Bacterial Heterochromatin Formation Through Liquid-Liquid Phase Separation
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ABSTRACT:
ORGANISM(S): Escherichia coli
PROVIDER: GSE174575 | GEO | 2021/12/23
REPOSITORIES: GEO
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Project description:Inorganic polyphosphate (polyP) is synthesized by bacteria in response to various stresses, but the mechanism of its regulation is unknown. Mutants of Escherichia coli lacking the RNA polymerase-binding transcription factor dksA are defective in polyP synthesis after a nutrient limitation stress, and this defect is reversed in a dksA greA mutant. In this work, we used RNA sequencing to compare transcription in wild-type, dksA, and dksA greA strains of E. coli before and after nutrient limitation, to identify genes whose expression pattern correlates with ability to synthesize polyP.
2020-03-11 | GSE144816 | GEO
Project description:Inorganic polyphosphate (Poly P) is a polymer of various phosphate residues linked by phosphoanhydride bonds as in ATP. It is found in all cells in nature with roles in the origin and survival of species, particularly in bacteria. To study the role of the inorganic polyphosphate in bacteria, we obtained knockout mutants of polyP metabolism genes in Escherichia coli K12. We performed DNA microarray experiments of single mutants in polyphosphate kinase 1 (PPK1), exopolyphosphatase (PPX) and also with the double mutant (PPK1 and PPX). The mutant strains growth normally in LB medium but have different colony morphology phenotypes. All mutants have flagellation problems and a detail description of all gain and lost phenotypes o these strains will be published soon because we performed a complete phenotypic microarray study of all three mutant strains.
2011-06-15 | GSE29954 | GEO
Project description:How biomolecules condense to organize subcellular processes is of fundamental significance. Nitrogen-starved Escherichia coli form a single condensate, which we termed Bacterial Stress Body (BSB). Its formation is triggered by long polyphosphate chains, which scaffold the RNA chaperone Hfq into high molecular weight complexes with distinct sequence-specific RNA and DNA binding properties. We show that polyP is crucial for the stabilization of select RNAs, the sequestration of translation- and RNA metabolism-associated proteins that likely stall protein synthesis, and the specific nucleoid-associated localization of BSBs. Together, these functions ensure bacterial survival and recovery from N-starvation. Mammalian polyphosphate associates with P-bodies but not stress granules suggesting that polyphosphate’s interaction with select RNA binding proteins contributed to the evolution of functionally and compositionally distinct condensates in higher organisms.
2024-04-01 | GSE241319 | GEO
Project description:How biomolecules condense to organize subcellular processes is of fundamental significance. Nitrogen-starved Escherichia coli form a single condensate, which we termed Bacterial Stress Body (BSB). Its formation is triggered by long polyphosphate chains, which scaffold the RNA chaperone Hfq into high molecular weight complexes with distinct sequence-specific RNA and DNA binding properties. We show that polyP is crucial for the stabilization of select RNAs, the sequestration of translation- and RNA metabolism-associated proteins that likely stall protein synthesis, and the specific nucleoid-associated localization of BSBs. Together, these functions ensure bacterial survival and recovery from N-starvation. Mammalian polyphosphate associates with P-bodies but not stress granules suggesting that polyphosphate’s interaction with select RNA binding proteins contributed to the evolution of functionally and compositionally distinct condensates in higher organisms.
2024-04-01 | GSE241317 | GEO
Project description:How biomolecules condense to organize subcellular processes is of fundamental significance. Nitrogen-starved Escherichia coli form a single condensate, which we termed Bacterial Stress Body (BSB). Its formation is triggered by long polyphosphate chains, which scaffold the RNA chaperone Hfq into high molecular weight complexes with distinct sequence-specific RNA and DNA binding properties. We show that polyP is crucial for the stabilization of select RNAs, the sequestration of translation- and RNA metabolism-associated proteins that likely stall protein synthesis, and the specific nucleoid-associated localization of BSBs. Together, these functions ensure bacterial survival and recovery from N-starvation. Mammalian polyphosphate associates with P-bodies but not stress granules suggesting that polyphosphate’s interaction with select RNA binding proteins contributed to the evolution of functionally and compositionally distinct condensates in higher organisms.
2024-04-01 | GSE241321 | GEO
Project description:Polyphosphate (polyP) is a ubiquitous and abundant compound found in bacteria, fungi, algae, plant, and animals. Among roles of intracellular polyP in bacteria are resistance and survival in the stationary phase of the growth against stress and stringent condition. Therefore, intracellular polyP is considered as a virulence factor of bacteria. In contrast, exogenous polyP has an antimicrobial activity against a variety of microorganisms. To date, much has been numerous studies of antibacterial effect of polyP against gram positive bacteria and fungi while relatively little reports have been published concerning gram negative bacteria. Here we describe bactericidal effect of polyP against gram negative periodontopathic bacterium, Porphyromonas gingivalis, and the transcriptional change by polyP in this bacterium. The bacterial growth was inhibited by polyP (chain length of P3~P75) at concentration of 0.02~0.03%, but not by Pi and PPi at the concentrations. polyP75 was chosen for further experiments, which suppressed the further growth of P. gingivalis as low as 0.03%. polyP75 completely killed the bacterial cells at the concentration of 0.035%. Microarray analysis was employed to identify genes that showed a greater than 1.5-fold difference in the expression by polyP75 at the concentration of 0.03%. It was found that 155 genes were up-regulated and 173 were down-regulated. Down-regulated genes include groups of energy metabolism-related genes, cell envelope-related genes, and genes in relation to biosynthesis of cofactors, prosthetic groups and carriers. Among the down-regulated genes were several involved in DNA replication, cell division protein, and biosynthesis of purines, pyrimidines, nucleosides and nucleotides. In contrast, a large number of ribosomal proteins, transciptional regulators and transposases were up-regulated. Oxidative stress-related genes and iron storage proteins also appeared to be increased in the expression. Real-time PCR confirmed up- and down-regulation of some selected genes. The overall results suggest that polyP has a bactericidal activity against P. gingivalis, interfering with translation, energy metabolism, DNA replication, cell division, and biosynthesis of purines, pyrimidines, nucleoside and nucleotides. polyP may be used as an agent for prevention and treatment of periodontal infections. Polyp-treated vs. untreated intensity ratio data linked below as a supplementary file. Keywords: agent response
2008-05-30 | GSE11471 | GEO
Project description:Staphylococcus aureus (S. aureus) is a known pathogen able to infect humans and animals. Human S. aureus isolates are often associated with carriage of Sa3int prophages combined with loss of beta-hemolysin production due to gene disruption, whereas animal isolates are positive for beta-hemolysin associated with absence of Sa3int prophages. Sa3int prophages are known to contribute to staphylococcal fitness and virulence in human host by providing human-specific virulence factors encoded on the prophage genome. Strain-specific differences in regard to phage transfer, lysogenization and induction are attributable to yet unknown staphylococcal factors specifically influencing prophage gene expression. In this work we used tagRNA-sequencing approach to specifically search for these unknown host factors and differences in prophage gene expression. For this purpose, we established a workflow revealing the first direct comparison for differential gene expression analysis on two distinct single-lysogenic S. aureus isolates. Further, global gene expression patterns were investigated in two S. aureus isolates upon mitomycin C treatment and compared to uninduced conditions. This provides new insights into the tightly linked host-phage interaction network.
2022-10-03 | GSE214523 | GEO
Project description:There is increasing evidence that microbes maintain a structured chromosome, which in turn impacts gene expression. However tools to profile the genome landscape and binding of key architectural proteins have been limited. We recently discovered densely occupied, multi-kilobase regions in E. coli that are transcriptionally silent, similar to eukaryotic heterochromatin. These regions, termed EPODs, overlap metabolic pathways and parasitic elements such as prophages. Here, we investigate the contributions of nucleoid associated proteins (NAPs) to these domains by examining the impacts of deleting NAPs on EPODs genome-wide in E. coli and an evolutionarily distant species, Bacillus subtilis. We identify key NAPs contributing to the silencing of specific EPODs, where deletion of a particular NAPs opens a chromosomal region to RNA polymerase binding. In E. coli, we distinguish novel xenogeneic silencing NAPs, Fis and Hfq, that are essential for cell viability in the presence of domesticated prophages. Furthermore, we show that changes in EPODs facilitate an extra layer of transcriptional regulation to prepare cells for exposure to exotic carbon sources. Our findings demonstrate a new suite of mechanisms through which genomic architecture primes bacteria for changing metabolic environments and silences harmful genomic elements
2021-10-01 | GSE164796 | GEO
Project description:Staphylococcus aureus is a Gram-positive human pathogen causing a variety of human diseases in both hospital and community settings. This bacterium is so closely associated with prophages that it is rare to find S. aureus isolates without prophages. Two phages are known to be important for staphylococcal virulence: the beta-hemolysin (hlb) converting phage and the Panton-Valentine Leukocidin (PVL) converting phage. The hlb-converting phage is found in more than 90% of clinical isolates of S. aureus. This phage produces exotoxins and immune modulatory molecules, which inhibit human innate immune responses. The PVL-converting phage produces the two-component exotoxin PVL, which can kill human leucocytes. This phage is wide-spread among community-associated methicillin resistant S. aureus (CA-MRSA). It also shows strong association with soft tissue infections and necrotizing pneumonia. Several lines of evidence suggest that staphylococcal prophages increase bacterial virulence not only by providing virulence factors but also by altering bacterial gene expression: 1) Transposon insertion into prophage regulatory genes, but not into the genes of virulence factors, reduced S. aureus killing of Caenorhabditis elegans.; 2) Although the toxins and immune modulatory molecules encoded by the hlb- converting phages do not function in the murine system, deletion of ϕNM3, the hlb-converting phage in S. aureus Newman, reduced staphylococcal virulence in the murine abscess formation model. 3) In a preliminary microarray experiment, prophages in S. aureus Newman altered the expression of more than 300 genes. In this research proposal, using microarray and high-throughput quantitative RT-PCR (qRT-PCR) technologies, we will identify the effects of the two important staphylococcal phages on the gene expression of S. aureus in both in vitro and in vivo conditions. This project is intended to be completed within one year. All the data – microarray, qRT-PCR and all the primer sequences- will be made available to public 6 month after completion. Data from this project will help us to understand the role of prophages in the S. aureus pathogenesis and can lead to development of a strategy to interfere with the pathogenesis process. Following strains were grown in TSA broth: Staphylococcus aureus USA300 (reference) Staphylococcus aureus USA300 with deletion of ϕSa2usa (Query) Staphylococcus aureus USA300 with deletion of ϕSa3usa (Query) Staphylococcus aureus USA300 Prophage-free mutant (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa2mw (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa3usa (Query) strain: Staphylococcus aureus USA300 Prophage-free mutant lysogenized with both ϕSa2mw and ϕSa3usa (Query) RNA samples were harvested at early log, midlog and stationary phase.Samples were hybridized on aminosilane coated slides with 70-mer oligos.
2011-02-28 | E-GEOD-26623 | biostudies-arrayexpress
Project description:In diverse cells from bacterial to mammalian species, inorganic phosphate is stored in long chains called polyphosphates (polyP). These near universal polymers, ranging from 3 to thousands of phosphate moieties in length, are associated with molecular functions including energy homeostasis, protein folding, and cell signaling. In many cell types, polyphosphate is concentrated in subcellular compartments or organelles. In the budding yeast S. cerevisiae, polyP synthesis by the membrane-bound VTC complex is coupled to its translocation into the lumen of the vacuole, a lysosome-related organelle, where it is stored at high concentrations. In contrast, ectopic expression of bacterial polyphosphate kinase, PPK, results in the toxic accumulation of polyP outside of the vacuole. In this study, we used label-free mass spectrometry to investigate the mechanisms underlying this toxicity. We find that PPK expression results in the activation of a stress response mediated in part by the Hog1 and Yak1 kinases, and Msn2/Msn4 transcription factors. This response is countered by the combined action of the Ddp1 and Ppx1 polyphosphatases that function together to counter polyP accumulation and downstream toxicity. In contrast, ectopic expression of previously proposed mammalian polyphosphatases did not impact PPK-mediated toxicity in the yeast model, suggesting either that these enzymes do not function directly as polyphosphatases in vivo or that they require co-factors unique to higher eukaryotes. Our work provides a mechanistic explanation for why polyP accumulation outside of lysosome-related organelles is toxic. Further, it serves as a resource for exploring how polyP may impact conserved biological processes at a molecular level.
2022-02-04 | PXD031326 | Pride