PutA Is Required for Virulence and Regulated by PruR in Pseudomonas aeruginosa

Zheng, Ruiping; Feng, Xiao; Wei, Xueying; Pan, Xiaolei; Liu, Chang; Song, Ruopu; Jin, Yongxin; Bai, Fang; Jin, Shouguang; Wu, Weihui; Cheng, Zhihui

doi:10.3389/fmicb.2018.00548

Cited by 11 publications

(10 citation statements)

References 65 publications

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“…Electrophoretic mobility shift assay (EMSA) was performed as described with modification [ 23 ]. DNA probes were amplified using specific primers (Table S1).…”

Section: Methodsmentioning

confidence: 99%

Insights into the mechanism regulating the differential expression of the P28-OMP outer membrane proteins in obligatory intracellular pathogen Ehrlichia chaffeensis

Duan

Cui

et al. 2021

Emerging Microbes & Infections

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Ehrlichia chaffeensis causes human monocytic ehrlichiosis (HME), which is one of the most prevalent, life-threatening emerging infectious zoonoses. The life cycle of E. chaffeensis includes ticks and mammals, in which E. chaffeensis proteins are expressed differentially contributing to bacterial survival and infection. Among the E. chaffeensis P28-OMP outer membrane proteins, OMP-1B and P28 are predominantly expressed in tick cells and mammalian macrophages, respectively. The mechanisms regulating this differential expression have not been comprehensively studied. Here, we demonstrate that the transcriptional regulators EcxR and Tr1 regulate the differential expression of omp-1B and p28 in E. chaffeensis. Recombinant E. chaffeensis Tr1 bound to the promoters of omp-1B and p28, and transactivated omp-1B and p28 promoter-EGFP fusion constructs in Escherichia coli . The consensus sequence of Tr1 binding motifs was A C / T TATA as determined with DNase I footprint assay. Tr1 showed a higher affinity towards the p28 promoter than the omp-1B promoter as determined with surface plasmon resonance. EcxR activated the tr1 expression in response to a temperature decrease. At 37°C low level of Tr1 activated the p28 expression. At 25°C high level of Tr1 activated the omp-1B expression, while repressing the p28 expression by binding to an additional site upstream of the p28 gene. Our data provide insights into a novel mechanism mediated by Tr1 regulating E. chaffeensis differential gene expression, which may aid in the development of new therapeutics for HME.

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“…Electrophoretic mobility shift assay (EMSA) was performed as described with modification [ 23 ]. DNA probes were amplified using specific primers (Table S1).…”

Section: Methodsmentioning

confidence: 99%

Insights into the mechanism regulating the differential expression of the P28-OMP outer membrane proteins in obligatory intracellular pathogen Ehrlichia chaffeensis

Duan

Cui

et al. 2021

Emerging Microbes & Infections

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“…putA , predicted to encode 1-pyrroline-5-carboxylate dehydrogenase, an enzyme involved in the conversion of proline to glutamate, was negatively regulated (2<|fold change|) in the ΔlrhA and ΔrpoS strains, and positively regulated in the secondary form strain. PutA is necessary for virulence in Pseudomonas aeruginosa and protects the bacterium against oxidative stress {Zheng, 2018}. XNC1_2468 is downregulated in the Δ lrp , Δ rpoS , and secondary form mutant backgrounds.…”

Section: Resultsmentioning

confidence: 99%

Chemical ecology of an apex predator life cycle

Jones

Cao

et al. 2021

Preprint

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Microbial symbiotic interactions, mediated in part by small molecule signaling, drive physiological processes of higher order systems, including the acquisition and consumption of nutrients that support symbiotic partner reproduction. Advances in metabolic analytic technologies provide new avenues to examine how chemical ecology, or the conversion of existing biomass to new forms, changes over a symbiotic lifecycle. Here we examine such processes using the tripartite relationship involving the nematode host Steinernema carpocapsae, its obligate mutualist bacterium, Xenorhabdus nematophila, and the insects they infect together. The nematode infective juveniles infect insects into which they release bacteria that help suppress insect immunity and kill the insect. The nematode-bacterium pair consume the insect cadaver and reproduce until nutrients are depleted, causing a new generation of infective juvenile nematodes, colonized by the bacterial symbiont, to leave the cadaver in search of insect prey. To begin to understand the processes by which insect biomass is converted over time to either nematode or bacterium biomass, we took a three-pronged approach integrating information from trophic, metabolomics, and gene regulation analyses. Trophic analysis established bacteria as the primary insect consumers, with nematodes at a trophic position of 4.37, indicating consumption of bacteria and likely also other nematodes. Metabolic changes associated with bioconversion of Galleria mellonella insects were assessed using multivariate statistical analyses of metabolomics datasets derived from sampling over an infection time course. Statistically significant, discrete phases were distinguishable from each other, indicating the insect chemical environment changes reproducibly during bioconversion. Tricarboxylic acid (TCA) cycle components and amino acids such as proline and leucine were significantly affected throughout the infection. Hierarchical clustering revealed a similar molecular abundance fluctuation pattern for nucleic acid, amino acid, and lipid biosynthesis metabolites. Together, these findings contribute to an ongoing understanding of how symbiont associations shape chemical environments.

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“…Electrophoretic mobility shift assay (EMSA) was carried out as described before with minor modification ( Zheng et al, 2018 ). Briefly, DNA fragments of the intergenic region of mexA-mexR were PCR amplified with indicated primers ( Supplementary Table 2 ).…”

Section: Methodsmentioning

confidence: 99%

A MexR Mutation Which Confers Aztreonam Resistance to Pseudomonas aeruginosa

Zhang

et al. 2021

Front. Microbiol.

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Therapy for Pseudomonas aeruginosa infections is hard due to its high natural and acquirable antibiotic resistance. After colonization in the hosts, P. aeruginosa commonly accumulates genomic mutations which confer them antibiotic resistance and better adaptations to the host environment. Deciphering the mechanisms of antibiotic resistance development in the clinical setting may provide critical insights into the design of effective combinatory antibiotic therapies to treat P. aeruginosa infections. In this work, we demonstrate a resistance mechanism to aztreonam of a clinical isolate (ARP36) in comparison with a sensitive one (CSP18). RNAseq and genomic DNA resequencing were carried out to compare the global transcriptional profiles and in the clinical setting genomic profiles between these two isolates. The results demonstrated that hyperexpression of an efflux pump MexAB-OprM caused by a R70Q substitution in MexR, contributed to the increased resistance to aztreonam in the isolate ARP36. Simulation of mexR of ARP36 by gene editing in CSP18 conferred CSP18 an ARP36-like susceptibility to the aztreonam. The R70Q substitution prevented MexR from binding to the intergenic region between mexR and mexAB-oprM operon, with no impact on its dimerization. The presented experimental results explain for the first time why the clinically relevant R70Q substitution in the MexR derepresses the expression of mexAB-oprM in P. aeruginosa.

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PutA Is Required for Virulence and Regulated by PruR in Pseudomonas aeruginosa

Cited by 11 publications

References 65 publications

Insights into the mechanism regulating the differential expression of the P28-OMP outer membrane proteins in obligatory intracellular pathogen Ehrlichia chaffeensis

Insights into the mechanism regulating the differential expression of the P28-OMP outer membrane proteins in obligatory intracellular pathogen Ehrlichia chaffeensis

Chemical ecology of an apex predator life cycle

A MexR Mutation Which Confers Aztreonam Resistance to Pseudomonas aeruginosa

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