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Project #10540
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#10540 : Characterization of a Salmonella mutant carrying a single amino-acid substitution in the stress sigma factor RpoS
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Name of Applicant : Françoise NOREL
Date of application : 14-11-2017
Unit : Biochemistry of Macromolecular Interactions
Location : Biotop 5th floor
Phone : 0140613122
@ Mail : francoise.norel@pasteur.fr

Project context and summary :

The RpoS/σS sigma subunit of RNA polymerase is the master regulator of the general stress response in many Gram-negative bacteria. σS also contributes to virulence and biofilm formation of the human pathogen Salmonella enterica serovar Typhimurium. We have used RNA-sequencing to unravel the σS-dependent transcriptome in S. Typhimurium ATCC14028. These studies have revealed a major effect of σS on the remodelling of metabolism and membrane functions, and have highlighted the importance of down-regulation of gene expression by σS. More recently, we have used a mass spectrometry-based proteomics approach to explore the wide σS-dependent proteome of ATCC14028. Our proteomics data, and complementary assays, have unravelled the large impact of σS on the Salmonella proteome in stationary phase. As expected, the majority of genes up-regulated by σS at the protein level were also up-regulated at the transcript level. In sharp contrast, our data have revealed a large number of genes down-regulated at the protein level, but not at the transcript level, suggesting that post-transcriptional regulation plays a larger role in σS gene regulation than previously recognized. In this project, we will determine the impact on genome expression of a single amino-acid substitution in RpoS which confers specific phenotypes.


Related team publications :
Lago M, Monteil V, Douche T, Guglielmini J, Criscuolo A, Maufrais C, Matondo M, Norel F. (2017). Proteome remodelling by the stress sigma factor RpoS/σS in Salmonella: identification of small proteins and evidence for post-transcriptional regulation. Sci Rep. 7(1):2127. doi: 10.1038/s41598-017-02362-3.
Lévi-Meyrueis C, Monteil V, Sismeiro O, Dillies MA, Kolb A, Monot M, Dupuy B, Serradas Duarte S, Jagla B, Coppée JY, Beraud M and Norel F (2015). Repressor activity of the RpoS/σS-dependent RNA polymerase requires DNA binding. Nucleic Acids Res. 43:1456-1468
Lévi-Meyrueis C, Monteil V, Sismeiro O, Dillies MA, Monot M, Jagla B, Coppée JY, Dupuy B, Norel F (2014). Expanding the RpoS/σS-network by RNA sequencing and identification of σS-controlled small RNAs in Salmonella. PLoS One. 9:e96918.
Service Delivery
Project Manager : christophe.becavin@pasteur.fr
Project Type : Short
Status : Closed
Global Satisfaction for this application : Pretty Good (4/5)


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