Bacterial Stress Bodies – Ancestral Condensates Regulating RNA Turnover and Protein Translation II
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ABSTRACT:
ORGANISM(S): Escherichia coli str. K-12 substr. MG1655
PROVIDER: GSE241319 | GEO | 2024/04/01
REPOSITORIES: GEO
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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: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
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: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:The emergence of hypervirulent Klebsiella pneumoniae (hvKP) strains poses a significant threat to public health due to their high mortality rates and propensity to cause severe community-acquired infections in otherwise healthy individuals. The ability of hvKP to form biofilms and produce a protective capsule contributes to its enhanced virulence and is a significant challenge to effective antibiotic treatment. Therefore, understanding the molecular mechanisms underlying hvKP virulence and biofilm formation is crucial for developing new therapeutic strategies. Polyphosphate Kinase 1 (PPK1) is an enzyme responsible for inorganic polyphosphate synthesis and plays a vital role in regulating various physiological processes in bacteria. In this study, we investigated the impact of polyP metabolism on the biofilm and capsule formation and virulence traits in hvKP using Dictyostelium discoideum amoeba as a model host. We found that the PPK1 null-mutant was impaired in biofilm and capsule formation and showed attenuated virulence in D. discoideum compared to the wild-type strain. We performed a shotgun proteomic analysis of the PPK1 mutant and wild-type strain to gain further insight into the underlying molecular mechanism. The results revealed that the PPK1 mutant had a differential expression of proteins (DEP) involved in capsule synthesis (Wzi - Ugd), biofilm formation (MrkC-D-H), synthesis of the colibactin genotoxin precursor (ClbB), as well as proteins associated with the synthesis and modification of lipid A (ArnB -LpxC - PagP). These proteomic findings corroborate the phenotypic observations and indicate that the PPK1 mutation is associated with impaired biofilm and capsule formation and attenuated virulence in hypervirulent K. pneumoniae. Overall, our study highlights the importance of polyP synthesis in regulating extracellular biomolecules and virulence in K. pneumoniae and provides insights into potential therapeutic targets for treating K. pneumoniae infections.
2024-08-23 | PXD046644 | Pride
Project description:The existing literature points towards the presence of robust mitochondrial mechanisms aimed at mitigating protein dyshomeostasis within the organelle. However, the precise molecular composition underlying these mechanisms remains unclear. Our data show that inorganic polyphosphate (polyP), a polymer well-conserved throughout evolution, is a component of these mechanisms. In mammals, mitochondria exhibit a significant abundance of polyP, and both our research and that of others have already highlighted its potent regulatory effect on bioenergetics. Given the intimate connection between energy metabolism and protein homeostasis, the involvement of polyP in proteostasis has also been demonstrated in several organisms. For example, polyP is a bacterial primordial chaperone, and its role in amyloidogenesis has already been established. Here, using HEK293 cells, our study reveals that the depletion of mitochondrial polyP leads to increased protein aggregation within the organelle, following stress exposure. Furthermore, mitochondrial polyP is able to bind to proteins, and these proteins differ under control and stress conditions. The depletion of mitochondrial polyP significantly affects the proteome under both control and stress conditions, while also exerting regulatory control over gene expression. Our findings suggest that mitochondrial polyP is a previously unrecognized, and potent component of mitochondrial proteostasis. The mass spectrometric raw files for this study are deposited here.
2024-06-28 | MSV000095178 | MassIVE
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:Heterochromatin is most often associated with eukaryotic organisms. Yet, bacteria also contain areas with densely protein-occupied chromatin that silences gene expression. One nucleoid-associated silencing factor is Hfq, which is strongly enriched at prophages and mobile genetic elements. Here we demonstrate that polyphosphate, an ancient and highly conserved polyanion, is essential for the specific binding of Hfq to these regions. Lack of either polyphosphate or Hfq causes unsolicited prophage and transposon mobilization, which drastically increases mutagenesis. We discovered that Hfq and polyphosphate form high molecular weight complexes that interact with DNA in phase-separated viscous condensates. We propose that polyP provides a scaffold that promotes Hfq binding to DNA regions with high intrinsic curvature, and thus serves as one hitherto unknown driver of heterochromatin formation in bacteria.
2021-12-23 | GSE174575 | 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 Twenty μg of each total RNA sample was used in separate hybridization experiments on identical arrays. The whole genome of 1,909 genes of P. gingivalis W83 (GenBank accession no. NC_002950) was submitted to NimbleGen System Inc. (Madison, WI) for microarray design and manufacture using maskless, digital micromirror technology. Five replicates of the genome were included per chip. An average of 19 different 60-base oligonucleotides (60-mer probes) represented each gene in the genome. Sixty-mer probes were selected such that each probe had at least three mismatches compared to all other 60-mers in the target genome. A quality control check (hybridization) was performed for each array, which contained on-chip control oligonucleotides. The arrays were analyzed using an Axon GenePix 4000B microarray scanner with associated software (Molecular Devices Corp., Sunnyvale, CA). Gene expression levels were calculated with NimbleScan Version 2.3 (NimbleGen). Relative signal intensities for each gene were generated using the Robust Multi-Array Average algorithm. The data were processed based on quantile normalization method using the R package. This normalization method aims to make the distribution of intensities for each array in a set of arrays the same. The background-adjusted, normalized, and log transformed intensity values were then analyzed using GeneSpring GX 7.3.1 (Silicon Genetics, Palo Alto, CA).
2008-05-30 | E-GEOD-11471 | biostudies-arrayexpress