S. aureus exoproteome in the context of genetic competence development
Ontology highlight
ABSTRACT:
INSTRUMENT(S): timsTOF Pro
ORGANISM(S): Staphylococcus Aureus
TISSUE(S): Cell Suspension Culture
SUBMITTER: 
David Cornu
LAB HEAD: David Cornu
PROVIDER: PXD040550 | Pride | 2023-04-26
REPOSITORIES: Pride
Similar Datasets
Project description:Lactococcus lactis is one of the most important lactic acid bacterium used in the dairy industry. Activation of natural DNA transformation in this species would greatly improve the selection of novel strains with desired industrial traits. Here, we investigate the activation of natural transformation in L. lactis ssp. cremoris KW2, a strain of plant origin whose genome encodes the master competence regulator ComX and the complete set of essential late gene products required for natural transformation under its potential control. In absence of any information on the competence signaling system in this species, activation of natural DNA transformation by the constitutive production of ComX was attempted. Using a reporter strain of late competence phase activation and transcriptomic analyses, we show that all key genes for natural transformation can be induced in strain KW2. Then, we demonstrate that natural DNA transformation is functional in this strain and that this process requires the DNA uptake machinery dedicated to competence. Various chromosomal modifications such as point mutations or gene deletion/insertion could be quickly and efficiently achieved. These results are the first to report the functionality of natural DNA transformation in L. lactis and pave the way for the identification of molecular mechanisms activating competence development in this species.
2017-06-29 | GSE86476 | GEO
Project description:In marine Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome via homologous recombination. Expression of the master competence regulator TfoX bypasses the need for chitin induction and drives expression of the genes required for competence in several Vibrio species. Here, we show that TfoX expression in two Vibrio campbellii strains, DS40M4 and NBRC 15631, enables high frequencies of natural transformation. Conversely, transformation was not achieved in the model quorum-sensing strain V. campbellii BB120 (previously classified as Vibrio harveyi). Surprisingly, we find that quorum sensing is not required for transformation in V. campbellii DS40M4. This result is in contrast to Vibrio cholerae that requires the quorum-sensing regulator HapR to activate the competence regulator QstR. However, similar to V. cholerae, QstR is necessary for transformation in DS40M4. To investigate the difference in transformation frequencies between BB120 and DS40M4, we used previously studied V. cholerae competence genes to inform a comparative genomics analysis coupled with transcriptomics. BB120 encodes homologs of all known competence genes, but most of these genes were not induced by ectopic expression of TfoX, which likely accounts for the non-functional natural transformation in this strain. Comparison of transformation frequencies among Vibrio species indicates a wide disparity among even closely related strains, with Vibrio vulnificus having the lowest functional transformation frequency. We show that ectopic expression of both TfoX and QstR is sufficient to produce a significant increase in transformation frequency in Vibrio vulnificus.
2019-11-14 | GSE136941 | GEO
Project description:Here we demonstrate by experimental evolution and genetics the rapid and repeatable evolutionary re-wiring of regulatory pathways, where the cellular nitrogen regulatory system acquired the ability to “cross-talk” with the flagellar regulon. This rewiring restored flagella to aflagellate strains of Pseudomonas fluorescens devoid of the master regulator fleQ via a repeatable two-step evolutionary pathway. Step 1 initiates cross-talk by increasing intracellular levels of phosphorylated NtrC , a distant homologue of FleQ, which begins to commandeer control of the fleQ regulon whilst constitutively activating nitrogen uptake and assimilation genes. Step 2 is a switch-of-function mutation (NtrC’) that further redirects NtrC towards activation of motility and away from nitrogen uptake. Evolved NtrC’ emerges with a novel function as a flagellar regulator. Our results demonstrate that natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps to adopt new functionality.
2015-07-04 | E-MTAB-2788 | biostudies-arrayexpress
Project description:Pathogens that grow during infections must cope with the reactive oxygen species (ROS) released by host immune cells. Among the different strategies to prevent oxidative damage during infections, pathogenic bacteria have evolved mechanisms to reduce respiration and other cellular processes that are particularly sensitive to free radicals, obtaining energy preferentially by undergoing to fermentative metabolism. As fermentation produces fewer ATP per glucose than respiration, bacteria ensure an appropriate supply of energy by increasing the glycolytic flux. The opportunistic human pathogen Staphylococcus aureus is one such microbe but the underlying mechanism that enables S. aureus to induce fermentation during infections is still unclear. Here we show that the ComK-like regulator of natural competence that is present in many gram-positive bacteria is crucial to redirect S. aureus metabolism to fermentation during infection. ComK is cryptic in laboratory conditions but highly induced during infections or in response to infection-related cues, such as ROS. ComK induces the glycolytic flux and glucose consumption rate, a key step to redirect ATP production to fermentation. This licenses fermenting S. aureus to reduce oxidative damage while increasing DNA uptake by natural transformation. As a consequence, a comK-defective mutant shows an accumulation of ROS as well as DNA mutations that lower bacterial survival. This mutant shows no distinctive phenotype in laboratory conditions but is unable to cause infection in vertebrates or invertebrate infection models. ComK-mediated synchronization of natural transformation to fermentative metabolism may allow S. aureus, and probably other gram-positive bacteria, to use the fermentation acid end products to eliminate bacterial competitors while assimilating their DNA. Assimilated DNA may serve as a source of nucleotides for DNA repair or to promote genetic variability, thereby enabling a successful host colonization of this bacterium.
2022-02-26 | GSE155016 | GEO
Project description:Small distortions in transcriptional networks might lead to drastic phenotypical changes, especially in cellular developmental programs such as competence for natural transformation. Here, we report a pervasive circuitry rewiring for competence and predation interplay in commensal streptococci. Canonically, in model species of streptococci such as Streptococcus pneumoniae and Streptococcus mutans, the pheromone-based two-component system BlpRH is a central node that orchestrates the production of antimicrobial compounds (bacteriocins) and incorporates signal from the competence activation cascade. However, the human commensal Streptococcus salivarius does not contain a functional BlpRH pair and in this species, the competence signaling system ComRS directly couples bacteriocin production and competence commitment. This network shortcut might account for an optimal reaction against microbial competitors and could explain the high prevalence of S. salivarius in the human digestive tract. Moreover, the broad spectrum of bacteriocin activity against pathogenic bacteria showcases the commensal and genetically tractable S. salivarius species as a user-friendly model for natural transformation and bacterial predation.
2018-01-10 | GSE100416 | GEO
Project description:We applied a novel negative selection strategy called genomic array footprinting (GAF) to identify genes required for genetic transformation of the gram-positive bacterium Streptococcus pneumoniae. Genome-wide mariner-transposon mutant libraries in S. pneumoniae strain R6 were challenged by transformation with an antibiotic resistance cassette and growth in the presence of the corresponding antibiotic. The GAF screen identified the enrichment of mutants in two genes, i.e., hexA and hexB, and the counter-selection of mutants in 21 different genes during the challenge. Eight of the counter-selected genes were known to be essential for pneumococcal transformation. Four other genes, i.e., radA, comGF, parB, and spr2011, have previously been linked to the competence regulon, and one, spr2014, was located adjacent to the essential competence gene comFA. Directed mutants in which seven of the eight remaining genes, i.e., spr0459/spr0460, spr0777, spr0838, spr1259/spr1260, and spr1357, were deleted, displayed reduced, albeit modest, transformation rates. No connection to pneumococcal transformation could be made for the eighth gene, which encodes the response regulator RR03. We further demonstrated that the gene encoding the putative DNA repair protein RadA is required for efficient transformation of chromosomal markers, whereas transformation with replicating plasmid DNA was not significantly affected. The radA mutant also displayed an increased sensitivity to treatment with the DNA-damaging agent methyl methanesulfonate. Hence, RadA is considered to have a role in recombination of donor DNA and DNA damage repair in S. pneumoniae. Keywords: GAF competence Selection for genes essential for transformation. Aliquots of a marinerT7 transposon library generated in S. pneumoniae R6 containing approximately 40,000 independent mutants were transformed with an antibiotic resistance marker and grown without (initial library) or with (challenged library) antibiotics for 25 generation until DNA extraction.
2007-09-04 | E-GEOD-8362 | biostudies-arrayexpress
Project description:We applied a novel negative selection strategy called genomic array footprinting (GAF) to identify genes required for genetic transformation of the gram-positive bacterium Streptococcus pneumoniae. Genome-wide mariner-transposon mutant libraries in S. pneumoniae strain R6 were challenged by transformation with an antibiotic resistance cassette and growth in the presence of the corresponding antibiotic. The GAF screen identified the enrichment of mutants in two genes, i.e., hexA and hexB, and the counter-selection of mutants in 21 different genes during the challenge. Eight of the counter-selected genes were known to be essential for pneumococcal transformation. Four other genes, i.e., radA, comGF, parB, and spr2011, have previously been linked to the competence regulon, and one, spr2014, was located adjacent to the essential competence gene comFA. Directed mutants in which seven of the eight remaining genes, i.e., spr0459/spr0460, spr0777, spr0838, spr1259/spr1260, and spr1357, were deleted, displayed reduced, albeit modest, transformation rates. No connection to pneumococcal transformation could be made for the eighth gene, which encodes the response regulator RR03. We further demonstrated that the gene encoding the putative DNA repair protein RadA is required for efficient transformation of chromosomal markers, whereas transformation with replicating plasmid DNA was not significantly affected. The radA mutant also displayed an increased sensitivity to treatment with the DNA-damaging agent methyl methanesulfonate. Hence, RadA is considered to have a role in recombination of donor DNA and DNA damage repair in S. pneumoniae. Keywords: GAF competence
2007-09-05 | GSE8362 | GEO
Project description:The gastric human pathogen Helicobacter pylori has developed mechanisms to combat stress factors, including reactive oxygen species (ROS). Here, we present a comprehensive study on the redox switch protein HP1021 regulon combining transcriptomic, proteomic and DNA-protein interactions analyses. Our results indicated that HP1021 modulates H. pylori's response to oxidative stress. HP1021 controlled the transcription of 497 genes, including 407 genes related to response to oxidative stress. 79 proteins were differently expressed in the HP1021 deletion mutant. HP1021 regulated typical ROS response pathways (katA, rocF) and less canonical ones, particularly DNA uptake and central carbohydrate metabolism. We identified HP1021 as the first molecular regulator of competence in H. pylori, as HP1021-dependent repression of the comB DNA uptake genes was relieved under oxidative conditions, increasing natural competence. Furthermore, HP1021 controlled glucose consumption by directly regulating the gluP transporter and had an important impact on maintaining the energetic balance in the cell.
2023-09-20 | PXD041978 | Pride
Project description:A ubiquitous and versatile anaerobic saprophite with natural transformation competence, opportunistic nosocomial pathogen.
| PRJNA12352 | ENA
Project description:As a sextual behavior, competence or natural transformation mediates lateral gene transfer, and thereby promotes exchange of antibiotic resistance and virulence traits among bacteria. Competence is assoicated with activation of many genes, rapid build-up of membrane-bound DNA uptake apparatus, and transient growth arrest. It is completely unknown how transformable bacteria recover from the competence-associated status. This work reveals that the membrane-associated HtrA protease enables the pneumococcus (an important human pathogen) to recover from the competence-associated status by breaking down the DNA uptake apparatus. This is achieved by selective degradation of ComEA and ComEC, the major components of the DNA uptake apparatus. Deleting htrA and/or over-expressing comEA-EC led to dramatic delay in competence termination. Based on high conservation of HtrA and DNA uptake proteins among transformable bacterial, the HtrA protease may serve as a general regulator of bacteria recovery from the competence-associated status.
2018-03-22 | GSE112169 | GEO