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The ActP acetate transporter acts prior to the PitA phosphate carrier in tellurite uptake by Escherichia coli.
Elías, Alex; Díaz-Vásquez, Waldo; Abarca-Lagunas, María José; Chasteen, Thomas G; Arenas, Felipe; Vásquez, Claudio C.
Afiliação
  • Elías A; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile; Facultad de Ciencias de la Salud, Universidad San Sebastián, Santiago, Chile.
  • Díaz-Vásquez W; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile; Facultad de Ciencias de la Salud, Universidad San Sebastián, Santiago, Chile.
  • Abarca-Lagunas MJ; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
  • Chasteen TG; Department of Chemistry and Texas Research Institute for Environmental Studies, Sam Houston State University, Huntsville, TX, USA.
  • Arenas F; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
  • Vásquez CC; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile. Electronic address: claudio.vasquez@usach.cl.
Microbiol Res ; 177: 15-21, 2015 Aug.
Article em En | MEDLINE | ID: mdl-26211961
The tellurium oxyanion tellurite is harmful for most microorganisms. Since its toxicity occurs chiefly once the toxicant reaches the intracellular compartment, unveiling the toxicant uptake process is crucial for understanding the whole phenomenon of tellurium toxicity. While the PitA phosphate transporter is thought to be one of the main paths responsible for toxicant entry into Escherichia coli, genetic and physiological evidence have identified the ActP acetate carrier as the main tellurite importer in Rhodobacter capsulatus. In this work, new background on the role of these transporters in tellurite uptake by E. coli is presented. It was found that, similar to what occurs in R. capsulatus, ActP is able to mediate toxicant entry to this bacterium. Lower reactive oxygen species levels were observed in E. coli lacking the actP gene. Antioxidant enzyme catalase and fumarase C activity was almost unchanged after short exposure of E. coli ΔactP to sublethal tellurite concentrations, suggesting a low antioxidant response. In this strain, tellurite uptake decreased significantly during the first 5 min of exposure and inductively coupled plasma optical emission spectroscopy assays using an actP-overexpressing strain confirmed that this carrier mediates toxicant uptake. Relative gene expression experiments by qPCR showed that actP expression is enhanced at short times of tellurite exposure, while pitA and pitB genes are induced later. Summarizing, the results show that ActP is involved in tellurite entry to E. coli and that its participation occurs mainly at early stages of toxicant exposure.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Telúrio / Proteínas de Escherichia coli / Transportadores de Ácidos Monocarboxílicos / Proteínas de Transporte de Fosfato / Escherichia coli Idioma: En Revista: Microbiol Res Assunto da revista: MICROBIOLOGIA / SAUDE AMBIENTAL Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Chile País de publicação: Alemanha
Texto completo
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Imprimir
XML
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Telúrio / Proteínas de Escherichia coli / Transportadores de Ácidos Monocarboxílicos / Proteínas de Transporte de Fosfato / Escherichia coli Idioma: En Revista: Microbiol Res Assunto da revista: MICROBIOLOGIA / SAUDE AMBIENTAL Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Chile País de publicação: Alemanha