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Hha is a negative modulator of transcription of hilA, the Salmonella enterica serovar Typhimurium invasion gene transcriptional activator.
J Bacteriol. 2001 Nov; 183(22):6620-9.JB

Abstract

An early step in the establishment of Salmonella enterica serovar Typhimurium murine infection is the penetration of the intestinal mucosa of the small intestine. The majority of the genes responsible for the Salmonella invasive phenotype are encoded on Salmonella pathogenicity island 1, and their transcription is controlled by the hilA transcriptional activator. The expression of hilA is regulated by environmental signals including oxygen, osmolarity, pH, and growth phase such that the presence of any one suboptimal condition results in repression of hilA expression and the invasive phenotype. We have conducted a search for negative regulators of hilA by introduction of a Salmonella enterica serovar Typhimurium chromosomal DNA gene bank into a Salmonella enterica serovar Typhimurium hilA::Tn5lacZY reporter strain. This screen has identified the hha gene as a regulator that exerts a negative influence on hilA expression. Plasmid-encoded hha significantly reduces hilA::Tn5lacZY chromosomal expression, as well as expression of the invasion genes invF, prgH, and sipC. An hha null mutation results in substantial derepression of both chromosomally encoded and plasmid-encoded hilA::Tn5lacZY expression. Introduction of plasmid-encoded hha into strain SL1344 results in attenuation of invasion using in vitro and in vivo assays. Importantly, purified Hha protein was found to bind to a hilA DNA promoter fragment, suggesting that the regulatory activity of the Hha protein occurs at the hilA promoter. These data add detail to the developing model of the regulation of Salmonella invasion genes.

Authors+Show Affiliations

Department of Microbiology, University of Iowa School of Medicine, Iowa City 52242, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

11673432

Citation

Fahlen, T F., et al. "Hha Is a Negative Modulator of Transcription of hilA, the Salmonella Enterica Serovar Typhimurium Invasion Gene Transcriptional Activator." Journal of Bacteriology, vol. 183, no. 22, 2001, pp. 6620-9.
Fahlen TF, Wilson RL, Boddicker JD, et al. Hha is a negative modulator of transcription of hilA, the Salmonella enterica serovar Typhimurium invasion gene transcriptional activator. J Bacteriol. 2001;183(22):6620-9.
Fahlen, T. F., Wilson, R. L., Boddicker, J. D., & Jones, B. D. (2001). Hha is a negative modulator of transcription of hilA, the Salmonella enterica serovar Typhimurium invasion gene transcriptional activator. Journal of Bacteriology, 183(22), 6620-9.
Fahlen TF, et al. Hha Is a Negative Modulator of Transcription of hilA, the Salmonella Enterica Serovar Typhimurium Invasion Gene Transcriptional Activator. J Bacteriol. 2001;183(22):6620-9. PubMed PMID: 11673432.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Hha is a negative modulator of transcription of hilA, the Salmonella enterica serovar Typhimurium invasion gene transcriptional activator. AU - Fahlen,T F, AU - Wilson,R L, AU - Boddicker,J D, AU - Jones,B D, PY - 2001/10/24/pubmed PY - 2002/1/5/medline PY - 2001/10/24/entrez SP - 6620 EP - 9 JF - Journal of bacteriology JO - J Bacteriol VL - 183 IS - 22 N2 - An early step in the establishment of Salmonella enterica serovar Typhimurium murine infection is the penetration of the intestinal mucosa of the small intestine. The majority of the genes responsible for the Salmonella invasive phenotype are encoded on Salmonella pathogenicity island 1, and their transcription is controlled by the hilA transcriptional activator. The expression of hilA is regulated by environmental signals including oxygen, osmolarity, pH, and growth phase such that the presence of any one suboptimal condition results in repression of hilA expression and the invasive phenotype. We have conducted a search for negative regulators of hilA by introduction of a Salmonella enterica serovar Typhimurium chromosomal DNA gene bank into a Salmonella enterica serovar Typhimurium hilA::Tn5lacZY reporter strain. This screen has identified the hha gene as a regulator that exerts a negative influence on hilA expression. Plasmid-encoded hha significantly reduces hilA::Tn5lacZY chromosomal expression, as well as expression of the invasion genes invF, prgH, and sipC. An hha null mutation results in substantial derepression of both chromosomally encoded and plasmid-encoded hilA::Tn5lacZY expression. Introduction of plasmid-encoded hha into strain SL1344 results in attenuation of invasion using in vitro and in vivo assays. Importantly, purified Hha protein was found to bind to a hilA DNA promoter fragment, suggesting that the regulatory activity of the Hha protein occurs at the hilA promoter. These data add detail to the developing model of the regulation of Salmonella invasion genes. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/11673432/Hha_is_a_negative_modulator_of_transcription_of_hilA_the_Salmonella_enterica_serovar_Typhimurium_invasion_gene_transcriptional_activator_ L2 - https://journals.asm.org/doi/10.1128/JB.183.22.6620-6629.2001?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -