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The fimYZ genes regulate Salmonella enterica Serovar Typhimurium invasion in addition to type 1 fimbrial expression and bacterial motility.
Infect Immun. 2005 Mar; 73(3):1377-85.II

Abstract

An important step in Salmonella enterica serovar Typhimurium virulence is the ability to invade the intestinal epithelium. The invasion process requires a large number of genes encoded on Salmonella pathogenicity island 1 (SPI-1) at centisome 63 as well as genes located in other positions throughout the chromosome. Expression of the invasive phenotype is tightly regulated by environmental cues that are processed by a complex regulatory scheme. A central player in the invasion regulatory pathway is the HilA protein, which is transcriptional activator belonging to the OmpR/ToxR family. A number of positive regulators (hilC, hilD, fis, sirA/barA, csrAB, phoBR, fadD, envZ/ompR, and fliZ) and negative regulators (hha, hilE, lon, ams, phoPc and pag) have been identified that are able to alter expression of hilA transcription. Recent work has found that hilA transcription requires the HilD protein for activation. Other work has emphasized the importance of HilE as a negative regulator of hilA. Overexpression of hilE superrepresses hilA transcription, as well as the invasive phenotype. Two-hybrid experiments suggest that HilE exerts its regulatory influence on hilA through protein-protein interactions with HilD as the protein does not bind to the hilA promoter nor does it affect hilD transcription. As it seems likely that hilE plays an important role in translating environmental signals into invasion gene regulation, we have attempted to identify how the hilE gene itself is regulated. Our results indicate that the fimYZ genes, response regulatory proteins involved in type 1 fimbrial gene expression and recently implicated in motility gene regulation, are important activators of hilE expression. These findings indicate that invasion gene expression is coregulated with motility and adherence and provide experimental evidence that the expression of these virulence phenotypes is a subset of the overall regulation of bacterial physiology.

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Authors+Show Affiliations

Baxter MA
Department of Microbiology, Roy J. and Lucille A. Carver School of Medicine, University of Iowa, Iowa City, IA 52242-1109. bradley-jones@uiowa.edu.
Jones BD
No affiliation info available

MeSH

Bacterial AdhesionBacterial ProteinsFimbriae, BacterialGene DeletionGene Expression Regulation, BacterialHumansMovementRepressor ProteinsSalmonella typhimuriumSignal TransductionTrans-ActivatorsTranscription FactorsTranscription, GeneticTwo-Hybrid System Techniques

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15731035

Citation

Baxter, M Aaron, and Bradley D. Jones. "The fimYZ Genes Regulate Salmonella Enterica Serovar Typhimurium Invasion in Addition to Type 1 Fimbrial Expression and Bacterial Motility." Infection and Immunity, vol. 73, no. 3, 2005, pp. 1377-85.
Baxter MA, Jones BD. The fimYZ genes regulate Salmonella enterica Serovar Typhimurium invasion in addition to type 1 fimbrial expression and bacterial motility. Infect Immun. 2005;73(3):1377-85.
Baxter, M. A., & Jones, B. D. (2005). The fimYZ genes regulate Salmonella enterica Serovar Typhimurium invasion in addition to type 1 fimbrial expression and bacterial motility. Infection and Immunity, 73(3), 1377-85.
Baxter MA, Jones BD. The fimYZ Genes Regulate Salmonella Enterica Serovar Typhimurium Invasion in Addition to Type 1 Fimbrial Expression and Bacterial Motility. Infect Immun. 2005;73(3):1377-85. PubMed PMID: 15731035.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The fimYZ genes regulate Salmonella enterica Serovar Typhimurium invasion in addition to type 1 fimbrial expression and bacterial motility. AU - Baxter,M Aaron, AU - Jones,Bradley D, PY - 2005/2/26/pubmed PY - 2005/4/2/medline PY - 2005/2/26/entrez SP - 1377 EP - 85 JF - Infection and immunity JO - Infect Immun VL - 73 IS - 3 N2 - An important step in Salmonella enterica serovar Typhimurium virulence is the ability to invade the intestinal epithelium. The invasion process requires a large number of genes encoded on Salmonella pathogenicity island 1 (SPI-1) at centisome 63 as well as genes located in other positions throughout the chromosome. Expression of the invasive phenotype is tightly regulated by environmental cues that are processed by a complex regulatory scheme. A central player in the invasion regulatory pathway is the HilA protein, which is transcriptional activator belonging to the OmpR/ToxR family. A number of positive regulators (hilC, hilD, fis, sirA/barA, csrAB, phoBR, fadD, envZ/ompR, and fliZ) and negative regulators (hha, hilE, lon, ams, phoPc and pag) have been identified that are able to alter expression of hilA transcription. Recent work has found that hilA transcription requires the HilD protein for activation. Other work has emphasized the importance of HilE as a negative regulator of hilA. Overexpression of hilE superrepresses hilA transcription, as well as the invasive phenotype. Two-hybrid experiments suggest that HilE exerts its regulatory influence on hilA through protein-protein interactions with HilD as the protein does not bind to the hilA promoter nor does it affect hilD transcription. As it seems likely that hilE plays an important role in translating environmental signals into invasion gene regulation, we have attempted to identify how the hilE gene itself is regulated. Our results indicate that the fimYZ genes, response regulatory proteins involved in type 1 fimbrial gene expression and recently implicated in motility gene regulation, are important activators of hilE expression. These findings indicate that invasion gene expression is coregulated with motility and adherence and provide experimental evidence that the expression of these virulence phenotypes is a subset of the overall regulation of bacterial physiology. SN - 0019-9567 UR - https://www.unboundmedicine.com/medline/citation/15731035/The_fimYZ_genes_regulate_Salmonella_enterica_Serovar_Typhimurium_invasion_in_addition_to_type_1_fimbrial_expression_and_bacterial_motility_ DB - PRIME DP - Unbound Medicine ER -