Hypochlorous acid and hydrogen peroxide-induced negative regulation of Salmonella enterica serovar Typhimurium ompW by the response regulator ArcA

Eduardo H. Morales, Iván L. Calderán, Bernardo Collao, Fernando Gil, Steffen Porwollik, Michael McClelland, Claudia P. Saavedra

Resultado de la investigación: Article

22 Citas (Scopus)

Resumen

Background: Hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) are reactive oxygen species that are part of the oxidative burst encountered by Salmonella enterica serovar Typhimurium (S. Typhimurium) upon internalization by phagocytic cells. In order to survive, bacteria must sense these signals and modulate gene expression. Growing evidence indicates that the ArcAB two component system plays a role in the resistance to reactive oxygen species. We investigated the influx of H2O2 and HOCl through OmpW and the role of ArcAB in modulating its expression after exposure to both toxic compounds in S. Typhimurium. Results: H2O2 and HOCl influx was determined both in vitro and in vivo. A S. Typhimurium ompW mutant strain (δompW) exposed to sub-lethal levels of H2O 2 and HOCl showed a decreased influx of both compounds as compared to a wild type strain. Further evidence of H2O2 and HOCl diffusion through OmpW was obtained by using reconstituted proteoliposomes. We hypothesized that ompW expression should be negatively regulated upon exposure to H2O2 and HOCl to better exclude these compounds from the cell. As expected, qRT-PCR showed a negative regulation in a wild type strain treated with sub-lethal concentrations of these compounds. A bioinformatic analysis in search for potential negative regulators predicted the presence of three ArcA binding sites at the ompW promoter region. By electrophoretic mobility shift assay (EMSA) and using transcriptional fusions we demonstrated an interaction between ArcA and one site at the ompW promoter region. Moreover, qRT-PCR showed that the negative regulation observed in the wild type strain was lost in an arcA and in arcB mutant strains. Conclusions: OmpW allows the influx of H2O2 and HOCl and is negatively regulated by ArcA by direct interaction with the ompW promoter region upon exposure to both toxic compounds.

Idioma originalEnglish
Número de artículo63
PublicaciónBMC Microbiology
Volumen12
DOI
EstadoPublished - 2012

Huella dactilar

Hypochlorous Acid
Salmonella enterica
Hydrogen Peroxide
Genetic Promoter Regions
Poisons
Reactive Oxygen Species
Polymerase Chain Reaction
Respiratory Burst
Electrophoretic Mobility Shift Assay
Phagocytes
Serogroup
Computational Biology
Binding Sites
Bacteria
Gene Expression

ASJC Scopus subject areas

  • Microbiology
  • Microbiology (medical)

Citar esto

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title = "Hypochlorous acid and hydrogen peroxide-induced negative regulation of Salmonella enterica serovar Typhimurium ompW by the response regulator ArcA",
abstract = "Background: Hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) are reactive oxygen species that are part of the oxidative burst encountered by Salmonella enterica serovar Typhimurium (S. Typhimurium) upon internalization by phagocytic cells. In order to survive, bacteria must sense these signals and modulate gene expression. Growing evidence indicates that the ArcAB two component system plays a role in the resistance to reactive oxygen species. We investigated the influx of H2O2 and HOCl through OmpW and the role of ArcAB in modulating its expression after exposure to both toxic compounds in S. Typhimurium. Results: H2O2 and HOCl influx was determined both in vitro and in vivo. A S. Typhimurium ompW mutant strain (δompW) exposed to sub-lethal levels of H2O 2 and HOCl showed a decreased influx of both compounds as compared to a wild type strain. Further evidence of H2O2 and HOCl diffusion through OmpW was obtained by using reconstituted proteoliposomes. We hypothesized that ompW expression should be negatively regulated upon exposure to H2O2 and HOCl to better exclude these compounds from the cell. As expected, qRT-PCR showed a negative regulation in a wild type strain treated with sub-lethal concentrations of these compounds. A bioinformatic analysis in search for potential negative regulators predicted the presence of three ArcA binding sites at the ompW promoter region. By electrophoretic mobility shift assay (EMSA) and using transcriptional fusions we demonstrated an interaction between ArcA and one site at the ompW promoter region. Moreover, qRT-PCR showed that the negative regulation observed in the wild type strain was lost in an arcA and in arcB mutant strains. Conclusions: OmpW allows the influx of H2O2 and HOCl and is negatively regulated by ArcA by direct interaction with the ompW promoter region upon exposure to both toxic compounds.",
author = "Morales, {Eduardo H.} and Calder{\'a}n, {Iv{\'a}n L.} and Bernardo Collao and Fernando Gil and Steffen Porwollik and Michael McClelland and Saavedra, {Claudia P.}",
year = "2012",
doi = "10.1186/1471-2180-12-63",
language = "English",
volume = "12",
journal = "BMC Microbiology",
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Hypochlorous acid and hydrogen peroxide-induced negative regulation of Salmonella enterica serovar Typhimurium ompW by the response regulator ArcA. / Morales, Eduardo H.; Calderán, Iván L.; Collao, Bernardo; Gil, Fernando; Porwollik, Steffen; McClelland, Michael; Saavedra, Claudia P.

En: BMC Microbiology, Vol. 12, 63, 2012.

Resultado de la investigación: Article

TY - JOUR

T1 - Hypochlorous acid and hydrogen peroxide-induced negative regulation of Salmonella enterica serovar Typhimurium ompW by the response regulator ArcA

AU - Morales, Eduardo H.

AU - Calderán, Iván L.

AU - Collao, Bernardo

AU - Gil, Fernando

AU - Porwollik, Steffen

AU - McClelland, Michael

AU - Saavedra, Claudia P.

PY - 2012

Y1 - 2012

N2 - Background: Hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) are reactive oxygen species that are part of the oxidative burst encountered by Salmonella enterica serovar Typhimurium (S. Typhimurium) upon internalization by phagocytic cells. In order to survive, bacteria must sense these signals and modulate gene expression. Growing evidence indicates that the ArcAB two component system plays a role in the resistance to reactive oxygen species. We investigated the influx of H2O2 and HOCl through OmpW and the role of ArcAB in modulating its expression after exposure to both toxic compounds in S. Typhimurium. Results: H2O2 and HOCl influx was determined both in vitro and in vivo. A S. Typhimurium ompW mutant strain (δompW) exposed to sub-lethal levels of H2O 2 and HOCl showed a decreased influx of both compounds as compared to a wild type strain. Further evidence of H2O2 and HOCl diffusion through OmpW was obtained by using reconstituted proteoliposomes. We hypothesized that ompW expression should be negatively regulated upon exposure to H2O2 and HOCl to better exclude these compounds from the cell. As expected, qRT-PCR showed a negative regulation in a wild type strain treated with sub-lethal concentrations of these compounds. A bioinformatic analysis in search for potential negative regulators predicted the presence of three ArcA binding sites at the ompW promoter region. By electrophoretic mobility shift assay (EMSA) and using transcriptional fusions we demonstrated an interaction between ArcA and one site at the ompW promoter region. Moreover, qRT-PCR showed that the negative regulation observed in the wild type strain was lost in an arcA and in arcB mutant strains. Conclusions: OmpW allows the influx of H2O2 and HOCl and is negatively regulated by ArcA by direct interaction with the ompW promoter region upon exposure to both toxic compounds.

AB - Background: Hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) are reactive oxygen species that are part of the oxidative burst encountered by Salmonella enterica serovar Typhimurium (S. Typhimurium) upon internalization by phagocytic cells. In order to survive, bacteria must sense these signals and modulate gene expression. Growing evidence indicates that the ArcAB two component system plays a role in the resistance to reactive oxygen species. We investigated the influx of H2O2 and HOCl through OmpW and the role of ArcAB in modulating its expression after exposure to both toxic compounds in S. Typhimurium. Results: H2O2 and HOCl influx was determined both in vitro and in vivo. A S. Typhimurium ompW mutant strain (δompW) exposed to sub-lethal levels of H2O 2 and HOCl showed a decreased influx of both compounds as compared to a wild type strain. Further evidence of H2O2 and HOCl diffusion through OmpW was obtained by using reconstituted proteoliposomes. We hypothesized that ompW expression should be negatively regulated upon exposure to H2O2 and HOCl to better exclude these compounds from the cell. As expected, qRT-PCR showed a negative regulation in a wild type strain treated with sub-lethal concentrations of these compounds. A bioinformatic analysis in search for potential negative regulators predicted the presence of three ArcA binding sites at the ompW promoter region. By electrophoretic mobility shift assay (EMSA) and using transcriptional fusions we demonstrated an interaction between ArcA and one site at the ompW promoter region. Moreover, qRT-PCR showed that the negative regulation observed in the wild type strain was lost in an arcA and in arcB mutant strains. Conclusions: OmpW allows the influx of H2O2 and HOCl and is negatively regulated by ArcA by direct interaction with the ompW promoter region upon exposure to both toxic compounds.

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U2 - 10.1186/1471-2180-12-63

DO - 10.1186/1471-2180-12-63

M3 - Article

C2 - 22545862

AN - SCOPUS:84861362033

VL - 12

JO - BMC Microbiology

JF - BMC Microbiology

SN - 1471-2180

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ER -