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Alternative sigma factor interactions in Salmonella: sigma and sigma promote antioxidant defences by enhancing sigma levels.
Mol Microbiol. 2005 May; 56(3):811-23.MM

Abstract

Hierarchical interactions between alternative sigma factors control sequential gene expression in Gram-positive bacteria, whereas alternative sigma factors in Gram-negative bacteria are generally regarded to direct expression of discrete gene subsets. In Salmonella enterica serovar Typhimurium (S. Typhimurium), sigma(E) responds to extracytoplasmic stress, whereas sigma(H) responds to heat shock and sigma(S) is induced during nutrient limitation. Deficiency of sigma(E), sigma(H) or sigma(S) increases S. Typhimurium susceptibility to oxidative stress, but an analysis of double and triple mutants suggested that antioxidant actions of sigma(E) and sigma(H) might be dependent on sigma(S). Transcriptional profiling of mutant Salmonella lacking sigma(E) revealed reduced expression of genes dependent on sigma(H) and sigma(S) in addition to sigma(E). Further investigation demonstrated that sigma(E) augments sigma(S) levels during stationary phase via enhanced expression of sigma(H) and the RNA-binding protein Hfq, leading to increased expression of sigma(S)-dependent genes and enhanced resistance to oxidative stress. Maximal expression of the sigma(S)-regulated gene katE required sigma(E) in Salmonella-infected macrophages as well as stationary-phase cultures. Interactions between alternative sigma factors permit the integration of diverse stress signals to produce coordinated genetic responses.

Authors+Show Affiliations

Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15819634

Citation

Bang, Iel-Soo, et al. "Alternative Sigma Factor Interactions in Salmonella: Sigma and Sigma Promote Antioxidant Defences By Enhancing Sigma Levels." Molecular Microbiology, vol. 56, no. 3, 2005, pp. 811-23.
Bang IS, Frye JG, McClelland M, et al. Alternative sigma factor interactions in Salmonella: sigma and sigma promote antioxidant defences by enhancing sigma levels. Mol Microbiol. 2005;56(3):811-23.
Bang, I. S., Frye, J. G., McClelland, M., Velayudhan, J., & Fang, F. C. (2005). Alternative sigma factor interactions in Salmonella: sigma and sigma promote antioxidant defences by enhancing sigma levels. Molecular Microbiology, 56(3), 811-23.
Bang IS, et al. Alternative Sigma Factor Interactions in Salmonella: Sigma and Sigma Promote Antioxidant Defences By Enhancing Sigma Levels. Mol Microbiol. 2005;56(3):811-23. PubMed PMID: 15819634.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Alternative sigma factor interactions in Salmonella: sigma and sigma promote antioxidant defences by enhancing sigma levels. AU - Bang,Iel-Soo, AU - Frye,Jonathan G, AU - McClelland,Michael, AU - Velayudhan,Jyoti, AU - Fang,Ferric C, PY - 2005/4/12/pubmed PY - 2005/8/24/medline PY - 2005/4/12/entrez SP - 811 EP - 23 JF - Molecular microbiology JO - Mol Microbiol VL - 56 IS - 3 N2 - Hierarchical interactions between alternative sigma factors control sequential gene expression in Gram-positive bacteria, whereas alternative sigma factors in Gram-negative bacteria are generally regarded to direct expression of discrete gene subsets. In Salmonella enterica serovar Typhimurium (S. Typhimurium), sigma(E) responds to extracytoplasmic stress, whereas sigma(H) responds to heat shock and sigma(S) is induced during nutrient limitation. Deficiency of sigma(E), sigma(H) or sigma(S) increases S. Typhimurium susceptibility to oxidative stress, but an analysis of double and triple mutants suggested that antioxidant actions of sigma(E) and sigma(H) might be dependent on sigma(S). Transcriptional profiling of mutant Salmonella lacking sigma(E) revealed reduced expression of genes dependent on sigma(H) and sigma(S) in addition to sigma(E). Further investigation demonstrated that sigma(E) augments sigma(S) levels during stationary phase via enhanced expression of sigma(H) and the RNA-binding protein Hfq, leading to increased expression of sigma(S)-dependent genes and enhanced resistance to oxidative stress. Maximal expression of the sigma(S)-regulated gene katE required sigma(E) in Salmonella-infected macrophages as well as stationary-phase cultures. Interactions between alternative sigma factors permit the integration of diverse stress signals to produce coordinated genetic responses. SN - 0950-382X UR - https://www.unboundmedicine.com/medline/citation/15819634/Alternative_sigma_factor_interactions_in_Salmonella:_sigma_and_sigma_promote_antioxidant_defences_by_enhancing_sigma_levels_ L2 - https://doi.org/10.1111/j.1365-2958.2005.04580.x DB - PRIME DP - Unbound Medicine ER -