Tags

Type your tag names separated by a space and hit enter

The Salmonella Spi1 virulence regulatory protein HilD directly activates transcription of the flagellar master operon flhDC.
J Bacteriol. 2014 Apr; 196(7):1448-57.JB

Abstract

Infection of intestinal epithelial cells is dependent on the Salmonella enterica serovar Typhimurium pathogenicity island 1 (Spi1)-encoded type III injectisome system and flagellar motility. Thus, the expression of virulence and flagellar genes is subject to tight regulatory control mechanisms in order to ensure the correct spatiotemporal production of the respective gene products. In this work, we reveal a new level of cross-regulation between the Spi1 and flagellar regulatory systems. Transposon mutagenesis identified a class of mutants that prevented flhDC autorepression by overexpressing HilD. HilD, HilC, RtsA, and HilA comprise a positive regulatory circuit for the expression of the Spi1 genes. Here, we report a novel transcriptional cross talk between the Spi1 and flagellar regulons where HilD transcriptionally activates flhDC gene expression by binding to nucleotides -68 to -24 upstream from the P5 transcriptional start site. We additionally show that, in contrast to the results of a previous report, HilA does not affect flagellar gene expression. Finally, we discuss a model of the cross-regulation network between Spi1 and the flagellar system and propose a regulatory mechanism via the Spi1 master regulator HilD that would prime flagellar genes for rapid reactivation during host infection.

Authors+Show Affiliations

Microbiologie, Département de Médecine, Université de Fribourg, Fribourg, Switzerland.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

24488311

Citation

Singer, Hanna M., et al. "The Salmonella Spi1 Virulence Regulatory Protein HilD Directly Activates Transcription of the Flagellar Master Operon FlhDC." Journal of Bacteriology, vol. 196, no. 7, 2014, pp. 1448-57.
Singer HM, Kühne C, Deditius JA, et al. The Salmonella Spi1 virulence regulatory protein HilD directly activates transcription of the flagellar master operon flhDC. J Bacteriol. 2014;196(7):1448-57.
Singer, H. M., Kühne, C., Deditius, J. A., Hughes, K. T., & Erhardt, M. (2014). The Salmonella Spi1 virulence regulatory protein HilD directly activates transcription of the flagellar master operon flhDC. Journal of Bacteriology, 196(7), 1448-57. https://doi.org/10.1128/JB.01438-13
Singer HM, et al. The Salmonella Spi1 Virulence Regulatory Protein HilD Directly Activates Transcription of the Flagellar Master Operon FlhDC. J Bacteriol. 2014;196(7):1448-57. PubMed PMID: 24488311.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The Salmonella Spi1 virulence regulatory protein HilD directly activates transcription of the flagellar master operon flhDC. AU - Singer,Hanna M, AU - Kühne,Caroline, AU - Deditius,Julia A, AU - Hughes,Kelly T, AU - Erhardt,Marc, Y1 - 2014/01/31/ PY - 2014/2/4/entrez PY - 2014/2/4/pubmed PY - 2014/5/16/medline SP - 1448 EP - 57 JF - Journal of bacteriology JO - J Bacteriol VL - 196 IS - 7 N2 - Infection of intestinal epithelial cells is dependent on the Salmonella enterica serovar Typhimurium pathogenicity island 1 (Spi1)-encoded type III injectisome system and flagellar motility. Thus, the expression of virulence and flagellar genes is subject to tight regulatory control mechanisms in order to ensure the correct spatiotemporal production of the respective gene products. In this work, we reveal a new level of cross-regulation between the Spi1 and flagellar regulatory systems. Transposon mutagenesis identified a class of mutants that prevented flhDC autorepression by overexpressing HilD. HilD, HilC, RtsA, and HilA comprise a positive regulatory circuit for the expression of the Spi1 genes. Here, we report a novel transcriptional cross talk between the Spi1 and flagellar regulons where HilD transcriptionally activates flhDC gene expression by binding to nucleotides -68 to -24 upstream from the P5 transcriptional start site. We additionally show that, in contrast to the results of a previous report, HilA does not affect flagellar gene expression. Finally, we discuss a model of the cross-regulation network between Spi1 and the flagellar system and propose a regulatory mechanism via the Spi1 master regulator HilD that would prime flagellar genes for rapid reactivation during host infection. SN - 1098-5530 UR - https://www.unboundmedicine.com/medline/citation/24488311/The_Salmonella_Spi1_virulence_regulatory_protein_HilD_directly_activates_transcription_of_the_flagellar_master_operon_flhDC_ DB - PRIME DP - Unbound Medicine ER -