Protein level identification of the Listeria monocytogenes Sigma H, Sigma L, and Sigma C regulons

BMC Microbiology

Research Article

Sana Mujahid¹  Martin Wiedmann¹  Kathryn J Boor¹  Renato H Orsi¹ 

[1] Department of Food Science, Cornell University, 412 Stocking Hall, Ithaca, NY, USA;

关键词: Listeria monocytogenes;    Alternative sigma factors;    Quantitative proteomics;   

DOI  :  10.1186/1471-2180-13-156

 received in 2013-02-07, accepted in 2013-07-04,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundTranscriptional regulation by alternative sigma (σ) factors represents an important mechanism that allows bacteria to rapidly regulate transcript and protein levels in response to changing environmental conditions. While the role of the alternative σ factor σB has been comparatively well characterized in L. monocytogenes, our understanding of the roles of the three other L. monocytogenes alternative σ factors is still limited. In this study, we employed a quantitative proteomics approach using Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) to characterize the L. monocytogenes σL, σH, and σC protein regulons. Proteomic comparisons used a quadruple alternative σ factor mutant strain (ΔBCHL) and strains expressing a single alternative σ factor (i.e., σL, σH, and σC; strains ΔBCH, ΔBCL, and ΔBHL) to eliminate potential redundancies between σ factors.ResultsAmong the three alternative σ factors studied here, σH provides positive regulation for the largest number of proteins, consistent with previous transcriptomic studies, while σL appears to contribute to negative regulation of a number of proteins. σC was found to regulate a small number of proteins in L. monocytogenes grown to stationary phase at 37°C. Proteins identified as being regulated by multiple alternative σ factors include MptA, which is a component of a PTS system with a potential role in regulation of PrfA activity.ConclusionsThis study provides initial insights into global regulation of protein production by the L. monocytogenes alternative σ factors σL, σH, and σC. While, among these σ factors, σH appears to positively regulate the largest number of proteins, we also identified PTS systems that appear to be co-regulated by multiple alternative σ factors. Future studies should not only explore potential roles of alternative σ factors in activating a “cascade” of PTS systems that potentially regulate PrfA, but also may want to explore the σL and σC regulons under different environmental conditions to identify conditions where these σ factors may regulate larger numbers of proteins or genes.

【 授权许可】

Unknown   
© Mujahid et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.