Understanding the roles of dksA and greA in inorganic polyphosphate accumulation in Escherichia coli
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ABSTRACT:
PROVIDER: PRJNA604995 | ENA |
REPOSITORIES: ENA
Dataset's files
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| SRR11028578.fastq.gz | Fastqsanger.gz | |||
| SRR11028579.fastq.gz | Fastqsanger.gz | |||
| SRR11028580.fastq.gz | Fastqsanger.gz | |||
| SRR11028581.fastq.gz | Fastqsanger.gz | |||
| SRR11028582.fastq.gz | Fastqsanger.gz |
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Similar Datasets
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:Understanding the roles of dksA and greA in inorganic polyphosphate accumulation in Escherichia coli
| PRJNA604995 | ENA
Project description:The stringent response, involving the regulatory molecules inorganic polyphosphate (poly P) and (p)ppGpp, is believed to mediate Mycobacterium tuberculosis persistence. In this study, we identified a novel exopolyphosphatase responsible for poly P hydrolysis. Using two different poly P-accumulating M. tuberculosis recombinant strains, we found that increased poly P content drives the organisms into early growth arrest, and contributes to tolerance to the cell wall-active agent isoniazid, increased resistance to stress conditions, and improved survival in macrophages. Transcriptomic and metabolomics analysis revealed metabolic downshift manifested by reduced expression of the transcriptional and translational machinery, and shift from utilization of glucose as a carbon source. In summary, regulation of the poly P balance is critical for persister formation in M. tuberculosis. The transcriptome of poly P accumulation strains, Rv1026 knock-down and ppk1 knock-in were compared to empty vector strains by RNA-seq.
2015-02-20 | E-GEOD-57868 | biostudies-arrayexpress
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:The stringent response, involving the regulatory molecules inorganic polyphosphate (poly P) and (p)ppGpp, is believed to mediate Mycobacterium tuberculosis persistence. In this study, we identified a novel exopolyphosphatase responsible for poly P hydrolysis. Using two different poly P-accumulating M. tuberculosis recombinant strains, we found that increased poly P content drives the organisms into early growth arrest, and contributes to tolerance to the cell wall-active agent isoniazid, increased resistance to stress conditions, and improved survival in macrophages. Transcriptomic and metabolomics analysis revealed metabolic downshift manifested by reduced expression of the transcriptional and translational machinery, and shift from utilization of glucose as a carbon source. In summary, regulation of the poly P balance is critical for persister formation in M. tuberculosis.
2015-02-20 | GSE57868 | GEO
Project description:Production of inorganic polyphosphate (polyP) by bacteria is triggered by a variety of different stress conditions. polyP is required for stress survival and virulence in diverse pathogenic microbes. Previous studies have hypothesized a model for regulation of polyP synthesis in which production of the stringent-response second messenger (p)ppGpp directly stimulates polyP accumulation. In this work, I have now shown that this model is incorrect, and (p)ppGpp is not required for polyP synthesis in Escherichia coli However, stringent mutations of RNA polymerase that frequently arise spontaneously in strains defective in (p)ppGpp synthesis and null mutations of the stringent-response-associated transcription factor DksA both strongly inhibit polyP accumulation. The loss of polyP synthesis in a mutant lacking DksA was reversed by deletion of the transcription elongation factor GreA, suggesting that competition between these proteins for binding to the secondary channel of RNA polymerase plays an important role in controlling polyP activation. These results provide new insights into the poorly understood regulation of polyP synthesis in bacteria and indicate that the relationship between polyP and the stringent response is more complex than previously suspected.IMPORTANCE Production of polyP in bacteria is required for virulence and stress response, but little is known about how bacteria regulate polyP levels in response to changes in their environments. Understanding this regulation is important for understanding how pathogenic microbes resist killing by disinfectants, antibiotics, and the immune system. In this work, I have clarified the connections between polyP regulation and the stringent response to starvation stress in Escherichia coli and demonstrated an important and previously unknown role for the transcription factor DksA in controlling polyP levels.
| S-EPMC6456864 | biostudies-literature
Project description:Bacteria synthesize inorganic polyphosphate (polyP) in response to a variety of different stress conditions. polyP protects bacteria by acting as a protein-stabilizing chaperone, metal chelator, or regulator of protein function, among other mechanisms. However, little is known about how stress signals are transmitted in the cell to lead to increased polyP accumulation. Previous work in the model enterobacterium Escherichia coli has indicated that the RNA polymerase-binding regulatory protein DksA is required for polyP synthesis in response to nutrient limitation stress. In this work, I set out to characterize the role of DksA in polyP regulation in more detail. I found that overexpression of DksA increases cellular polyP content (explaining the long-mysterious phenotype of dksA overexpression rescuing growth of a dnaK mutant at high temperatures) and characterized the roles of known functional residues of DksA in this process, finding that binding to RNA polymerase is required but that none of the other functions of DksA appear to be necessary. Transcriptomics revealed genome-wide transcriptional changes upon nutrient limitation, many of which were affected by DksA, and follow-up experiments identified complex interactions between DksA and the stress-sensing alternative sigma factors FliA, RpoN, and RpoE that impact polyP production, indicating that regulation of polyP synthesis is deeply entwined in the multifactorial stress response network of E. coliIMPORTANCE Inorganic polyphosphate (polyP) is an evolutionarily ancient, widely conserved biopolymer required for stress resistance and pathogenesis in diverse bacteria, but we do not understand how its synthesis is regulated. In this work, I gained new insights into this process by characterizing the role of the transcriptional regulator DksA in polyP regulation in Escherichia coli and identifying previously unknown links between polyP synthesis and the stress-responsive alternative sigma factors FliA, RpoN, and RpoE.
| S-EPMC7317045 | biostudies-literature
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:Inorganic polyphosphate abets silencing of a sub-telomeric gene cluster in fission yeast
| PRJNA881297 | ENA
Project description:Strains devoid of ppGpp (ΔrelA ΔspoT; called ppGpp0), and ppGpp0 dksA- exhibit several amino acid requirements for growth on minimal media. We found that overexpression of DksA can complement some of those requirements. Since DksA is a factor that binds to the RNA polymerase secondary channel, we wondered if other secondary channel proteins might also exert a similar role with respect to growth on minimal media. In our study we found that GreA and partially GreB can in fact complement these requirements under certain conditions. Here, we wished to investigate a broader effect of GreA and GreB on ppGpp0 and ppGpp0 dksA- strains. Since the parent strains are unable to grow in minimal media, we had to supplement the M9 glucose medium with a set of amino acids (DFHILQSTV). We found that both, GreA and GreB can affect a much larger set of genes in the absence of dksA, than in its presence. Also, GreA seems to affect more genes than GreB, under both conditions. We used microarrays to detail the effects of overproducing either GreA or GreB in cells devoid of ppGpp, in the dksA+ or dksA- background E. coli cells harbouring plasmids carrying either greA (pA = pHM1873) or greB (pB = pHM1874) genes, or vector control (pGB2), were monitored in an effort to elucidate the effects of their protein products. This was done in two backgrounds- either in E. coli ppGpp0 cells (ΔrelA, ΔspoT) carrying wt dksA gene or a dksA deletion.
2011-10-26 | E-GEOD-28795 | biostudies-arrayexpress