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The Salmonella typhimurium katF (rpoS) gene: cloning, nucleotide sequence, and regulation of spvR and spvABCD virulence plasmid genes.
J Bacteriol. 1994 Nov; 176(22):6852-60.JB

Abstract

The spv region of Salmonella virulence plasmids is essential for the development of a systemic infection in mice. Transcriptional activation of the spvABCD operon occurs during stationary growth phase and is mediated by the regulatory gene product SpvR. We have previously shown that expression of a spvRAB'-cat fusion in Escherichia coli was dependent on the katF (rpoS) locus which encodes an alternative sigma factor (sigma S). The katF gene from Salmonella typhimurium has been cloned, sequenced, and used to construct Salmonella katF mutants by allelic replacement. Using these mutants, we demonstrated by mRNA and gene fusion analyses that sigma S, in conjunction with SpvR, controls the transcription of the regulatory gene spvR. In a second series of experiments, we sought to clarify the relationship between sigma S and SpvR in the control of spvABCD transcription. It was shown that expression of a transcriptional spvAB'-lacZ fusion could be restored in E. coli and Salmonella katF mutants when spvR was expressed in trans from an exogenous promoter. Moreover, identical spvA mRNA startpoints were detected in katF+ and katF strains. These results indicate that the reduction of spvABCD transcription in katF mutants is mainly due to decreased expression of spvR. Finally, mouse inoculation studies with S. typhimurium katF mutants of both wild-type and virulence plasmid-cured strains suggest that katF contributes to Salmonella virulence via the regulation of chromosomal genes in addition to that of spv genes.

Authors+Show Affiliations

Unité des Entérobactéries, Institut Pasteur, Institut National de la Santé et de la Recherche Médicale, Paris, France.No 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

7961444

Citation

Kowarz, L, et al. "The Salmonella Typhimurium katF (rpoS) Gene: Cloning, Nucleotide Sequence, and Regulation of spvR and spvABCD Virulence Plasmid Genes." Journal of Bacteriology, vol. 176, no. 22, 1994, pp. 6852-60.
Kowarz L, Coynault C, Robbe-Saule V, et al. The Salmonella typhimurium katF (rpoS) gene: cloning, nucleotide sequence, and regulation of spvR and spvABCD virulence plasmid genes. J Bacteriol. 1994;176(22):6852-60.
Kowarz, L., Coynault, C., Robbe-Saule, V., & Norel, F. (1994). The Salmonella typhimurium katF (rpoS) gene: cloning, nucleotide sequence, and regulation of spvR and spvABCD virulence plasmid genes. Journal of Bacteriology, 176(22), 6852-60.
Kowarz L, et al. The Salmonella Typhimurium katF (rpoS) Gene: Cloning, Nucleotide Sequence, and Regulation of spvR and spvABCD Virulence Plasmid Genes. J Bacteriol. 1994;176(22):6852-60. PubMed PMID: 7961444.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The Salmonella typhimurium katF (rpoS) gene: cloning, nucleotide sequence, and regulation of spvR and spvABCD virulence plasmid genes. AU - Kowarz,L, AU - Coynault,C, AU - Robbe-Saule,V, AU - Norel,F, PY - 1994/11/1/pubmed PY - 1994/11/1/medline PY - 1994/11/1/entrez SP - 6852 EP - 60 JF - Journal of bacteriology JO - J Bacteriol VL - 176 IS - 22 N2 - The spv region of Salmonella virulence plasmids is essential for the development of a systemic infection in mice. Transcriptional activation of the spvABCD operon occurs during stationary growth phase and is mediated by the regulatory gene product SpvR. We have previously shown that expression of a spvRAB'-cat fusion in Escherichia coli was dependent on the katF (rpoS) locus which encodes an alternative sigma factor (sigma S). The katF gene from Salmonella typhimurium has been cloned, sequenced, and used to construct Salmonella katF mutants by allelic replacement. Using these mutants, we demonstrated by mRNA and gene fusion analyses that sigma S, in conjunction with SpvR, controls the transcription of the regulatory gene spvR. In a second series of experiments, we sought to clarify the relationship between sigma S and SpvR in the control of spvABCD transcription. It was shown that expression of a transcriptional spvAB'-lacZ fusion could be restored in E. coli and Salmonella katF mutants when spvR was expressed in trans from an exogenous promoter. Moreover, identical spvA mRNA startpoints were detected in katF+ and katF strains. These results indicate that the reduction of spvABCD transcription in katF mutants is mainly due to decreased expression of spvR. Finally, mouse inoculation studies with S. typhimurium katF mutants of both wild-type and virulence plasmid-cured strains suggest that katF contributes to Salmonella virulence via the regulation of chromosomal genes in addition to that of spv genes. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/7961444/The_Salmonella_typhimurium_katF__rpoS__gene:_cloning_nucleotide_sequence_and_regulation_of_spvR_and_spvABCD_virulence_plasmid_genes_ L2 - http://jb.asm.org/cgi/pmidlookup?view=long&pmid=7961444 DB - PRIME DP - Unbound Medicine ER -