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Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity.
J Bacteriol. 2007 Apr; 189(8):2976-87.JB

Abstract

The small regulatory protein Crl activates sigma(S) (RpoS), the stationary-phase and general stress response sigma factor. Crl has been reported to bind sigma(S) in vitro and to facilitate the formation of RNA polymerase holoenzyme. In Salmonella enterica serovar Typhimurium, Crl is required for the development of the rdar morphotype and transcription initiation of the sigma(S)-dependent genes csgD and adrA, involved in curli and cellulose production. Here, we examined the expression of other sigma(S)-dependent phenotypes and genes in a Deltacrl mutant of Salmonella. Gene fusion analyses and in vitro transcription assays indicate that the magnitude of Crl activation differs between promoters and is highly dependent on sigma(S) levels. We replaced the wild-type rpoS allele in S. enterica serovar Typhimurium strain ATCC 14028 with the rpoS(LT2) allele that shows reduced expression of sigma(S); the result was an increased Crl activation ratio and larger physiological effects of Crl on oxidative, thermal, and acid stress resistance levels during stationary phase. We also found that crl, rpoS, and crl rpoS strains grew better on succinate than did the wild type and expressed the succinate dehydrogenase sdhCDBA operon more strongly. The crl and rpoS(LT2) mutations also increased the competitive fitness of Salmonella in stationary phase. These results show that Crl contributes to negative regulation by sigma(S), a finding consistent with a role for Crl in sigma factor competition via the facilitation of sigma(S) binding to core RNA polymerase.

Authors+Show Affiliations

Institut Pasteur, Unité des Régulations Transcriptionnelles, URA-CNRS 2172, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France. francoise.norel@pasteur.frNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17293430

Citation

Robbe-Saule, Véronique, et al. "Physiological Effects of Crl in Salmonella Are Modulated By sigmaS Level and Promoter Specificity." Journal of Bacteriology, vol. 189, no. 8, 2007, pp. 2976-87.
Robbe-Saule V, Lopes MD, Kolb A, et al. Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity. J Bacteriol. 2007;189(8):2976-87.
Robbe-Saule, V., Lopes, M. D., Kolb, A., & Norel, F. (2007). Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity. Journal of Bacteriology, 189(8), 2976-87.
Robbe-Saule V, et al. Physiological Effects of Crl in Salmonella Are Modulated By sigmaS Level and Promoter Specificity. J Bacteriol. 2007;189(8):2976-87. PubMed PMID: 17293430.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity. AU - Robbe-Saule,Véronique, AU - Lopes,Miguel Dias, AU - Kolb,Annie, AU - Norel,Françoise, Y1 - 2007/02/09/ PY - 2007/2/13/pubmed PY - 2007/5/31/medline PY - 2007/2/13/entrez SP - 2976 EP - 87 JF - Journal of bacteriology JO - J Bacteriol VL - 189 IS - 8 N2 - The small regulatory protein Crl activates sigma(S) (RpoS), the stationary-phase and general stress response sigma factor. Crl has been reported to bind sigma(S) in vitro and to facilitate the formation of RNA polymerase holoenzyme. In Salmonella enterica serovar Typhimurium, Crl is required for the development of the rdar morphotype and transcription initiation of the sigma(S)-dependent genes csgD and adrA, involved in curli and cellulose production. Here, we examined the expression of other sigma(S)-dependent phenotypes and genes in a Deltacrl mutant of Salmonella. Gene fusion analyses and in vitro transcription assays indicate that the magnitude of Crl activation differs between promoters and is highly dependent on sigma(S) levels. We replaced the wild-type rpoS allele in S. enterica serovar Typhimurium strain ATCC 14028 with the rpoS(LT2) allele that shows reduced expression of sigma(S); the result was an increased Crl activation ratio and larger physiological effects of Crl on oxidative, thermal, and acid stress resistance levels during stationary phase. We also found that crl, rpoS, and crl rpoS strains grew better on succinate than did the wild type and expressed the succinate dehydrogenase sdhCDBA operon more strongly. The crl and rpoS(LT2) mutations also increased the competitive fitness of Salmonella in stationary phase. These results show that Crl contributes to negative regulation by sigma(S), a finding consistent with a role for Crl in sigma factor competition via the facilitation of sigma(S) binding to core RNA polymerase. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/17293430/Physiological_effects_of_Crl_in_Salmonella_are_modulated_by_sigmaS_level_and_promoter_specificity_ L2 - http://jb.asm.org/cgi/pmidlookup?view=long&pmid=17293430 DB - PRIME DP - Unbound Medicine ER -