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Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407

Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhea in children in developing countries, as well as in travelers to these countries. To cause disease, ETEC needs to produce a series of virulence proteins including enterotoxins, colonization factors and secretion pa...

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Autores principales: Hodson, Carla, Yang, Ji, Hocking, Dianna M., Azzopardi, Kristy, Chen, Qianyu, Holien, Jessica K., Parker, Michael W., Tauschek, Marija, Robins-Browne, Roy M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5554520/
https://www.ncbi.nlm.nih.gov/pubmed/28848532
http://dx.doi.org/10.3389/fmicb.2017.01525
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author Hodson, Carla
Yang, Ji
Hocking, Dianna M.
Azzopardi, Kristy
Chen, Qianyu
Holien, Jessica K.
Parker, Michael W.
Tauschek, Marija
Robins-Browne, Roy M.
author_facet Hodson, Carla
Yang, Ji
Hocking, Dianna M.
Azzopardi, Kristy
Chen, Qianyu
Holien, Jessica K.
Parker, Michael W.
Tauschek, Marija
Robins-Browne, Roy M.
author_sort Hodson, Carla
collection PubMed
description Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhea in children in developing countries, as well as in travelers to these countries. To cause disease, ETEC needs to produce a series of virulence proteins including enterotoxins, colonization factors and secretion pathways, which enable this pathogen to colonize the human small intestine and deliver enterotoxins to epithelial cells. Previously, a number of studies have demonstrated that CfaD, an AraC-like transcriptional regulator, plays a key role in virulence gene expression by ETEC. In this study, we carried out a transcriptomic analysis of ETEC strain, H10407, grown under different conditions, and determined the complete set of genes that are regulated by CfaD. In this way, we identified a number of new target genes, including rnr-1, rnr-2, etpBAC, agn43, flu, traM and ETEC_3214, whose expression is strongly activated by CfaD. Using promoter-lacZ reporters, primer extension and electrophoretic mobility shift assays, we characterized the CfaD-mediated activation of several selected target promoters. We also showed that the gut-associated environmental signal, sodium bicarbonate, stimulates CfaD-mediated upregulation of its virulence target operons. Finally, we screened a commercial small molecule library and identified a compound (CH-1) that specifically inhibited the regulatory function of CfaD, and by 2-D analoging, we identified a second inhibitor (CH-2) with greater potency.
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spelling pubmed-55545202017-08-28 Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407 Hodson, Carla Yang, Ji Hocking, Dianna M. Azzopardi, Kristy Chen, Qianyu Holien, Jessica K. Parker, Michael W. Tauschek, Marija Robins-Browne, Roy M. Front Microbiol Microbiology Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhea in children in developing countries, as well as in travelers to these countries. To cause disease, ETEC needs to produce a series of virulence proteins including enterotoxins, colonization factors and secretion pathways, which enable this pathogen to colonize the human small intestine and deliver enterotoxins to epithelial cells. Previously, a number of studies have demonstrated that CfaD, an AraC-like transcriptional regulator, plays a key role in virulence gene expression by ETEC. In this study, we carried out a transcriptomic analysis of ETEC strain, H10407, grown under different conditions, and determined the complete set of genes that are regulated by CfaD. In this way, we identified a number of new target genes, including rnr-1, rnr-2, etpBAC, agn43, flu, traM and ETEC_3214, whose expression is strongly activated by CfaD. Using promoter-lacZ reporters, primer extension and electrophoretic mobility shift assays, we characterized the CfaD-mediated activation of several selected target promoters. We also showed that the gut-associated environmental signal, sodium bicarbonate, stimulates CfaD-mediated upregulation of its virulence target operons. Finally, we screened a commercial small molecule library and identified a compound (CH-1) that specifically inhibited the regulatory function of CfaD, and by 2-D analoging, we identified a second inhibitor (CH-2) with greater potency. Frontiers Media S.A. 2017-08-11 /pmc/articles/PMC5554520/ /pubmed/28848532 http://dx.doi.org/10.3389/fmicb.2017.01525 Text en Copyright © 2017 Hodson, Yang, Hocking, Azzopardi, Chen, Holien, Parker, Tauschek and Robins-Browne. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Hodson, Carla
Yang, Ji
Hocking, Dianna M.
Azzopardi, Kristy
Chen, Qianyu
Holien, Jessica K.
Parker, Michael W.
Tauschek, Marija
Robins-Browne, Roy M.
Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title_full Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title_fullStr Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title_full_unstemmed Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title_short Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407
title_sort control of virulence gene expression by the master regulator, cfad, in the prototypical enterotoxigenic escherichia coli strain, h10407
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5554520/
https://www.ncbi.nlm.nih.gov/pubmed/28848532
http://dx.doi.org/10.3389/fmicb.2017.01525
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