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The CpxR/CpxA system contributes to Salmonella gold‐resistance by controlling the GolS‐dependent gesABC transcription
Author(s) -
Cerminati Sebastián,
Giri Germán F.,
Mendoza Julián I.,
Soncini Fernando C.,
Checa Susana K.
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13837
Subject(s) - biology , operon , transcription (linguistics) , transcription factor , lac operon , genetics , plasmid , gene , microbiology and biotechnology , escherichia coli , linguistics , philosophy
Summary Several regulatory systems contribute to bacterial resistance to heavy metals controlling the expression of factors required to eliminate the intoxicant and/or to repair the damage caused by it. In Salmonella , the response to Au ions is mediated by the specific metalloregulator GolS that, among other genes, controls the expression of the RND‐efflux pump GesABC. In this work, we demonstrate that CpxR/CpxA, a main cell‐envelope stress‐responding system, promotes gesABC transcription in the presence of Au ions at neutral pH. Deletion of either cpxA or cpxR , or mutation of the CpxR‐binding site identified upstream of the GolS‐operator in the gesABC promoter region reduces but does not abrogate the GolS‐ and Au‐dependent activation of gesABC . Au also triggers the activation of the CpxR/CpxA system and deletion of the cpxRA operon severely reduces survival in the presence of the toxic metal. Our results indicate that the coordinated action of GolS and CpxR/CpxA contribute to protecting the cell from severe Au damage.