Effect of the luxI/R gene on AHL-signaling molecules and QS regulatory mechanism in Hafnia alvei H4

Li, Xue; Zhang, Gongliang; Zhu, Yaolei; Bi, Jingran; Hao, Hongshun; Hou, Hongman

doi:10.1186/s13568-019-0917-z

Cited by 20 publications

(11 citation statements)

References 62 publications

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“…The binding specificity of AHL and LuxR is very strong because the specificity of AHL is controlled by different acyl side chain groups. Therefore, Gram-negative bacteria use this method to achieve the transfer of information between cells within the species, which will avoid interference caused by external bacteria [46,47]. The signal molecule represented by furan borate diester [48,49], which is represented by AI-2, can be used as a quorum-sensing signal molecule in both Gram-negative and Gram-positive bacteria.…”

Section: Microbial Quorum Sensing System and Its Regulation Mechanismmentioning

confidence: 99%

Quorum-Sensing Regulation of Antimicrobial Resistance in Bacteria

2020

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Quorum sensing is a cell-to-cell communication system that exists widely in the microbiome and is related to cell density. The high-density colony population can generate a sufficient number of small molecule signals, activate a variety of downstream cellular processes including virulence and drug resistance mechanisms, tolerate antibiotics, and harm the host. This article gives a general introduction to the current research status of microbial quorum-sensing systems, focuses on the role of quorum-sensing systems in regulating microbial resistance mechanisms, such as drug efflux pump and microbial biofilm formation regulation, and discusses a new strategy for the treatment of drug-resistant bacteria proposed by using quorum quenching to prevent microbial resistance.

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Section: Microbial Quorum Sensing System and Its Regulation Mechanismmentioning

confidence: 99%

Quorum-Sensing Regulation of Antimicrobial Resistance in Bacteria

2020

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“…In our previous study, we have reported that the QS systems of Hafnia alvei H4 consists of AHLs synthase encoded by luxI gene and AHLs homologous receptors encoded by luxR gene ( Li X. et al, 2019 ), which involved in the density-dependent biological processes including food spoilage and virulence formation ( Blana et al, 2017 ; Li T. T. et al, 2019 ), through transcription regulation of target genes via AHL-LuxR dimerization-mediated signaling cascades. Thus, in this study, we used this bacterium as a model organism, and compared and analyzed the transcriptome data of its luxI/R -mediated QS and GPDM to exploit the influence of these regulation on the metabolism and to gain insight into the favorable control of density-dependent metabolic pathways.…”

Section: Introductionmentioning

confidence: 99%

Quorum Sensing-Mediated and Growth Phase-Dependent Regulation of Metabolic Pathways in Hafnia alvei H4

et al. 2021

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Quorum sensing (QS) is a widespread regulatory mechanism in bacteria used to coordinate target gene expression with cell density. Thus far, little is known about the regulatory relationship between QS and cell density in terms of metabolic pathways in Hafnia alvei H4. In this study, transcriptomics analysis was performed under two conditions to address this question. The comparative transcriptome of H. alvei H4 wild-type at high cell density (OD600 = 1.7) relative to low cell density (OD600 = 0.3) was considered as growth phase-dependent manner (GPDM), and the transcriptome profile of luxI/R deletion mutant (ΔluxIR) compared to the wild-type was considered as QS-mediated regulation. In all, we identified 206 differentially expressed genes (DEGs) mainly presented in chemotaxis, TCA cycle, two-component system, ABC transporters and pyruvate metabolism, co-regulated by the both density-dependent regulation, and the results were validated by qPCR and swimming phenotypic assays. Aside from the co-regulated DEGs, we also found that 59 DEGs, mediated by density-independent QS, function in pentose phosphate and histidine metabolism and that 2084 cell-density-dependent DEGs involved in glycolysis/gluconeogenesis and phenylalanine metabolism were influenced only by GPDM from significantly enriched analysis of transcriptome data. The findings provided new information about the interplay between two density-dependent metabolic regulation, which could assist with the formulation of control strategies for this opportunistic pathogen, especially at high cell density.

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“…In many cases, luxR can both activate and suppress the luxI gene ( Lequette et al, 2006 ). A study by Li et al (2019) suggested that LuxR protein might regulate AHL expression either positively or negatively. When the AHL is present alone, it might be positively or negatively regulate the expression of the luxI gene and expressing more or lesser C4-HSL or C6-HSL.…”

Section: Discussionmentioning

confidence: 99%

Functional characterization of quorum sensing LuxR-type transcriptional regulator, EasR in Enterobacter asburiae strain L1

Lau

How

Yin

et al. 2020

PeerJ

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Over the past decades, Enterobacter spp. have been identified as challenging and important pathogens. The emergence of multidrug-resistant Enterobacteria especially those that produce Klebsiella pneumoniae carbapenemase has been a very worrying health crisis. Although efforts have been made to unravel the complex mechanisms that contribute to the pathogenicity of different Enterobacter spp., there is very little information associated with AHL-type QS mechanism in Enterobacter spp. Signaling via N-acyl homoserine lactone (AHL) is the most common quorum sensing (QS) mechanism utilized by Proteobacteria. A typical AHL-based QS system involves two key players: a luxI gene homolog to synthesize AHLs and a luxR gene homolog, an AHL-dependent transcriptional regulator. These signaling molecules enable inter-species and intra-species interaction in response to external stimuli according to population density. In our recent study, we reported the genome of AHL-producing bacterium, Enterobacter asburiae strain L1. Whole genome sequencing and in silico analysis revealed the presence of a pair of luxI/R genes responsible for AHL-type QS, designated as easI/R, in strain L1. In a QS system, a LuxR transcriptional protein detects and responds to the concentration of a specific AHL controlling gene expression. In E. asburiae strain L1, EasR protein binds to its cognate AHLs, N-butanoyl homoserine lactone (C4-HSL) and N–hexanoyl homoserine lactone (C6-HSL), modulating the expression of targeted genes. In this current work, we have cloned the 693 bp luxR homolog of strain L1 for further characterization. The functionality and specificity of EasR protein in response to different AHL signaling molecules to activate gene transcription were tested and validated with β-galactosidase assays. Higher β-galactosidase activities were detected for cells harboring EasR, indicating EasR is a functional transcriptional regulator. This is the first report documenting the cloning and characterization of transcriptional regulator, luxR homolog of E. asburiae.

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Effect of the luxI/R gene on AHL-signaling molecules and QS regulatory mechanism in Hafnia alvei H4

Cited by 20 publications

References 62 publications

Quorum-Sensing Regulation of Antimicrobial Resistance in Bacteria

Quorum-Sensing Regulation of Antimicrobial Resistance in Bacteria

Quorum Sensing-Mediated and Growth Phase-Dependent Regulation of Metabolic Pathways in Hafnia alvei H4

Functional characterization of quorum sensing LuxR-type transcriptional regulator, EasR in Enterobacter asburiae strain L1

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