1128/jb.00360-08
• Publication Date: 2008-09-13T00:44:14Z
• Authors: Anisia J. Silva; Syed Zafar Sultan; Weili Liang; Jorge A. Benitez
• Keywords: rpoS; Sigma factor; Wild type

ABSTRACT Production of the Zn-metalloprotease hemagglutinin (HA)/protease by Vibrio cholerae has been reported to enhance enterotoxicity in rabbit ileal loops and reactogenicity live cholera vaccine candidates. Expression HA/protease requires alternate sigma factor σ S (RpoS), encoded rpoS . The histone-like nucleoid structuring protein (H-NS) shown repress expression Escherichia coli In V. strains classical biotype, H-NS silence virulence gene expression. this study we examined role motility an El Tor biotype strain constructing a Δ hns mutant. mutant exhibited multiple phenotypes, such as production toxin nonpermissive LB medium, reduced resistance high osmolarity, enhanced low pH hydrogen peroxide, motility. Depletion overexpression dominant-negative allele or deletion resulted diminished HA/protease. Epistasis analysis , mutants, RpoS reporter fusions, quantitative reverse transcription-PCR measurements, ectopic mutants showed that posttranscriptionally enhances lower degree levels flaA flaC cheR - 2 motX mRNAs than wild type. Comparison mRNA abundances these genes wild-type, revealed had more severe negative effect on their Interestingly, background higher suggesting represses absence Finally, show cyclic AMP receptor act along same pathway positively affect