RovM, a novel LysR-type regulator of the virulence activator gene rovA, controls cell invasion, virulence and motility of Yersinia pseudotuberculosis.

Abstract

RovA is a MarR-type transcriptional regulator that controls transcription of rovA, the expression of the primary invasive factor invasin and other virulence genes of Yersinia pseudotuberculosis in response to environmental signals. Using a genetic approach to identify regulatory components that negatively influence rovA expression, we identified a new LysR-type regulatory protein, designated RovM, which exhibits homology to the virulence regulator PecT/HexA of plant pathogenic Erwinia species. DNA-binding studies revealed that RovM interacts specifically with a short binding site between promoters P1 and P2 within the rovA regulatory region and negatively modulates rovA transcription in cooperation with the histone-like protein H-NS. The rovM gene itself is under positive autoregulatory control and is significantly induced during growth in minimal media as shown in regulation studies. Disruption of the rovM gene leads to a significant increase of RovA and invasin synthesis and enhances internalization of Y. pseudotuberculosis into host cells. Finally, we show that a Y. pseudotuberculosis rovM mutant is more virulent than wild type and higher numbers of the bacteria are detectable in gut-associated lymphatic tissues and organs in the mouse infection model system. In contrast, elevated levels of the RovM protein, which exert a positive effect on flagellar motility, severely attenuate the ability of Y. pseudotuberculosis to disseminate to deeper tissues. Together, our data show, that RovM is a key regulator implicated in the environmental control of virulence factors, which are crucial for the initiation of a Yersinia infection.

• Authors: Ann Kathrin Heroven, Petra Dersch
• Journal: Molecular microbiology (Mol Microbiol) Vol. 62 Issue 5 Pg. 1469-83 (Dec 2006) ISSN: 0950-382X [Print] England
• PMID: 17074075 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adhesins, Bacterial
• Bacterial Proteins
• RovA protein, Yersinia
• RovM protein, Yersinia pseudotuberculosis
• Trans-Activators
• Transcription Factors
• invasin, Yersinia
• LysR protein, Bacteria

Topics

• Adhesins, Bacterial (metabolism)
• Animals
• Bacterial Proteins (genetics, isolation & purification, metabolism, physiology)
• Gene Expression Regulation, Bacterial
• Genes, Regulator
• Mice
• Mice, Inbred BALB C
• Trans-Activators (genetics, isolation & purification, metabolism)
• Transcription Factors (metabolism, physiology)
• Virulence (genetics)
• Yersinia pseudotuberculosis (genetics, metabolism, pathogenicity)