Two transmembrane transcriptional regulators coordinate to activate chitin-induced natural transformation in Vibrio cholerae
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ABSTRACT:
PROVIDER: PRJNA1196982 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR31686539_1.fastq.gz | Fastqsanger.gz | |||
| SRR31686539_2.fastq.gz | Fastqsanger.gz | |||
| SRR31686540_1.fastq.gz | Fastqsanger.gz | |||
| SRR31686540_2.fastq.gz | Fastqsanger.gz |
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Project description:Transcriptional regulators are a broad class of proteins that alter gene expression in response to environmental stimuli. Transmembrane transcriptional regulators (TTRs) are a subset of transcriptional regulators in bacteria that can directly regulate gene expression while remaining anchored in the membrane. Whether this constraint impacts the ability of TTRs to bind their DNA targets remains unclear. Vibrio cholerae uses two TTRs, ChiS and TfoS, to activate horizontal gene transfer by natural transformation in response to chitin by inducing the tfoR promoter (PtfoR). While TfoS was previously shown to bind and regulate PtfoR directly, the role of ChiS in PtfoR activation remains unclear. Here, we show that ChiS directly binds PtfoR upstream of TfoS, and that ChiS directly interacts with TfoS. By independently disrupting ChiS-PtfoR and ChiS-TfoS interactions, we show that ChiS-PtfoR interactions play the dominant role in PtfoR activation. Correspondingly, we show that in the absence of ChiS, recruitment of the PtfoR locus to the membrane is sufficient for PtfoR activation when TfoS is expressed at native levels. Finally, we show that the overexpression of TfoS can bypass the need for ChiS for PtfoR activation. All together, these data suggest a model whereby ChiS both (1) recruits the PtfoR DNA locus to the membrane for TfoS and (2) directly interacts with TfoS to increase its local concentration near the membrane-proximal promoter. This work furthers our understanding of the molecular mechanisms that drive chitin-induced responses in V. cholerae and more broadly highlights how the membrane-embedded localization of TTRs can impact their activity.
2024-12-16 | GSE284091 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE3101: Chitin oligosaccharide induction GSE3102: Crab shell attachment GSE3103: Chitin sensor Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin. Refer to individual Series
2006-03-07 | E-GEOD-4388 | biostudies-arrayexpress
Project description:Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin. This SuperSeries is composed of the SubSeries listed below.
2006-03-08 | GSE4388 | GEO
Project description:Strawberry cultivation is associated with high mineral fertilizer doses and excessive use of chemical plant protection products. Based on previous research, we expected that chitin application to the growing medium will increase the nutrient availability and activate the plant’s systemic defense response, resulting in higher strawberry yields and less disease symptoms. We set up two experiments in which the temporal variability and differences in initial nutrient concentrations of the growing media were taken into account. Chitin induced the plant’s shoot biomass, explained by elevated N concentration in the growing medium and/or the attraction of plant-growth promoting fungal genera towards the plant root, such as Mortierella and Umbelopsis. The over-excessive N concentration and P and K deficiencies in the chitin treatment led to nutrient disbalances. This may explain the decreased fruit yield and disease resistance of the fruits towards Botrytis cinerea. In contrast, chitin caused a clear defense priming effect of the strawberry leaves, with a strong induction of the jasmonic acid response, resulting in less disease symptoms. Chitin caused positive effects on shoot growth and disease resistance of the leaves, but caution needs to be taken for nutrient disbalances leading to negative influences on fruit production and disease susceptibly.
2021-01-01 | GSE144526 | GEO
Project description:Chitin oligomers, released from fungal cell walls by endochitinase, induce defense and related cellular responses in many plants. However, little is known about chitin responses in the model plant Arabidopsis. We describe here a large scale characterization of gene expression patterns in Arabidopsis in response to chitin treatment using an Arabidopsis microarray consisting of 2,375 EST clones representing putative defense-related and regulatory genes. Transcript levels for 71 ESTs, representing 61 genes, were altered >3-fold in chitin-treated seedlings relative to control seedlings. A number of transcripts exhibited altered accumulation as early as 10 min after exposure to chitin, representing some of the earliest changes in gene expression observed in chitin-treated plants. Included among the 61 genes are those that have been reported to be elicited by various pathogen-related stimuli in other plants. Additional genes, including genes of unknown function, were also identified broadening our understanding of chitin-elicited responses. Among transcripts with enhanced accumulation, one cluster was enriched in genes with both the W-box promoter element and a novel regulatory element. In addition, a number of transcripts had decreased abundance, encoding several proteins involved in cell wall strengthening and wall deposition. The chalcone synthase promoter element was identified in the upstream regions of these genes, suggesting that pathogen signals may suppress expression of some genes. These data indicate that Arabidopsis will be an excellent model to elucidate mechanisms of chitin elicitation in plant defense. Groups of assays that are related as part of a time series. Keywords: time_series_design
2005-09-09 | GSE3273 | GEO
Project description:Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis seedlings to chito-tetramers, chito-octamers and hydrolyzed chitin after 30 min of treatment. Keywords = chitin Keywords = defense Keywords = elicitor Keywords = mutant Keywords = powdery mildew Keywords = Erysiphe cichoracearum Keywords: ordered
2005-06-01 | GSE2538 | GEO
Project description:External signals are key for bacteria to sense their immediate environment and fine-tune gene expression accordingly. The foodborne pathogen Listeria monocytogenes senses a range of environmental cues in order to activate or deactivate the virulence-inducing transcriptional factor PrfA during transition between infectious and saprophytic lifecycles. Chitin is an abundant biopolymer formed from linked β-(1–4)-N-acetyl-D-glucosamine residues associated with fungi, the exoskeleton of insects and often incorporated into foods as a thickener or stabiliser. L. monocytogenes evolved to hydrolyse chitin, presumably, to facilitate nutrient acquisition from competitive environments such as soil where the polymer is abundant. Since mammals do not produce chitin, we reasoned that the polymer could serve as an environmental signal contributing to repression of L. monocytogenes PrfA-dependent expression outside the host. This study shows a significant downregulation of the core PrfA-regulon during virulence-inducing conditions in vitro in the presence of chitin. Our data suggest this phenomenon occurs through a mechanism that differs from PTS-transport of oligosaccharides generated from either degradation or chitinase-mediated hydrolysis of the polymer. Importantly, an indication that chitin can repress virulence expression of a constitutively active PrfA* mutant is shown, possibly mediated via a post-translational modification inhibiting PrfA* activity. To our knowledge, chitin as a molecule with anti-virulence properties against a pathogenic bacterium has not been previously reported. Thus, our findings identify chitin as a signal which may downregulate the virulence potential of the pathogen and may provide an alternative approach towards reducing disease risk.
2020-12-22 | GSE154844 | GEO
Project description:Chitin oligomers, released from fungal cell walls by endochitinase, induce defense and related cellular responses in many plants. However, little is known about chitin responses in the model plant Arabidopsis. We describe here a large scale characterization of gene expression patterns in Arabidopsis in response to chitin treatment using an Arabidopsis microarray consisting of 2,375 EST clones representing putative defense-related and regulatory genes. Transcript levels for 71 ESTs, representing 61 genes, were altered >3-fold in chitin-treated seedlings relative to control seedlings. A number of transcripts exhibited altered accumulation as early as 10 min after exposure to chitin, representing some of the earliest changes in gene expression observed in chitin-treated plants. Included among the 61 genes are those that have been reported to be elicited by various pathogen-related stimuli in other plants. Additional genes, including genes of unknown function, were also identified broadening our understanding of chitin-elicited responses. Among transcripts with enhanced accumulation, one cluster was enriched in genes with both the W-box promoter element and a novel regulatory element. In addition, a number of transcripts had decreased abundance, encoding several proteins involved in cell wall strengthening and wall deposition. The chalcone synthase promoter element was identified in the upstream regions of these genes, suggesting that pathogen signals may suppress expression of some genes. These data indicate that Arabidopsis will be an excellent model to elucidate mechanisms of chitin elicitation in plant defense. Groups of assays that are related as part of a time series. Keywords: time_series_design Computed
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Project description:Strain N16961 grown in M9 + 0.5 % lactate to OD 0.2. Culture was split and one part added 0.6 mM of indicated chitin oligosaccharide. Samples was isolated after 30 and 60 min. cDNA was prepared from 2 ug RNA and labeled with Cy3 (no induction) and Cy5 (induction with chitin oligosaccharide). Samples from at least two independent experiments and a total of four hybridizations for each chitin oligosaccharide and time. A growth condition experiment design type is where some part of the growth condition is changed for the purposes of the experiment, examples of growth conditions changed are media, temperature, humidity, light, nutrients. Using regression correlation
2005-08-11 | E-GEOD-3101 | biostudies-arrayexpress