» Articles » PMID: 20400542

Identification of the Quorum-sensing Target DNA Sequence and N-Acyl Homoserine Lactone Responsiveness of the Brucella Abortus VirB Promoter

Overview
Journal J Bacteriol
Specialty Microbiology
Date 2010 Apr 20
PMID 20400542
Citations 21
Authors
Affiliations
Soon will be listed here.
Abstract

VjbR is a LuxR-type quorum-sensing (QS) regulator that plays an essential role in the virulence of the intracellular facultative pathogen Brucella, the causative agent of brucellosis. It was previously described that VjbR regulates a diverse group of genes, including the virB operon. The latter codes for a type IV secretion system (T4SS) that is central for the pathogenesis of Brucella. Although the regulatory role of VjbR on the virB promoter (P(virB)) was extensively studied by different groups, the VjbR-binding site had not been identified so far. Here, we identified the target DNA sequence of VjbR in P(virB) by DNase I footprinting analyses. Surprisingly, we observed that VjbR specifically recognizes a sequence that is identical to a half-binding site of the QS-related regulator MrtR of Mesorhizobium tianshanense. As shown by DNase I footprinting and electrophoretic mobility shift assays, generation of a palindromic MrtR-like-binding site in P(virB) increased both the affinity and the stability of the VjbR-DNA complex, which confirmed that the QS regulator of Brucella is highly related to that of M. tianshanense. The addition of N-dodecanoyl homoserine lactone dissociated VjbR from the promoter, which confirmed previous reports that indicated a negative effect of this signal on the VjbR-mediated activation of P(virB). Our results provide new molecular evidence for the structure of the virB promoter and reveal unusual features of the QS target DNA sequence of the main regulator of virulence in Brucella.

Citing Articles

Genome-wide analysis of Brucella melitensis growth in spleen of infected mice allows rational selection of new vaccine candidates.

Barbieux E, Potemberg G, Stubbe F, Fraikin A, Poncin K, Reboul A PLoS Pathog. 2024; 20(8):e1012459.

PMID: 39186777 PMC: 11346958. DOI: 10.1371/journal.ppat.1012459.


MsmR1, a global transcription factor, regulates polymyxin synthesis and carbohydrate metabolism in SC2.

Zhao D, Li H, Cui Y, Tang S, Wang C, Du B Front Microbiol. 2022; 13:1039806.

PMID: 36483206 PMC: 9722767. DOI: 10.3389/fmicb.2022.1039806.


Uncovering the Hidden Credentials of Virulence.

Roop 2nd R, Barton I, Hopersberger D, Martin D Microbiol Mol Biol Rev. 2021; 85(1).

PMID: 33568459 PMC: 8549849. DOI: 10.1128/MMBR.00021-19.


Depends on l-Serine Biosynthesis for Intracellular Proliferation.

Revora V, Marchesini M, Comerci D Infect Immun. 2019; 88(2).

PMID: 31740531 PMC: 6977118. DOI: 10.1128/IAI.00840-19.


Relationship Between Quorum Sensing and Secretion Systems.

Pena R, Blasco L, Ambroa A, Gonzalez-Pedrajo B, Fernandez-Garcia L, Lopez M Front Microbiol. 2019; 10:1100.

PMID: 31231316 PMC: 6567927. DOI: 10.3389/fmicb.2019.01100.


References
1.
Sieira R, Comerci D, Pietrasanta L, Ugalde R . Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon. Mol Microbiol. 2004; 54(3):808-22. DOI: 10.1111/j.1365-2958.2004.04316.x. View

2.
Delrue R, Deschamps C, Leonard S, Nijskens C, Danese I, Schaus J . A quorum-sensing regulator controls expression of both the type IV secretion system and the flagellar apparatus of Brucella melitensis. Cell Microbiol. 2005; 7(8):1151-61. DOI: 10.1111/j.1462-5822.2005.00543.x. View

3.
Rambow-Larsen A, Rajashekara G, Petersen E, Splitter G . Putative quorum-sensing regulator BlxR of Brucella melitensis regulates virulence factors including the type IV secretion system and flagella. J Bacteriol. 2008; 190(9):3274-82. PMC: 2347389. DOI: 10.1128/JB.01915-07. View

4.
Miller M, Bassler B . Quorum sensing in bacteria. Annu Rev Microbiol. 2001; 55:165-99. DOI: 10.1146/annurev.micro.55.1.165. View

5.
Engebrecht J, Nealson K, Silverman M . Bacterial bioluminescence: isolation and genetic analysis of functions from Vibrio fischeri. Cell. 1983; 32(3):773-81. DOI: 10.1016/0092-8674(83)90063-6. View