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Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA.
Microbiology (Reading). 2011 Sep; 157(Pt 9):2504-2514.M

Abstract

Coordination of the expression of Salmonella enterica invasion genes on Salmonella pathogenicity island 1 (SPI1) depends on a complex circuit involving several regulators that converge on expression of the hilA gene, which encodes a transcriptional activator (HilA) that modulates expression of the SPI1 virulence genes. Two of the global regulators that influence hilA expression are the nucleoid-associated proteins Hha and H-NS. They interact and form a complex that modulates gene expression. A chromosomal transcriptional fusion was constructed to assess the effects of these modulators on hilA transcription under several environmental conditions as well as at different stages of growth. The results obtained showed that these proteins play a role in silencing hilA expression at both low temperature and low osmolarity, irrespective of the growth phase. H-NS accounts for the main repressor activity. At high temperature and osmolarity, H-NS-mediated silencing completely ceases when cells enter the stationary phase, and hilA expression is induced. Mutants lacking IHF did not induce hilA in cells entering the stationary phase, and this lack of induction was dependent on the presence of H-NS. Band-shift assays and in vitro transcription data showed that for hilA induction under certain growth conditions, IHF is required to alleviate H-NS-mediated silencing.

Authors+Show Affiliations

Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain.Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain.Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain.Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain.Institut de Bioenginyeria de Catalunya (IBEC), Parc Científic de Barcelona, Baldiri Reixach, 15-21, 08028 Barcelona, Spain. Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal, 645, 08028 Barcelona, Spain.

Pub Type(s)

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

Language

eng

PubMed ID

21680637

Citation

Queiroz, Mário H., et al. "Integration Host Factor Alleviates H-NS Silencing of the Salmonella Enterica Serovar Typhimurium Master Regulator of SPI1, HilA." Microbiology (Reading, England), vol. 157, no. Pt 9, 2011, pp. 2504-2514.
Queiroz MH, Madrid C, Paytubi S, et al. Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA. Microbiology (Reading). 2011;157(Pt 9):2504-2514.
Queiroz, M. H., Madrid, C., Paytubi, S., Balsalobre, C., & Juárez, A. (2011). Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA. Microbiology (Reading, England), 157(Pt 9), 2504-2514. https://doi.org/10.1099/mic.0.049197-0
Queiroz MH, et al. Integration Host Factor Alleviates H-NS Silencing of the Salmonella Enterica Serovar Typhimurium Master Regulator of SPI1, HilA. Microbiology (Reading). 2011;157(Pt 9):2504-2514. PubMed PMID: 21680637.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA. AU - Queiroz,Mário H, AU - Madrid,Cristina, AU - Paytubi,Sònia, AU - Balsalobre,Carlos, AU - Juárez,Antonio, Y1 - 2011/06/16/ PY - 2011/6/18/entrez PY - 2011/6/18/pubmed PY - 2012/1/12/medline SP - 2504 EP - 2514 JF - Microbiology (Reading, England) JO - Microbiology (Reading) VL - 157 IS - Pt 9 N2 - Coordination of the expression of Salmonella enterica invasion genes on Salmonella pathogenicity island 1 (SPI1) depends on a complex circuit involving several regulators that converge on expression of the hilA gene, which encodes a transcriptional activator (HilA) that modulates expression of the SPI1 virulence genes. Two of the global regulators that influence hilA expression are the nucleoid-associated proteins Hha and H-NS. They interact and form a complex that modulates gene expression. A chromosomal transcriptional fusion was constructed to assess the effects of these modulators on hilA transcription under several environmental conditions as well as at different stages of growth. The results obtained showed that these proteins play a role in silencing hilA expression at both low temperature and low osmolarity, irrespective of the growth phase. H-NS accounts for the main repressor activity. At high temperature and osmolarity, H-NS-mediated silencing completely ceases when cells enter the stationary phase, and hilA expression is induced. Mutants lacking IHF did not induce hilA in cells entering the stationary phase, and this lack of induction was dependent on the presence of H-NS. Band-shift assays and in vitro transcription data showed that for hilA induction under certain growth conditions, IHF is required to alleviate H-NS-mediated silencing. SN - 1465-2080 UR - https://www.unboundmedicine.com/medline/citation/21680637/Integration_host_factor_alleviates_H_NS_silencing_of_the_Salmonella_enterica_serovar_Typhimurium_master_regulator_of_SPI1_hilA_ L2 - http://mic.microbiologyresearch.org/pubmed/content/journal/micro/10.1099/mic.0.049197-0 DB - PRIME DP - Unbound Medicine ER -