BP2265 is a chaperone of T3SS anti-sigma factor BtrA in Bordetella pertussis
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PROVIDER: PRJEB65304 | ENA |
REPOSITORIES: ENA
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Project description:Bordetella pertussis is a Gram-negative, strictly human respiratory pathogen and the causative agent of whooping cough (pertussis). Similar to other Gram-negative pathogens, B. pertussis produces a functional type III secretion system, but its role in pathogenesis of B. pertussis is enigmatic and has not yet been elucidated. Here, we applied omics RNA-seq as well as LC-MS/MS techniques and co-immunoprecipitation method to identify and characterize the novel CesT family T3SS chaperone BP2265. Our results show that the chaperone BP2265 specifically interacts with the secreted T3SS anti-sigma factor BtrA. Moreover, in the absence of the chaperone, secretion but not production of BtrA and several early, intermediate, and late T3SS substrates is severely impaired. It appears that the role of BtrA in regulating T3SS is more complex and extends beyond its activity as an antagonist of the sigma factor BtrS. We propose to rename BP2265 as BtcB for the Bordetella type III chaperone of BtrA.
2024-01-26 | PXD044487 | Pride
Project description:Bordetella pertussis is a human pathogen that can infect the respiratory tract and cause the disease known as whooping cough. B. pertussis uses pertussis toxin (PT) and adenylate cyclase toxin (ACT) to kill and modulate host cells to allow the pathogen to survive and persist. B. pertussis encodes many uncharacterized transcription factors, and very little is known about their functions. RpoE is a sigma factor which, in other bacteria, responds to oxidative, heat, and other environmental stresses. RseA is a negative regulator of RpoE that sequesters the sigma factor to regulate gene expression based on conditions. In B. pertussis, deletion of the rseA gene results in high transcriptional activity of RpoE and large amounts of secretion of ACT. By comparing parental B. pertussis to an rseA gene deletion mutant (PM18), we sought to characterize the roles of RpoE in virulence and determine the regulon of genes controlled by RpoE. Despite high expression of ACT, the rseA mutant strain did not infect the murine airway as efficiently as the parental strain and PM18 was killed more readily when inside phagocytes. RNA sequencing analysis was performed and 263 genes were differentially regulated by RpoE, and surprisingly, the rseA mutant strain where RpoE activity was elevated expressed very little pertussis toxin. Western blots and proteomic analysis corroborated the inverse relationship of PT to ACT expression in the high-RpoE-activity rseA deletion strain. Our data suggest that RpoE can modulate PT and ACT expression indirectly through unidentified mechanisms in response to conditions.
| S-EPMC5203664 | biostudies-literature
Project description: Not available
| S-EPMC4097619 | biostudies-literature
Project description:The BvgAS phosphorelay regulates ?10% of the annotated genomes of Bordetella pertussis and Bordetella bronchiseptica and controls their infectious cycles. The hierarchical organization of the regulatory network allows the integration of contextual signals to control all or specific subsets of BvgAS-regulated genes. Here, we characterize a regulatory node involving a type III secretion system (T3SS)-exported protein, BtrA, and demonstrate its role in determining fundamental differences in T3SS phenotypes among Bordetella species. We show that BtrA binds and antagonizes BtrS, a BvgAS-regulated extracytoplasmic function (ECF) sigma factor, to couple the secretory activity of the T3SS apparatus to gene expression. In B. bronchiseptica, a remarkable spectrum of expression states can be resolved by manipulating btrA, encompassing over 80 BtrA-activated loci that include genes encoding toxins, adhesins, and other cell surface proteins, and over 200 BtrA-repressed genes that encode T3SS apparatus components, secretion substrates, the BteA effector, and numerous additional factors. In B. pertussis, BtrA retains activity as a BtrS antagonist and exerts tight negative control over T3SS genes. Most importantly, deletion of btrA in B. pertussis revealed T3SS-mediated, BteA-dependent cytotoxicity, which had previously eluded detection. This effect was observed in laboratory strains and in clinical isolates from a recent California pertussis epidemic. We propose that the BtrA-BtrS regulatory node determines subspecies-specific differences in T3SS expression among Bordetella species and that B. pertussis is capable of expressing a full range of T3SS-dependent phenotypes in the presence of appropriate contextual cues.
| S-EPMC4780644 | biostudies-literature
Project description:Using TurboID to study the proxisome of Shigella flexneri's Type 3 Secretion System (T3SS) chaperone IpgC, and transcriptional activator MxiE. The proxisome was studied in the ON (active secretion) and OFF (inactive secretion) states of the T3SS using N and C -terminal fusions of TurboID to the baits IpgC and MxiE.
2024-07-29 | MSV000095473 | MassIVE
Project description:Copper is both essential and toxic to living beings, which therefore tightly control its intracellular concentration. At the host-pathogen interface, copper is used by phagocytic cells to kill invading microorganisms. We investigated copper homeostasis in the whooping cough agent Bordetella pertussis, which lives in the human respiratory mucosa and has no environmental reservoir. B. pertussis has considerably streamlined copper homeostasis mechanisms relative to other Gram-negative bacteria. Its single remaining defense line against copper intoxication consists in a metallochaperone diverted for copper passivation and two enzymes involved in peroxide detoxification, which together fight two stresses encountered in phagolysosomes. The three proteins are encoded by an original, composite operon assembled in an environmental ancestor and which is under sensitive control by copper. Interestingly, this system appears to play a role in persistent infection in the nasal cavity of B. pertussis-infected mice. Combining responses to co-occurring stresses in a tailored operon reveals a new strategy adopted by a host-restricted pathogen to optimize survival at minimal energy expenditure.
2020-10-27 | GSE145049 | GEO
Project description:Bordetella pertussis, the etiological agent of whooping cough, regulates the expression of its virulence factors by the well-defined BvgA/S two-component regulatory system. Phosphorylated BvgA activates the virulence activated genes (vags) and represses via the activation of the bvgR gene the expression of the virulence repressed genes (vrgs). In the presence of MgSO4, known as modulating condition, the BvgA/S system is inactive, and the vrgs are expressed. Here, we show that, except for 6 genes of unknown function, the expression of all the vrgs depends on RisA, another transcriptional two-component regulator. In addition to the vrgs, RisA also regulates the expression of a many other genes. Whereas the expression of most vags was not affected by the deletion of risA, some vags, including the genes coding for pertactin, filamentous hemagglutinin, fimbriae and adenylate cyclase toxin, were surprisingly no longer modulated by MgSO4 in the risA- background. Yet another set of genes, mostly of unknown function, were modulated only in the risA- background. Finally, a large group of genes were up-regulated under modulating conditions only in the risA- background. They comprise genes of the chemotaxis and flagellar operons, iron-regulated genes, some of which are under the control of BvgA/S, while others are not. We identified RisK as the cognate RisA kinase, and found that most of the RisA-dependent genes also required RisK for expression, whereas a few genes were independent of RisK. These results were confirmed by the replacement of RisA with the phosphoablative RisAD60N analog and the phosphomimetic RisAD60E analog. Thus, according to its phosphorylation state, RisA regulates the expression of many genes, which may or may not also be regulated by the BvgA/S system, adding a new layer of complexity of B. pertussis gene regulation.
2016-08-20 | GSE77754 | GEO
Project description:Bordetella pertussis, B. parapertussis, and B. bronchiseptica cause respiratory infections, many of which are characterized by coughing of the infected hosts. The pathogenesis of the coughing remains to be analyzed, mainly because there were no convenient infection models of small animals that replicate coughing after Bordetella infection. Here, we present a coughing model of rats infected with B. bronchiseptica Rats, which are one of natural hosts of B. bronchiseptica, were readily infected with the organisms and showed frequent coughing. B. pertussis also caused coughing in rats, which is consistent with previous reports, but the cough response was less apparent than the B. bronchiseptica-induced cough. By using the rat model, we demonstrated that adenylate cyclase toxin, dermonecrotic toxin, and the type III secretion system are not involved in cough production, but BspR/BtrA (different names for the same protein), an anti-σ factor, regulates the production of unknown factor(s) to cause coughing. Rat coughing was observed by inoculation of not only the living bacteria but also the bacterial lysates. Infection with bspR (btrA)-deficient strains caused significantly less frequent coughing than the wild type; however, intranasal inoculation of the lysates from a bspR (btrA)-deficient strain caused coughing similarly to the wild type, suggesting that BspR/BtrA regulates the production of the cough factor(s) only when the bacteria colonize host bodies. Moreover, the cough factor(s) was found to be heat labile and produced by B. bronchiseptica in the Bvg+ phase. We consider that our rat model provides insight into the pathogenesis of cough induced by the Bordetella infection.IMPORTANCE Whooping cough is a contagious respiratory disease caused by Bordetella pertussis This disease is characterized by severe paroxysmal coughing, which becomes a heavy burden for patients and occasionally results in death; however, its pathogenesis remains largely unknown. The major obstacle to analyzing Bordetella-induced coughing is the lack of conventional animal models that replicate coughing. As Bordetella pertussis is highly adapted to humans, infection models in experimental animals are not considered to be well established. In the present study, we examined coughing in rats infected with B. bronchiseptica, which shares many virulence factors with B. pertussis Using this rat model, we demonstrated that some of the major virulence factors of Bordetella are not involved in cough production, but an anti-σ factor, BspR/BtrA, of B. bronchiseptica regulates the production of unknown cough-causing bacterial factor(s). Our results provide important clues to understand the mechanism by which Bordetella induces cough.
| S-EPMC6483047 | biostudies-literature
Project description:We examined the BvgA fixation on the genome of B. pertussis in different strains and culture conditions
2020-05-01 | GSE137027 | GEO
Project description:Purpose: Within the past 20 years, outbreaks of whooping cough, caused by Bordetella pertussis, have led to respiratory disease and infant mortalities, despite good vaccination coverage. This is due at least in part to the introduction of a less effective acellular vaccine in the 1990’s. It is crucial then to understand the molecular basis of B. pertussis growth and infection. The two-component system BvgA/BvgS is the B. pertussis master regulator that regulates the expression of various virulence genes. Previous genome wide studies to identify the bvgAS regulon in B. pertussis have been limited to microarray analyses. The goal of this study is to define the bvgAS regulon using NGS based RNA-seq analysis and RT-qPCR and to compare the differences with the previous microarray data. Method: To define the bvgAS regulon, transcriptomes were generated using B. pertussis Tohama I BP536 (WT) and a ΔbvgAS derivative in the presence and absence of phosphorylated BvgA. Bacteria were grown either under modulating (50 mM MgSO4) conditions, in which phosphorylated BvgA is undetectable (Bvg- mode), or non-modulating (no MgSO4) conditions in which BvgA is phosphorylated (Bvg+ mode). After total RNA extraction and rRNA removal, strand-specific DNA libraries were prepared for Illumina sequencing using the ScriptSeq 2.0 kit (Illumina) in duplicates. Libraries were sequenced using a HiSeq 2000 sequencer (Illumina; University of Buffalo Next Generation Sequencing Core Facility). Sequence reads were mapped to the reference genome (NC_002929.2) and normalized against total reads. Differential expression analyses were performed using CLC Biomedical Genomic Workbench version 3.5.4 with default parameters. Differential gene expression profiles were obtained after Empirical DGE statistical test with FDR p-value. RT–qPCR validation was performed using SYBR Green assays. Result: Using CLC Biomedical Genomic Workbench version 3.5.4, ~ 20-25 million reads per sample were mapped to the reference B. pertussis genome (NC_002929.2). RNA-seq analyses identified >550 genes (15% of genome) that were regulated in a bvgAS-dependent manner with a fold difference ≥ 1.6 and FDR p-value < 0.05. RT-qPCR was used for confirmatory analyses for 80 genes. Overall, we identified 245 genes that were positively regulated and 326 genes that were negatively regulated by bvgAS. 362 members of the bvgAS regulon were newly identified by our study. Most importantly, our analyses indicated that the expression of dozens of transcriptional regulators increases, while the expression of multiple metabolic genes decreases in the presence of BvgA~P. Conclusion: We report here the first RNA-seq analysis of the bvgAS regulon in B. pertussis, revealing that > 550 genes are regulated by bvgAS. Our results suggest that metabolic changes in the Bvg- mode (absence of BvgA phosphorylation) may be participating in bacterial survival, transmission, and/or persistence and identify over 200 new genes negatively regulated by bvgAS that can be tested for function.
2017-09-22 | GSE98155 | GEO