Hierarchical transcriptional regulation of quorum sensing genes in Vibrio harveyi
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ABSTRACT:
PROVIDER: PRJNA602513 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR10919700.fastq.gz | Fastqsanger.gz | |||
| SRR10919701.fastq.gz | Fastqsanger.gz | |||
| SRR10919702.fastq.gz | Fastqsanger.gz | |||
| SRR10919703.fastq.gz | Fastqsanger.gz | |||
| SRR10919704.fastq.gz | Fastqsanger.gz |
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Project description:Quorum sensing controls hundreds of genes in vibrios required for cell density-specific behaviors, including bioluminescence, biofilm formation, competence, secretion, and motility. The central regulator in the quorum sensing pathway in vibrios is LuxR/HapR, which directly regulates >100 genes in the 625-gene regulon of Vibrio harveyi. Among these directly regulated genes are 15 transcription factors, which we predicted would comprise the second tier in the hierarchy of the quorum sensing regulon. To better study the mechanism of regulation of the quorum sensing network, we mapped all transcriptional start sites in V. harveyi using dRNA-seq. From these data, we determined the relative position of LuxR binding sites in the promoters of genes directly regulated by LuxR. We confirmed that LuxR directly binds to the promoters of the genes encoding transcription factors and quantified the extent of LuxR activation or repression of transcript levels. Finally, we determined the individual regulons for a subset of transcription factors that have not been previously studied. For regulators such as LysR- or AsnC/Lrp-type transcription factors, the regulons contained >100 genes that contained both unique and overlapping genes with the LuxR regulon. These data support a model in which LuxR directly regulates other transcription factors, which act to further alter the second tier of the gene expression cascade producing cell density behaviors in V. harveyi.
2020-05-15 | GSE144017 | GEO
Project description:LuxR is the master quorum sensing regulator in Vibrio harveyi. This transcription factor controls the expression of over 600 genes to coordinate group behaviors. In order to understand how LuxR regulates transcription we identified a co-regulator, integration host factor (IHF). In this study we performed RNA-seq to show that the LuxR and IHF regulons overlap significantly.
2017-12-03 | GSE90845 | GEO
Project description:Vibrio campbellii BB120 (ATCC BAA-1116, previously designated as Vibrio harveyi) is a fundamental model strain for studying population density-based cell-to-cell communication, known as quorum sensing, among gram-negative bacteria. In V. campbellii BB120, sensing of autoinducers at high cell densities activates the expression of the master transcriptional regulator, LuxR, which controls the expression of genes involved in group behaviors. Unlike BB120, the Vibrio campbellii environmental isolate DS40M4 was recently shown to be capable of natural transformation, a process by which bacteria take up exogenous DNA and incorporate it into their genome via homologous recombination. Here, we compare other phenotypes between DS40M4 and BB120. We find that DS40M4 has a faster growth rate and stronger type VI secretion-mediated cell killing, whereas BB120 forms more robust biofilms and is bioluminescent. We exploited the power of natural transformation to rapidly generate >30 mutant strains to explore the function of DS40M4-encoded homologs of the BB120 quorum-sensing system. Our results show that DS40M4 has a similar quorum-sensing circuit to BB120 but with three distinct differences: 1) DS40M4 lacks the canonical HAI-1 autoinducer LuxM synthase but has an active LuxN receptor, 2) the quorum regulatory small RNAs (Qrrs) are not solely regulated by autoinducer signaling through the response regulator LuxO, and 3) the DS40M4 LuxR regulon is <100 genes, which is relatively small compared to the >400 genes regulated in BB120. This work illustrates that DS40M4 is a tractable and relevant model strain for studying quorum-sensing phenotypes in Vibrio campbellii.
2021-06-28 | GSE147616 | GEO
Project description:The quorum regulatory cascade is poorly characterized in Vibrio parahaemolyticus, in part because swarming and pathogenicity - the hallmark traits of the organism - are repressed by this scheme of gene control. As a consequence, many isolates appear silenced for quorum sensing via phase variation. In these studies, we examine a swarm proficient, virulent strain and find an altered function allele of the central quorum regulator luxO. We use this allele, which produces a constitutively active LuxO, to probe the upstream elements of the pathway and demonstrate their functionality for the first time. We find that the state of luxO affects expression of three small regulatory RNAS (Qrrs) and the activity of a translational fusion in opaR, the central output regulator. We use microarray profiling to determine the OpaR regulon, which was found to encompass ~5.2% of the genome. The quorum sensing proficient strain seems adapted for a sessile, community lifestyle; it is competent to uptake DNA, produces much capsular polysaccharide, has a high level of c-di-GMP, and strongly expresses one type six secretion system. Expressing the entire surface sensing regulon and numerous methyl accepting chemotaxis proteins, the quorum-disrupted cell type seems prepared for a mobile lifestyle. It is also cytotoxic to host cells in co-culture and expresses distinct type six as well as type three secretion systems. Thus, the scope and nature of the genes in the OpaR regulon provide many clues to the distinguishing traits of this Vibrio species as well as to the quite divergent survival strategies of the quorum ON/OFF phase variants The gene expression profiles of different strains of Vibrio parahaemolyticus cells grown on rich medium and compared using Affymetrix custom microarrays.
2011-12-01 | E-GEOD-28216 | biostudies-arrayexpress
Project description:The quorum regulatory cascade is poorly characterized in Vibrio parahaemolyticus, in part because swarming and pathogenicity - the hallmark traits of the organism - are repressed by this scheme of gene control. As a consequence, many isolates appear silenced for quorum sensing via phase variation. In these studies, we examine a swarm proficient, virulent strain and find an altered function allele of the central quorum regulator luxO. We use this allele, which produces a constitutively active LuxO, to probe the upstream elements of the pathway and demonstrate their functionality for the first time. We find that the state of luxO affects expression of three small regulatory RNAS (Qrrs) and the activity of a translational fusion in opaR, the central output regulator. We use microarray profiling to determine the OpaR regulon, which was found to encompass ~5.2% of the genome. The quorum sensing proficient strain seems adapted for a sessile, community lifestyle; it is competent to uptake DNA, produces much capsular polysaccharide, has a high level of c-di-GMP, and strongly expresses one type six secretion system. Expressing the entire surface sensing regulon and numerous methyl accepting chemotaxis proteins, the quorum-disrupted cell type seems prepared for a mobile lifestyle. It is also cytotoxic to host cells in co-culture and expresses distinct type six as well as type three secretion systems. Thus, the scope and nature of the genes in the OpaR regulon provide many clues to the distinguishing traits of this Vibrio species as well as to the quite divergent survival strategies of the quorum ON/OFF phase variants
2011-12-01 | GSE28216 | GEO
Project description:We report that ChIP-seq analyses of the quorum-sensing regulator OpaR at late-log and stationary phase in Vibrio parahaemolyticus
2020-10-27 | GSE122479 | GEO
Project description:Vibrio campbellii BAA-1116 was used as model organism from the Harveyi clade to understand how melanization affected cellular phenotype, metabolism and virulence. An in-frame deletion of the homogentisate-1,2-dioxygenase (hmgA) gene resulted in the overproduction of a pigment in cell culture supernatants and cellular membranes that was identified as pyomelanin. Unlike previous demonstrations in Vibrio cholerae, Burkholderia cepacia and Pseudomonas aeruginosa, the pigmented V. campbellii mutant did not show increased UV or hydrogen peroxide resistance and was found to be ~2.7 times less virulent then the wild type strain in Penaeus monodon shrimp virulence assays. Microarray-based transcriptomic analyses revealed that the deletion of the hmgA gene and subsequent pyomelanin production negatively effected the expression of 129 genes involved in protein translation, cell division, membrane transport, electron transfer and amino acid utilization. The response was mediated in part by an impairment of the quorum sensing regulon as transcripts of the quorum sensing high cell density master regulator LuxR and other operonic members of this regulon were significantly repressed in the hmgA mutant. Taken together, the results suggest that the pyomelanization of V. campbellii sufficiently impairs the metabolic activities of this organism and renders it less fit and virulent then its isogenic wild type strain.
2013-05-31 | GSE46223 | GEO
Project description:Differential RNA-Seq data for Vibrio campbellii BB120 (ATCC BAA-1116, previously designated as Vibrio harveyi)
2024-07-15 | GSE182898 | GEO
Project description:Objectives: determination of transcription start sites in Vibrio harveyi genome and discovery of new transcripts Methods: we performed differential seqencing of total RNA isolated from o.n. control Vibrio harveyi cultures. Sample treatment with Terminator EXonuclease (TEX) allowed differenciation of primary and secondary transcripts, helping in the definition of transcription start sites (TSS) Results: by data-mining RNA-seq data and performing some Northern Blot experiments we were able to detect new putative small-RNAs, along with these results, a more deep analisys of our RNA-seq data will give futher insight into genetic organization of Vibrio harveyi genome to help in its investigation
2018-03-27 | GSE105060 | GEO
Project description:Bacteria coordinate cellular behaviors using a cell-cell communication system termed quorum sensing. In Vibrio harveyi, the master quorum sensing transcriptional factor LuxR directly regulates >100 genes in response to changes in population density. Here, we show that LuxR derepresses quorum sensing loci by competing with H-NS, a global transcriptional repressor that oligomerizes on DNA to form filaments and bridges. We first identified H-NS as a repressor of bioluminescence gene expression, for which LuxR is a required activator. In an hns deletion strain, LuxR is no longer necessary for transcription activation of the bioluminescence genes, suggesting that the primary role of LuxR is to displace H-NS to derepress gene expression. Using RNA-seq and ChIP-seq, we determined that H-NS and LuxR co-regulate and co-occupy 28 promoters driving expression of 63 genes across the genome. ChIP-PCR assays show that as autoinducer concentration increases, LuxR protein accumulates at co-occupied promoters while H-NS protein disperses. LuxR is sufficient to evict H-NS from promoter DNA in vitro, which is dependent on LuxR DNA binding activity. From these findings, we propose a model in which LuxR serves as a counter-silencer at H-NS-repressed quorum sensing loci by disrupting H-NS nucleoprotein complexes that block transcription.
2019-11-01 | GSE136050 | GEO