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| Status |
Public on Apr 12, 2010 |
| Title |
Quorum Sensing regulation in Brucella melitensis 16M |
| Organism |
Brucella melitensis bv. 1 str. 16M |
| Experiment type |
Expression profiling by array
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| Summary |
Many pathogenic bacteria use a regulatory process termed Quorum Sensing (QS) to produce and detect small diffusible molecules to synchronize gene expression within a population. In Gram-negative bacteria, the detection and response to these molecules depend on transcriptional regulators belonging to the LuxR family. Such a system have been discovered in the intracellular pathogen Brucella melitensis, a Gram-negative bacteria responsible for brucellosis, a word-wide zoonosis remaining a serious public health concern in endemic countries. Two LuxR-type regulators, VjbR and BabR, have been identified in the genome of this pathogen. The vjbR mutant is highly attenuated in all tested models suggesting a crucial role of QS in the virulence of Brucella. This attenuation is at least due to the involvement of VjbR in the activation of the virB operon coding for a type four secretion system essential for Brucella to reach its intracellular replication compartment. At present, no function has been attributed to BabR. To assess the role of both Brucella QS-regulators, we performed in tandem comparative transcriptomic and proteomic analyses of vjbR and babR mutants. These experiments revealed that 10% of Brucella genome is regulated through those regulators, revealing that QS is a global regulatory system in this intracellular pathogen. The overlapping between BabR and VjbR targets suggest an unexpected cross-talk between these two regulators. Moreover, our results demonstrate that VjbR and BabR regulate many gene and/or proteins involved in stress response, metabolism and virulence. These targets are potentially involved in the adaptation of Brucella to the oxidative, pH and nutritional stresses encountered within the host. These findings highlight the involvement of QS in the virulence of Brucella and led us to suggest that this regulatory system could be implied in the spatial and sequential adaptation of Brucella to the host environment.
Keywords: Quorum Sensing, Comparative gene expression, Brucella melitensis
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| Overall design |
Total RNA were extracted from wt, ∆vjbR and ∆babR, all cultured in triplicate. Triplicate samples of each strain were mixed and one chip was made per strain. Two pairwise comparisons were performed (∆vjbr-wt) and (∆babr-wt). For each comparison, the foldchange was computed as the ratio of intensity averages (mutant/wt).
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| Contributor(s) |
Uzureau S, Lemaire J, Gaigneaux A, De Bolle X, Letesson J |
| Citation(s) |
20387905 |
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| Submission date |
Aug 22, 2007 |
| Last update date |
Mar 17, 2012 |
| Contact name |
Jean-Jacques Letesson |
| E-mail(s) |
aurelie.mirabella@fundp.ac.be
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| Phone |
0032 81724402
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| Fax |
0032 81724297
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| URL |
http://www.fundp.ac.be/facultes/sciences/departements/biologie/recherche/centres/urbm/
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| Organization name |
University of Namur
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| Department |
URBM
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| Street address |
rue de Bruxelles, 61
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| City |
Namur |
| ZIP/Postal code |
5000 |
| Country |
Belgium |
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| Platforms (1) |
| GPL5730 |
FUNDP/URBM_Brucella.melitensis.16M_v.1.0 |
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| Samples (3) |
| GSM219200 |
Brucella melitensis 16M wild type |
| GSM219237 |
Brucella melitensis 16M vjbR mutant strain |
| GSM219239 |
Brucella melitensis 16M babR mutant strain |
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| Relations |
| BioProject |
PRJNA102189 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE8844_RAW.tar |
36.0 Mb |
(http)(custom) |
TAR (of FTR) |
| Processed data included within Sample table |
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