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hilA is a novel ompR/toxR family member that activates the expression of Salmonella typhimurium invasion genes.
Mol Microbiol. 1995 Nov; 18(4):715-27.MM

Abstract

During infection of its hosts, Salmonella enters intestinal epithelial cells. Many Salmonella typhimurium genes required for bacterial entry into host cells are encoded on a 40 kb 'pathogenicity island'. We report here the identification of hilA, a gene within the 'island' that appears to encode an activator of invasion gene expression. By using a set of lacZY transcriptional fusions to S. typhimurium invasion genes, we found that hilA activates the expression of invasion genes located on the 'pathogenicity island'. hilA is required for efficient entry into HEp-2 cells in vitro. The predicted amino acid sequence of hilA shares significant homology with the DNA-binding domains of the OmpR-ToxR family of transcriptional activators. However, unlike OmpR and ToxR, HilA contains neither a phosphoryl acceptor nor a membrane-spanning domain, and, therefore, its activity may be modulated by a novel mechanism. Many environmental conditions modulate the ability of Salmonella to enter non-phagocytic mammalian cells. It has been proposed that induction of Salmonella invasion proteins in response to a combination of environmental cues ensures that bacterial entry is limited to specific sites and times during infection. Our results are consistent with the hypothesis that hilA plays a key role in the regulation of Salmonella invasion during infection.

Authors+Show Affiliations

Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

8817493

Citation

Bajaj, V, et al. "HilA Is a Novel ompR/toxR Family Member That Activates the Expression of Salmonella Typhimurium Invasion Genes." Molecular Microbiology, vol. 18, no. 4, 1995, pp. 715-27.
Bajaj V, Hwang C, Lee CA. HilA is a novel ompR/toxR family member that activates the expression of Salmonella typhimurium invasion genes. Mol Microbiol. 1995;18(4):715-27.
Bajaj, V., Hwang, C., & Lee, C. A. (1995). HilA is a novel ompR/toxR family member that activates the expression of Salmonella typhimurium invasion genes. Molecular Microbiology, 18(4), 715-27.
Bajaj V, Hwang C, Lee CA. HilA Is a Novel ompR/toxR Family Member That Activates the Expression of Salmonella Typhimurium Invasion Genes. Mol Microbiol. 1995;18(4):715-27. PubMed PMID: 8817493.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - hilA is a novel ompR/toxR family member that activates the expression of Salmonella typhimurium invasion genes. AU - Bajaj,V, AU - Hwang,C, AU - Lee,C A, PY - 1995/11/1/pubmed PY - 1995/11/1/medline PY - 1995/11/1/entrez SP - 715 EP - 27 JF - Molecular microbiology JO - Mol Microbiol VL - 18 IS - 4 N2 - During infection of its hosts, Salmonella enters intestinal epithelial cells. Many Salmonella typhimurium genes required for bacterial entry into host cells are encoded on a 40 kb 'pathogenicity island'. We report here the identification of hilA, a gene within the 'island' that appears to encode an activator of invasion gene expression. By using a set of lacZY transcriptional fusions to S. typhimurium invasion genes, we found that hilA activates the expression of invasion genes located on the 'pathogenicity island'. hilA is required for efficient entry into HEp-2 cells in vitro. The predicted amino acid sequence of hilA shares significant homology with the DNA-binding domains of the OmpR-ToxR family of transcriptional activators. However, unlike OmpR and ToxR, HilA contains neither a phosphoryl acceptor nor a membrane-spanning domain, and, therefore, its activity may be modulated by a novel mechanism. Many environmental conditions modulate the ability of Salmonella to enter non-phagocytic mammalian cells. It has been proposed that induction of Salmonella invasion proteins in response to a combination of environmental cues ensures that bacterial entry is limited to specific sites and times during infection. Our results are consistent with the hypothesis that hilA plays a key role in the regulation of Salmonella invasion during infection. SN - 0950-382X UR - https://www.unboundmedicine.com/medline/citation/8817493/hilA_is_a_novel_ompR/toxR_family_member_that_activates_the_expression_of_Salmonella_typhimurium_invasion_genes_ DB - PRIME DP - Unbound Medicine ER -