The RovA regulons of <i>Yersinia enterocolitica</i> and <i>Yersinia pestis</i> are distinct: evidence that many RovA‐regulated genes were acquired more recently than the core genome

Cathelyn, Jason S.; Ellison, Damon W.; Hinchliffe, Stewart J.; Wren, Brendan W.; Miller, Virginia L.

doi:10.1111/j.1365-2958.2007.05907.x

Cited by 72 publications

(80 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…RovA is one of the best-characterized transcriptional regulators of yersiniae. It has been proposed that RovA behaves as an anti-H-NS factor to alleviate H-NS-imposed repression (15,22). Consistent with this model, in YeO8 H-NS represses inv expression at 37°C whereas at 21°C RovA overcomes H-NS-imposed repression, hence allowing inv expression.…”

Section: Effects Of Lps Temperature-dependent Variations In Susceptibsupporting

confidence: 68%

Molecular Basis of Yersinia enterocolitica Temperature-Dependent Resistance to Antimicrobial Peptides

et al. 2012

View full text Add to dashboard Cite

Antimicrobial peptides (APs) belong to the arsenal of weapons of the innate immune system against infections. In the case of Gram-negative bacteria, APs interact with the anionic lipid A moiety of the lipopolysaccharide (LPS). In yersiniae most virulence factors are temperature regulated. Studies from our laboratory demonstrated that Yersinia enterocolitica is more susceptible to polymyxin B, a model AP, when grown at 37°C than at 22°C (J. A. Bengoechea, R. Díaz, and I. Moriyón, Infect. Immun. 64:4891–4899, 1996), and here we have extended this observation to other APs, not structurally related to polymyxin B. Mechanistically, we demonstrate that the lipid A modifications with aminoarabinose and palmitate are downregulated at 37°C and that they contribute to AP resistance together with the LPS O-polysaccharide. Bacterial loads of lipid A mutants in Peyer's patches, liver, and spleen of orogastrically infected mice were lower than those of the wild-type strain at 3 and 7 days postinfection. PhoPQ and PmrAB two-component systems govern the expression of the loci required to modify lipid A with aminoarabinose and palmitate, and their expressions are also temperature regulated. Our findings support the notion that the temperature-dependent regulation of loci controlling lipid A modifications could be explained by H-NS-dependent negative regulation alleviated by RovA. In turn, our data also demonstrate that PhoPQ and PmrAB regulate positively the expression of rovA , the effect of PhoPQ being more important. However, rovA expression reached wild-type levels in the phoPQ pmrAB mutant background, hence indicating the existence of an unknown regulatory network controlling rovA expression in this background.

show abstract

Section: Effects Of Lps Temperature-dependent Variations In Susceptibsupporting

confidence: 68%

Molecular Basis of Yersinia enterocolitica Temperature-Dependent Resistance to Antimicrobial Peptides

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The regulatory cross talk between the genes might therefore be a good model for studying the evolution of regulatory networks in bacteria. There is evidence that H-NS acts as a silencer of laterally acquired genes in bacteria and that in Yersinia the regulator RovA is able to relieve silencing by H-NS by competing for binding at promoter regions (2,(6)(7)(8)14). Our studies show that H-NS, but not RovA, affects the expression of hreP, at least in E. coli, in a temperature-dependent manner.…”

Section: Discussionmentioning

confidence: 60%

“…In a recent study (2), it was shown that a large proportion of RovAactivated genes are repressed by H-NS. We used RovA overproduction from the P BAD promoter as a tool to analyze the effect of RovA on gene transcription in an hreP-lacZYA reporter strain (GHY19).…”

Section: Resultsmentioning

confidence: 99%

A Regulatory Network Controls Expression of the In Vivo-Expressed HreP Protease of Yersinia enterocolitica

et al. 2009

View full text Add to dashboard Cite

The human enteropathogen Yersinia enterocolitica survives and replicates in the lymphoid tissues of its host. Previous in vivo analyses of gene expression revealed that various chromosomal genes are expressed at this stage of infection, but not in vitro. One of these, termed hreP, encodes a protease that is necessary for full virulence of Y. enterocolitica. Using transposon mutagenesis, we identified three genes, pypA, pypB, and pypC, as positive regulators of hreP transcription. PypA is an inner membrane protein with no significant similarity to any known proteins; PypB is a ToxR-like transmembrane transcriptional regulator; and PypC is a cytoplasmic transcriptional regulator with an OmpR-like winged helix-turn-helix DNA binding motif. We show that all Pyp proteins are able to activate hreP independently of each other and that PypB and PypC interact directly with the hreP promoter region. Furthermore, pypB and pypC are autoregulated and regulate each other. Additional data indicate that transcription of hreP is repressed by the histone-like nucleoid-structuring protein H-NS in a temperature-dependent manner. Our data reveal a new regulatory network that might have implications for the controlled expression of further virulence-associated functions in Yersinia.

show abstract

“…Nearly all RovA (SlyA)-activated genes in Yersinia spp. are repressed by H-NS, and most RovA-bound promoters are also bound by H-NS [61]. The Y. enterocolitica inv gene encoding invasin is repressed by H-NS in conjunction with Hha (called YmoA in Y. enterocolitica) [62] and derepressed by RovA.…”

Section: Counter-silencing Of H-ns and Its Functional Consequencesmentioning

confidence: 99%

New insights into transcriptional regulation by H-NS

Fang

Rimsky

2008

Current Opinion in Microbiology

186

173

View full text Add to dashboard Cite

H-NS, a nucleoid-associated DNA-binding protein of enteric bacteria, was discovered thirty-five years ago and subsequently found to exert widespread and highly pleiotropic effects on gene regulation. H-NS binds to high-affinity sites and spreads along adjacent AT-rich DNA to silence transcription. Preferential binding to sequences with higher AT-content than the resident genome allows H-NS to repress the expression of foreign DNA in a process known as "xenogeneic silencing." Counter-silencing by a variety of mechanisms facilitates the evolutionary acquisition of horizontally transferred genes and their integration into pre-existing regulatory networks. This review will highlight recent insights into the mechanism and biological importance of H-NS-DNA interactions. H-NS--A Nucleoid ProteinH-NS is an abundant DNA-binding protein implicated in the organization of the bacterial chromosome [1]. H-NS and other nucleoid-associated proteins can affect DNA topology at specific loci, thereby modulating gene transcription. Binding by these proteins is proposed to selectively direct supercoiling effects to promoters [2•]. Mutation of hns alters the responsiveness of transcription to changes in DNA superhelicity. Regulatory effects of supercoiling are linked to metabolic and environmental conditions. Thus, H-NS has been viewed as a nucleoid structuring protein with global effects on gene expression [3].H-NS exists primarily as a dimer at low concentrations but can multimerize into higher order complexes [4,5] that form bridges between adjacent DNA helices [6]. Optical tweezers have been used to demonstrate that H-NS dimers or multimers can simultaneously interact with separate DNA binding sites [7••]. H-NS-coated DNA is not self-interactive, suggesting that dimerization or oligomerization must precede DNA binding for bridging to occur. Force measurements suggest that transcription barriers created by H-NS binding are weak (∼7 pN) and readily overcome, so that H-NS oligomers pose only a relative barrier to translocating RNA polymerase. DNA bridging is a conserved feature of H-NS homologs found in most gram-negative bacteria [8] that appears to constrain large DNA loops [9••] and helps to account for the effects of H-NS on transcription. However, it must be noted that the relationship between bridging as a general effect and the silencing of specific promoters is not yet clear.H-NS is more appropriately viewed as a determinant of chromosomal architecture rather than as a general structural component. The analysis of nucleoids treated with urea suggests that *Corresponding Author : Tel 206-275-0966, Fax 206-616-1575, e-mail : fcfang@u.washington.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production proce...

show abstract

The RovA regulons of Yersinia enterocolitica and Yersinia pestis are distinct: evidence that many RovA‐regulated genes were acquired more recently than the core genome

Abstract: Summary RovA is a transcriptional activator of

Cited by 72 publications

References 90 publications

Molecular Basis of Yersinia enterocolitica Temperature-Dependent Resistance to Antimicrobial Peptides

Molecular Basis of Yersinia enterocolitica Temperature-Dependent Resistance to Antimicrobial Peptides

A Regulatory Network Controls Expression of the In Vivo-Expressed HreP Protease of Yersinia enterocolitica

New insights into transcriptional regulation by H-NS

Contact Info

Product

Resources

About