A TetR-family regulator of an RND efflux system that directs artemisinin resistance in Vibrio cholerae
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ABSTRACT:
PROVIDER: PRJNA1027081 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR26360115_1.fastq.gz | Fastqsanger.gz | |||
| SRR26360115_2.fastq.gz | Fastqsanger.gz | |||
| SRR26360116_1.fastq.gz | Fastqsanger.gz | |||
| SRR26360116_2.fastq.gz | Fastqsanger.gz | |||
| SRR26360117_1.fastq.gz | Fastqsanger.gz |
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Project description:Artemisinin (ARS) displayed bactericidal activity against Vibrio cholerae. To assess the mechanistic details of its antibacterial action, we have isolated V. cholerae mutants with enhanced ARS resistance and identified a gene (VCA0767), whose loss-of-function resulted in the ARS resistance phenotypes. This gene (atrR) encodes a TetR family transcriptional regulator, and its deletion mutant displayed the reduction in ARS-induced ROS formation and DNA damage. Transcriptomic analysis revealed that the genes encoding an RND efflux pump operon (vexRAB) and the outer membrane component (tolC) were highly upregulated in the artR mutant, suggesting that AtrR might act as a negative regulator of this operon and tolC. Gene deletion of vexR, vexB or tolC abrogated the ARS resistance of the atrR mutant and, more importantly, the ectopic expression of VexAB-TolC was sufficient for the ARS resistance, indicating that the increased expression of the VexAB-TolC efflux system is necessary and sufficient for the ARS resistance of the atrR mutant. The cytoplasmic accumulation of ARS was compromised in the vexBtolC mutant, suggesting that the VexAB-TolC might be the primary efflux system exporting ARS to reduce its toxicity inside of the bacterial cells. The atrR mutant displayed resistance to erythromycin as well in a VexR-dependent manner. This result suggests that AtrR may act as a global regulator responsible for preventing intracellular accumulation of toxic chemicals by enhancing the RND efflux system.
2023-10-16 | GSE245142 | GEO
Project description:Pseudomonas aeruginosa is an opportunistic human pathogen, which is ubiquitous in the environment. The environmental versatility of P. aeruginosa is often attributed to a large arsenal of active efflux pumps, low permeability of the outer membrane and extensive regulatory networks. In this study, we analyzed putative functional interplay between polyspecific drug efflux pumps of Resistance-Nodulation-Division (RND) superfamily of proteins and GacSA two-component regulatory system. RND transporters are the major contributors to antibiotic resistance and survival under various environmental stresses, whereas GacSA is a global regulator and governs critical lifestyles during human colonization. We found that the inactivation of either RND pumps or gacS induces broad, partially overlapping responses in lifestyle, virulence and metabolic programs that are more pronounced during exponential than stationary phase. GacSA and RND efflux pumps induced opposite responses in gene expression of P. aeruginosa, whereas the overexpression of GacS was additive with the deletion of efflux pumps in gene expression and under growth conditions typically associated with human infections such as elevated temperature and iron deprivation. We conclude that RND efflux and GacSA networks partially overlap with each other.
2025-03-01 | GSE284138 | GEO
Project description:To compare the expression profile of B. cenocepacia mutants impaired in RND efflux pump encoding genes
2011-04-23 | E-MEXP-2999 | biostudies-arrayexpress
Project description:Artemisinin (ARS) displayed bactericidal activity against Vibrio cholerae. To assess the mechanistic details of its antibacterial action, we have isolated V. cholerae mutants with enhanced ARS resistance and identified a gene (VCA0767) whose loss-of-function resulted in the ARS resistance phenotypes. This gene (atrR) encodes a TetR family transcriptional regulator, and its deletion mutant displayed the reduction in ARS-induced ROS formation and DNA damage. Transcriptomic analysis revealed that the genes encoding a resistance-nodulation-cell division (RND) efflux pump operon (vexRAB) and the outer membrane component (tolC) were highly upregulated in the artR mutant, suggesting that AtrR might act as a negative regulator of this operon and tolC. Gene deletion of vexR, vexB, or tolC abrogated the ARS resistance of the atrR mutant, and more importantly, the ectopic expression of VexAB-TolC was sufficient for the ARS resistance, indicating that the increased expression of the VexAB-TolC efflux system is necessary and sufficient for the ARS resistance of the atrR mutant. The cytoplasmic accumulation of ARS was compromised in the vexBtolC mutant, suggesting that the VexAB-TolC might be the primary efflux system exporting ARS to reduce its toxicity inside of the bacterial cells. The atrR mutant displayed resistance to erythromycin as well in a VexR-dependent manner. This result suggests that AtrR may act as a global regulator responsible for preventing intracellular accumulation of toxic chemicals by enhancing the RND efflux system.IMPORTANCEDrug efflux protein complexes or efflux pumps are considered as the major determinants of multiple antimicrobial resistance by exporting a wide range of structurally diverse antibiotics in bacterial pathogens. Despite the clinical significance of the increased expression of the efflux pumps, their substrate specificity and regulation mechanisms are poorly understood. Here, we demonstrated that VexAB-TolC, a resistance-nodulation-cell division (RND) efflux pump of V. cholerae, is responsible for the resistance to artemisinin (ARS), an antimalarial drug with bactericidal activity. Furthermore, we newly identified AtrR, a TetR family repressor, as a global regulator for VexRAB and the common outer membrane channel, TolC, where VexR functions as the pathway-specific regulator of the vexAB operon. Our findings will help improve our insight into a broad range of substrate specificity of the VexAB-TolC system and highlight the complex regulatory networks of the multiple RND efflux systems during V. cholerae pathogenesis.
| S-EPMC10805010 | biostudies-literature
Project description:To compare the expression profile of B. cenocepacia mutants impaired in RND efflux pump encoding genes
2011-04-23 | E-MEXP-2997 | biostudies-arrayexpress
Project description:Purpose: In this study, we analyzed how P. aeruginosa physiology is adapted to the lack of RND-mediated efflux activities. Methods: In this study, we use PΔ6 cells to analyze how P. aeruginosa changes its physiology in response to the lack of efflux pumps and increased permeability of the cell envelope. We compared the transcriptomes of the exponentially growing and stationary PΔ6 and its parent PAO1 cells and identified the cellular functions stressed by the lack of active efflux. High quality total RNA was further processed by removing 23S and 16S rRNAs using the Illumina Ribo-Zero Plus rRNA Depletion kit. Samples were analyzed in duplicate using Illumina MiSeq. Raw data for each sample was analyzed using CLC Genomics Workbench version 12.0.1 software (QIAGEN Aarhus, Denmark). Results: P. aeruginosa PΔ6 strain lacking six best characterized RND pumps activates a specific adaptation response that involves significant changes in expression of specific subset of genes encoding e.g. several transport systems, quorum sensing or iron acquisition. Conclusion: Our results suggest that all changes we observe serve to protect the cell envelope of efflux-deficient P. aeruginosa.
2021-04-30 | GSE169036 | GEO
Project description:Efflux pumps of the resistance-nodulation-division (RND) superfamily, particularly the AcrAB-TolC and MexAB-OprM, besides mediating intrinsic and acquired resistance, also intervene in bacterial pathogenicity. Inhibitors of such pumps could restore activities of antibiotics and curb bacterial virulence. Here, we identify pyrrole-based compounds that boost antibiotic activity in Escherichia coli and Pseudomonas aeruginosa by inhibiting their archetype RND transporters. The discovered efflux pump inhibitors (EPIs) inhibit the efflux of fluorescent probes, attenuate persister formation, and diminish resistant mutant development. Molecular docking and biophysical studies revealed that the EPIs bind to AcrB. EPIs also possess an anti-pathogenic potential and attenuate P. aeruginosa virulence in vivo. The excellent efficacy of the EPI-antibiotic combination was evidenced in animal lung infection and sepsis protection models. These findings indicate that EPIs discovered herein with no off-target effects and negligible toxicity are potential antibiotic adjuvants to address life-threatening bacterial infections.
2024-03-18 | GSE210309 | GEO
Project description:Functional interplay between RND efflux pumps and GacS in Pseudomonas aeruginosa
| PRJNA1197429 | ENA
Project description:Physiology of Pseudomonas aeruginosa cells without major RND-type multidrug efflux pumps
| PRJNA714944 | ENA
Project description:Mycobacterium tuberculosis has the ability to survive inside macrophages under acid-nitrosative stress. M. tuberculosis Rv1685c and its orthologue in M. smegmatis, MSMEG_3765, are induced on exposure to acid-nitrosative stress. Both genes are annotated as TetR transcriptional regulators, a family of proteins that regulate a wide range of cellular activities, including multidrug resistance, carbon catabolism and virulence. Here we demonstrate that MSMEG_3765 is co-transcribed with the upstream genes MSMEG_3762 and MSMEG_3763, encoding efflux pump components. RTq-PCR and GFP-reporter assays showed that the MSMEG_3762/63/65 gene cluster, and the orthologous region in M. tuberculosis (Rv1687c/86c/85c), was up-regulated in a MSMEG_3765 null mutant, suggesting that MSMEG_3765 acts as a repressor, typical of this family of regulators. We further defined the MSMEG_3765 regulon using genome-wide transcriptional profiling and confirmed that the MSMEG_3762/63/65 promoter is induced under acid-nitrosative stress. A putative 36 bp regulatory motif was identified upstream of the gene clusters in both M. smegmatis and M. tuberculosis and purified recombinant MSMEG_3765 protein was found to bind to DNA fragments containing this motif from both M. smegmatis and M. tuberculosis upstream regulatory regions. These results suggest that the TetR repressor MSMEG_3765/Rv1685c controls expression of an efflux pump with an, as yet, undefined role in the mycobacterial response to acid-nitrosative stress.
2017-10-24 | E-MTAB-5869 | biostudies-arrayexpress