The CpxR/CpxA system contributes to <i>Salmonella</i> gold‐resistance by controlling the GolS‐dependent <i>gesABC</i> transcription

Cerminati, Sebastián; Giri, German Francisco; Mendoza, Julián I.; Soncini, Fernando C.; Checa, Susana K.

doi:10.1111/1462-2920.13837

Cited by 14 publications

(13 citation statements)

References 47 publications

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“…This relationship was confirmed by cpxRA knockouts that demonstrated heightened gold sensitivity compared to the wild-type after Au exposure. These results support interaction between metal resistance and general stress response systems in bacteria (Cerminati et al 2017). In E. coli, it has been shown that CueR, the transcriptional regulator of the cue operon that activates the promoter of CopA, is triggered by gold salts through cysteine residues that can recognize gold, silver, and copper.…”

Section: Goldsupporting

confidence: 68%

Biological links between nanoparticle biosynthesis and stress responses in bacteria

2018

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There is rising interest in nanoparticle biosynthesis using bacteria due to the potential for applications in bioremediation, catalysis, or as antimicrobials. However, biosynthesis remains limited by the inability to control nanoparticle morphology and size due to the lack of knowledge regarding explicit molecular mechanisms. Due to their importance in nanoparticle biosynthesis and as antimicrobials, we focus our discussion on silver, gold, and copper nanoparticles. We discuss recent efforts to elucidate reduction mechanisms that have identified generic enzymes and metal resistance genes as strong candidates to facilitate nanoparticle biosynthesis. Although it is known that these enzymes and genes play significant roles in maintaining bacterial homeostasis, there are few reports discussing this topic. Thus, we discuss examples of how metal resistance genes are conserved across bacteria and have been shown to be important for both nanoparticle biosynthesis and processes such as virulence or oxidative stress responses. Overall, this review highlights biological connections between nanoparticle biosynthesis and stress responses by examining the role of reductases and metal resistance genes in both processes. This understanding provides a greater role for nanoparticle biosynthesis in bacteria and could enable a systems biology level of control over nanoparticle biosynthesis.

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Section: Goldsupporting

confidence: 68%

Biological links between nanoparticle biosynthesis and stress responses in bacteria

2018

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“…We also showed that Cu induction of scsABCD depended on CpxR/CpxA (Fig. 1, 2, and 3), a two-component system essential for preserving and/or repairing periplasmic or inner membrane proteins damaged by different physical or chemical agents, including metals such as Cu, Zn, and Au (36,37,45). Our results indicate that, like scsA transcription, transcription of scsB, scsC, and scsD is driven by the CpxR-dependent scsA promoter, at least during copper stress.…”

Section: Discussionmentioning

confidence: 74%

“…Protein-DNA interaction assays. EMSAs and DNase I footprinting assays were performed using 6 fmol of a 32 P-labeled DNA fragment containing the scsABCD promoter and CpxR-P, basically as described previously (16,45). CpxR-P was obtained by incubating purified His-tagged CpxR with 25 mM acetyl phosphate for 1 h at 30°C.…”

Section: Methodsmentioning

confidence: 99%

CpxR/CpxA ControlsscsABCDTranscription To Counteract Copper and Oxidative Stress in Salmonella enterica Serovar Typhimurium

2018

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Periplasmic thiol/disulfide oxidoreductases participate in the formation and isomerization of disulfide bonds and contribute to the virulence of pathogenic microorganisms. Among the systems encoded in the genome, the system encoded by the locus was shown to be required to cope with Cu and HO stress. Here we report that this locus forms an operon whose transcription is driven by a promoter upstream of and depends on CpxR/CpxA and on Cu. Furthermore, genes homologous to, , and are always detected immediately downstream of and in the same genetic arrangement in all-harboring enterobacterial species. Also, a CpxR-binding site is detected upstream of in most of those species, providing evidence of evolutionarily conserved function and regulation. Each individual gene shows a different role in copper and/or HO resistance, indicating hierarchical contributions of these factors in the defense against these intoxicants. A protective effect of Cu preincubation against HO toxicity and the increased Cu-mediated activation of in the Δ mutant suggest that the CpxR/CpxA-controlled transcription of the ScsABCD system contributes to prevent Cu toxicity and to restore the redox balance at the envelope. Copper intoxication triggers both specific and nonspecific responses in The locus, which codes for periplasmic thiol/disulfide-oxidoreductase/isomerase-like proteins, has been the focus of attention because it is necessary for copper resistance, oxidative stress responses, and virulence and because it is not present in nonpathogenic Still, the conditions under which the locus is expressed and the roles of its individual components remain unknown. In this report, we examine the contribution of each Scs factor to survival under HO and copper stress. We establish that the genes form a copper-activated operon controlled by the CpxR/CpxA signal transduction system, and we provide evidence of its conserved gene arrangement and regulation in other bacterial pathogens.

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“…Prediction of CpxR-binding site. The consensus motif for the CpxR-binding site was generated by training the Multiple Expectation Maximization for motif Elicitation (MEME) tool (46) using as input cognate binding sequences in the promoter regions of the following CpxR-regulated genes from Salmonella: cpxP1, cpxP2, htrA, ppiA, yccA, spy, dsbA, amiA, amiC, cueP, gesA, and scsA (71)(72)(73)(74)(75). The obtained matrix was then submitted to the Find Individual Motif Occurrences (FIMO) tool to detect the presence of the motif in the promoter region of the prtA gene from S. marcescens (47).…”

Section: Methodsmentioning

confidence: 99%

CpxR-Dependent Thermoregulation of Serratia marcescens PrtA Metalloprotease Expression and Its Contribution to Bacterial Biofilm Formation

et al. 2018

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PrtA is the major secreted metalloprotease of Previous reports implicate PrtA in the pathogenic capacity of this bacterium. PrtA is also clinically used as a potent analgesic and anti-inflammatory drug, and its catalytic properties attract industrial interest. Comparatively, there is scarce knowledge about the mechanisms that physiologically govern PrtA expression in In this work, we demonstrate that PrtA production is derepressed when the bacterial growth temperature decreases from 37°C to 30°C. We show that this thermoregulation occurs at the transcriptional level. We determined that upstream of , there is a conserved motif that is directly recognized by the CpxR transcriptional regulator. This feature is found along strains irrespective of their isolation source, suggesting an evolutionary conservation of CpxR-dependent regulation of PrtA expression. We found that in s, the CpxAR system is more active at 37°C than at 30°C. In good agreement with these results, in a mutant background, is derepressed at 37°C, while overexpression of the NlpE lipoprotein, a well-known CpxAR-inducing condition, inhibits PrtA expression, suggesting that the levels of the activated form of CpxR are increased at 37°C over those at 30°C. In addition, we establish that PrtA is involved in the ability of to develop biofilm. In accordance, CpxR influences the biofilm phenotype only when bacteria are grown at 37°C. In sum, our findings shed light on regulatory mechanisms that fine-tune PrtA expression and reveal a novel role for PrtA in the lifestyle of We demonstrate that metalloprotease PrtA expression is transcriptionally thermoregulated. While strongly activated below 30°C, its expression is downregulated at 37°C. We found that in , the CpxAR signal transduction system, which responds to envelope stress and bacterial surface adhesion, is activated at 37°C and able to downregulate PrtA expression by direct interaction of CpxR with a binding motif located upstream of the gene. Moreover, we reveal that PrtA expression favors the ability of to develop biofilm, irrespective of the bacterial growth temperature. In this context, thermoregulation along with a highly conserved CpxR-dependent modulation mechanism gives clues about the relevance of PrtA as a factor implicated in the persistence of on abiotic surfaces and in bacterial host colonization capacity.

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The CpxR/CpxA system contributes to Salmonella gold‐resistance by controlling the GolS‐dependent gesABC transcription

Cited by 14 publications

References 47 publications

Biological links between nanoparticle biosynthesis and stress responses in bacteria

Biological links between nanoparticle biosynthesis and stress responses in bacteria

CpxR/CpxA ControlsscsABCDTranscription To Counteract Copper and Oxidative Stress in Salmonella enterica Serovar Typhimurium

CpxR-Dependent Thermoregulation of Serratia marcescens PrtA Metalloprotease Expression and Its Contribution to Bacterial Biofilm Formation

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