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| Status |
Public on Jul 08, 2013 |
| Title |
Global Rsh-dependent transcription profile of Brucella suis during stringent response unravels adaptation to nutrient starvation and cross-talk with other stress responses. |
| Platform organism |
Brucella melitensis |
| Sample organism |
Brucella suis 1330 |
| Experiment type |
Expression profiling by array
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| Summary |
In the intracellular pathogen Brucella spp., the activation of the stringent response, a global regulatory network providing rapid adaptation to a variety of growth-affecting stress conditions such as nutrient deficiency, is essential for replication in the host. A single, bi-functional enzyme Rsh catalyzes synthesis and hydrolysis of the alarmone (p)ppGpp, responsible for differential gene expression under stringent conditions. cDNA microarray analysis allowed characterization of the transcriptional profiles of the B. suis 1330 wild-type and rsh mutant in a synthetic minimal medium, partially mimicking the nutrient-poor environment of the intramacrophagic vacuole. A total of 379 genes (11.6% of the genome) were differentially expressed in a rsh-dependent manner, of which 52% were up-regulated and 48% were down-regulated. The pleiotropic character of the response was confirmed, as the genes encoded factors belonging to various functional groups, comprising an important number of transcriptional regulators, cell envelope proteins, stress factors, transport systems, and energy metabolism proteins. Several virulence genes were under the positive control of (p)ppGpp. Methionine was the only amino acid whose biosynthesis was absolutely dependent on stringent response in B. suis. The study illustrated the complexity of the processes involved in adaptation to nutrient starvation, and contributed to a better understanding of the correlation between stringent response and Brucella virulence. Most interestingly, it clearly indicated (p)ppGpp-dependent cross-talk between at least three stress responses playing a central role in Brucella adaptation to the host: nutrient, oxidative, and low-oxygen stress.
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| Overall design |
Two-condition experiment, wild-type against rsh mutant. Biological replicates: 4 wild-type, 4 rsh mutant, independently grown in minimal medium (under nutrient starvation condition) and harvested. One replicate per array.
Please note that Channel 1 (Cy3) on each hybridization was a universal reference (Uref) used as a reference point to merge two (2 channel arrays) into a virtual 2 channel array with wild-type versus rsh mutant.
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| Contributor(s) |
Hanna N, Ouahrani-Bettache S, Drake KL, Adams LG, Köhler S, Occhialini A |
| Citation(s) |
23834488 |
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| Submission date |
Feb 26, 2013 |
| Last update date |
Jul 11, 2013 |
| Contact name |
Stephan Kohler |
| E-mail(s) |
stephan.kohler@cpbs.cnrs.fr
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| Organization name |
CNRS
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| Lab |
UMR 5236
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| Street address |
1919 Route de Mende
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| City |
Montpellier |
| ZIP/Postal code |
34095 |
| Country |
France |
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| Platforms (1) |
| GPL7612 |
ASU Brucella melitensis 13K oligo array v1.0 |
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| Samples (4)
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| Relations |
| BioProject |
PRJNA191082 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE44688_RAW.tar |
3.7 Mb |
(http)(custom) |
TAR (of TXT) |
| Processed data included within Sample table |
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