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ABSTRACT:
PROVIDER: PRJNA890467 | ENA |
REPOSITORIES: ENA
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Project description:Biofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of polysaccharides, proteins, and extracelluar (e)DNA, with eDNA being required for the formation and integrity of biofilms. Here we demonstrate that the spatial and temporal release of eDNA is regulated by BfmR, a regulator essential for Pseudomonas aeruginosa biofilm development. The expression of bfmR coincided with localized cell death and DNA release, with high eDNA concentrations localized to the outer part of microcolonies in the form of a ring and as a cap on small clusters. Additionally, eDNA release and cell lysis increased significantly following bfmR inactivation. Genome-wide transcriptional profiling indicated that bfmR was required for repression of genes associated with bacteriophage assembly and bacteriophage-mediated lysis. In order to determine which of these genes were directly regulated by BfmR, we utilized chromatin immunoprecipitation (ChIP) analysis to identify the promoter of PA0691, termed here phdA, encoding a previously undescribed homologue of the prevent-host-death (Phd) family of proteins. Lack of phdA expression coincided with impaired biofilm development, increased cell death and bacteriophage release, a phenotype comparable to ΔbfmR. Expression of phdA in ΔbfmR biofilms restored eDNA release, cell lysis, release of bacteriophages, and biofilm formation to wild type levels. Moreover, overexpression of phdA rendered P. aeruginosa resistant to lysis mediated by superinfective bacteriophage Pf4 which was only detected in biofilms. The expression of bfmR was stimulated by conditions resulting in membrane perturbation and cell lysis. Thus, we propose that BfmR regulates biofilm development by controlling bacteriophage-mediated lysis and thus, cell death and eDNA release, via PhdA. For biofilm growth experiments, three independent replicates of P. aeruginosa strains PAO1 and ΔbfmR were grown as biofilms in a flow-through system using a once-through continuous flow tube reactor system for biofilm sample collection and in flow cells (BioSurface Technologies) for the analysis of biofilm architecture as previously described (Sauer et al., 2002, Sauer et al., 2004, Petrova & Sauer, 2009). Cells were treated with RNAprotect (Qiagen), and total RNA was extracted using an RNeasy mini purification kit (Qiagen) per the manufacturer’s instructions. RNA quality and the presence of residual DNA were checked on an Agilent Bioanalyzer 2100 electrophoretic system pre- and post-DNase treatment. Ten micrograms of total RNA was used for cDNA synthesis, fragmentation, and labeling according to the Affymetrix GeneChip P. aeruginosa genome array expression analysis protocol. Sauer, K., A. K. Camper, G. D. Ehrlich, J. W. Costerton & D. G. Davies, (2002) Pseudomonas aeruginosa displays multiple phenotypes during development as a biofilm. J. Bacteriol. 184: 1140-1154. Sauer, K., M. C. Cullen, A. H. Rickard, L. A. H. Zeef, D. G. Davies & P. Gilbert, (2004) Characterization of nutrient-induced dispersion in Pseudomonas aeruginosa PAO1 biofilm. J. Bacteriol. 186: 7312-7326. Petrova, O. E. & K. Sauer, (2009) A novel signaling network essential for regulating Pseudomonas aeruginosa biofilm development. PLoS Pathogens 5: e1000668.
2011-06-01 | E-GEOD-28953 | biostudies-arrayexpress
Project description:Biofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of polysaccharides, proteins, and extracelluar (e)DNA, with eDNA being required for the formation and integrity of biofilms. Here we demonstrate that the spatial and temporal release of eDNA is regulated by BfmR, a regulator essential for Pseudomonas aeruginosa biofilm development. The expression of bfmR coincided with localized cell death and DNA release, with high eDNA concentrations localized to the outer part of microcolonies in the form of a ring and as a cap on small clusters. Additionally, eDNA release and cell lysis increased significantly following bfmR inactivation. Genome-wide transcriptional profiling indicated that bfmR was required for repression of genes associated with bacteriophage assembly and bacteriophage-mediated lysis. In order to determine which of these genes were directly regulated by BfmR, we utilized chromatin immunoprecipitation (ChIP) analysis to identify the promoter of PA0691, termed here phdA, encoding a previously undescribed homologue of the prevent-host-death (Phd) family of proteins. Lack of phdA expression coincided with impaired biofilm development, increased cell death and bacteriophage release, a phenotype comparable to ΔbfmR. Expression of phdA in ΔbfmR biofilms restored eDNA release, cell lysis, release of bacteriophages, and biofilm formation to wild type levels. Moreover, overexpression of phdA rendered P. aeruginosa resistant to lysis mediated by superinfective bacteriophage Pf4 which was only detected in biofilms. The expression of bfmR was stimulated by conditions resulting in membrane perturbation and cell lysis. Thus, we propose that BfmR regulates biofilm development by controlling bacteriophage-mediated lysis and thus, cell death and eDNA release, via PhdA.
2011-06-01 | GSE28953 | GEO
Project description:Androgen receptor (AR) is required for castration resistant prostate cancer (CRPC) progression, but the function and disease relevance of AR-bound enhancers remain poorly understood. Here, we identify a group of AR-regulated enhancer RNAs (e.g. PSA eRNA) that are upregulated in CRPC cells, patient-derived xenografts (PDX) and patient tissues. PSA eRNA binds to CYCLIN T1, activates P-TEFb and promotes in cis and trans gene transcription by increasing serine-2 phosphorylation of RNA polymerase II (Pol II-Ser2p). To avoid the total Pol II changing by PSA eRNA. We measured the total Pol II using N20 and 8WG16 antibodies with or without PSA eRNA knocking down. To avoid the AR binding changes by PSA eRNA, we also measured the AR binding using AR N20 antibodies with or without PSA eRNA knocking down. Androgen receptor (AR) binding sites in human prostate cancer cell lines, C4-2, were studied using ChIP-seq. Total Pol II Ser-2p and AR binding sites in human prostate cancer cell lines C4-2 with or without PSA eRNA knockdown, were studied using ChIP-seq. ChIP enriched DNA were sequenced using Illumina HiSeq 2500and input DNA were sequenced using Illumina HiSeq 2000.
2016-02-12 | E-GEOD-71704 | biostudies-arrayexpress
Project description:Transcriptional response of wildtype Phaeobacter inhibens to several secondary metabolites (AHLs, TDA) and eDNA
2021-05-04 | GSE126034 | GEO
Project description:Pseudomonas spp. isolated from Morchella spp.
| PRJNA1010354 | ENA
Project description:Pseudomonas aeruginosa, the type species of the Pseudomonas genus, is an environmental Gram negative bacterium, well-known for its ability to produce toxins, resist antibiotics, and opportunistically colonize various niches, including invertebrate and vertebrate hosts. P. aeruginosa produces redox active secondary metabolites called phenazines involved in quorum sensing, biofilm formation, virulence, and iron acquisition. Moreover, these colorful pigmented virulence factors act as ligands for the highly conserved aryl hydrocarbon receptor (AhR) thereby regulating antibacterial defenses in vertebrates. Pseudomonas spp. are some of the most frequently identified bacteria in larval and adult stages of wild mosquito populations. Here we investigated global transcriptional changes induced in A. coluzzii third instar larvae incubated with a sublethal concentration (50 µM) of 1-hydroxyphenazine (1-HP) or pyocyanin (Pyo) at 4 h and 8 h of continuous incubation by whole-genome DNA microarrays.
2018-03-01 | GSE89829 | GEO