PilY1 and minor pilins form a complex priming the type IVa pilus in Myxococcus xanthus
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q Exactive
ORGANISM(S): Myxococcus Xanthus Dk 1622
SUBMITTER: 
Timo Glatter
LAB HEAD: Timo Glatter
PROVIDER: PXD021163 | Pride | 2020-09-02
REPOSITORIES: Pride
Similar Datasets
Project description:Type IVa pili (T4aP) are versatile bacterial cell surface structures that undergo extension/adhesion/retraction cycles powered by the cell envelope-spanning T4aP machine. In this machine, a complex composed of four minor pilins and PilY1 primes T4aP extension and is also present at the pilus tip mediating adhesion. Similar to many other bacteria, Myxococcus xanthus contains multiple minor pilins/PilY1 sets, the function of which remains unknown.Here, we report that minor pilins and PilY1 of cluster_1 (PilY1.1) form calcium-responsive priming and tip complexes contingent on a non-canonical cytochrome c (TfcP) with an unusual His/Cys heme ligation. We provide evidence that TfcP is unlikely to participate in electron transport and has been repurposed to promote calcium binding by PilY1.1 at low calcium concentrations, thereby stabilising PilY1.1 and enabling its function in a broader range of calcium concentrations. These results identify a novel function of cytochromes c and illustrate how incorporating an accessory factor expands the environmental range under which the T4aP system functions.
2022-01-30 | PXD031263 | Pride
Project description:Type IVa pili (T4aP) are versatile bacterial cell surface structures that undergo extension/adhesion/retraction cycles powered by the cell envelope-spanning T4aP machine. In this machine, a complex composed of four minor pilins and PilY1 primes T4aP extension and is also present at the pilus tip mediating adhesion. Similar to many other bacteria, Myxococcus xanthus contains multiple minor pilins/PilY1 sets, the function of which remains unknown.Here, we report that minor pilins and PilY1 of cluster_1 (PilY1.1) form calcium-responsive priming and tip complexes contingent on a non-canonical cytochrome c (TfcP) with an unusual His/Cys heme ligation. We provide evidence that TfcP is unlikely to participate in electron transport and has been repurposed to promote calcium binding by PilY1.1 at low calcium concentrations, thereby stabilising PilY1.1 and enabling its function in a broader range of calcium concentrations. These results identify a novel function of cytochromes c and illustrate how incorporating an accessory factor expands the environmental range under which the T4aP system functions.
2022-01-30 | PXD031267 | Pride
Project description:Type IV pili (T4P) are prevalent, polymeric surface structures in pathogenic bacteria, making them ideal targets for effective vaccines. However, bacteria have evolved efficient strategies to evade type IV pili-directed antibody responses. Neisseria meningitidis are prototypical type IV pili-expressing Gram-negative bacteria responsible for life threatening sepsis and meningitis. This species has evolved several genetic strategies to modify the surface of its type IV pili based on recombination, phase variation and the presence of different alleles of genes involved in posttranslational modifications. This results in changes in pilin subunit amino acid sequence, nature of glycosylation and phosphoform modification, but how these different processes affect antibody binding at the structural level is still unknown. To explore this question, we provide cryo-electron microscopy structures of pili of different sequence types with sufficiently high resolution to visualize posttranslational modifications. We then generated nanobodies directed against type IV pili which alter pilus function in vitro and vivo; and determined their structures complexed with their pilus target. We also determined how the different types of pili surface modifications alter nanobody binding. These different structures shed light on the impressive complementarity between the different strategies used by bacteria to avoid antibody binding. Importantly, we also show that structural information can be used to make informed modifications in nanobodies as countermeasures to these immune evasion mechanisms.
2024-02-29 | PXD046119 | Pride
Project description:The ATPase protein PilT mediates retraction of type IV pili. We performed microarrays comparing the transcription profile of the Neisseria gonorrhoeae wild-type strain MS11 and its isogenic pilT mutant. 63 open reading frames were found to be differentially regulated in the pilT mutant. Most interestingly, a loss of function mutation in pilT leads to an upregulation of pilE, which encodes the pilus subunit protein.
2008-09-01 | GSE12258 | GEO
Project description:Group A Streptococcus (GAS) is one of the world’s most successful pathogens, causing a multitude of common infections such as pharyngitis, cellulitis, and impetigo. It is also responsible for more severe diseases such as rheumatic fever, necrotizing fasciitis, and toxic shock syndrome. Group A Streptococcus produces a powerful peptide toxin known as streptolysin S (SLS). Although recent advances have begun to uncover the structure of SLS, many questions remain as to its route of synthesis, export and function. A fundamental yet unanswered question about SLS is the mechanism employed by GAS to resist the effects of its own toxin. To address this question, we developed a unique microarray-based approach aimed at identifying bacterial genes involved in SLS immunity. We measured changes in gene expression in a non-SLS producing GAS strain (∆SLS) after exposure to active SLS, as well as to an inactive SLS isoform. Initial exposure of a non-SLS producing GAS to the native SLS toxin resulted in significant upregulation of several gene candidates. Proteins encoded by these gene candidates were produced and tested for their ability to neutralize SLS toxin activity in vitro. The protein encoded by the gene Spy_0787 decreased the cytolytic activity of wt SLS by 50%. Bacterial immunity is still a relatively unknown and unexplained phenomena. Insights into how toxin-producing microorganisms achieve resistance against the effects of their own toxin could uncover important therapeutic targets to neutralize virulence factors such as SLS, as well as other related peptide toxins. The microarray technique described here can be leveraged to other microbial systems to understand how microorganisms in general react to antibacterial and cytotoxic compounds for which the mechanism of action is unknown. Supernatants containing wt and S39A forms of SLS secreted by GAS strains were collected from 50 ml of overnight cultures of each strain at 37 degrees C in Todd Hewett broth supplemented with 10 mg/ml of bovine serum albumin fraction V (Sigma chemicals) in order to stabilize the toxin. The supernatant was then isolated and subjected to filter sterilization. For SLS exposure conditions, bacterial pellets containing GAS ∆SagA mutants were incubated with 1. supernatants containing wtSLS; 2. supernatants containing SLS S39A isoform; or 3. sterile TH media with 10mg/ml of BSA. The bacteria pellets were quickly resuspended after which the bacterial pellets were recollected for RNA isolation. A total of three exposure timepoints were used: 0h (immediately after exposure to SLS-containing supernatants), 3h post-exposure, and 6h post-exposure. The pellets were frozen at -80C until used for RNA extraction. Total RNA extraction and purification from the bacterial pellets were performed using the RNeasy isolation kit per manufacturer's instructions (Qiagen). RNA samples were processed following standard Roche NimbleGen gene expression analysis protocols. Double-stranded cDNA was synthesized from 10 μg of total RNA using random hexamer primers with the SuperScript cDNA synthesis kit (Invitrogen). One μg of cDNA was labeled with Cy3-random nonamers (Roche NimbleGen) for microarray hybridization.
2013-09-01 | E-GEOD-48775 | biostudies-arrayexpress
Project description:The pilus retraction protein PilT has a global influence on the transcriptome of Neisseria gonorrhoeae
| PRJNA113637 | ENA
Project description:Early multiple sclerosis lesions feature relative preservation of oligodendrocyte cell bodies with dying back retraction of their myelinating processes. Cell loss occurs with disease progression. Putative injury mediators include metabolic stress (low glucose/nutrient), pro-inflammatory mediators (interferon γ and tumor necrosis factor a), and excitotoxins (glutamate). Our objective was to compare the impact of these disease relevant mediators on the injury responses of human mature oligodendrocytes. In the current study, we determined the effects of these mediators on process extension and survival of human brain derived mature oligodendrocytes in vitro and used bulk RNA sequencing to identify distinct effector mechanisms that underlie the responses. All mediators induced significant process retraction of the oligodendrocytes in dissociated cell culture. Only metabolic stress (low glucose/nutrient) conditions resulted in delayed (4-6 days) non-apoptotic cell death. Metabolic effects were associated with induction of the integrated stress response, which can be protective or contribute to cell injury dependent on its level and duration of activation. Addition of Sephin1, an agonist of the integrated stress response induced process retraction under control conditions and further enhanced retraction under metabolic stress conditions. The antagonist ISRIB restored process outgrowth under stress conditions, and if added to already stressed cells, reduced delayed cell death and prolonged the period in which recovery could occur. Inflammatory cytokine functional effects were associated with activation of multiple signaling pathways (including Jak/Stat-1) that regulate process outgrowth, without integrated stress response induction. Glutamate application produced limited transcriptional changes suggesting a contribution of effects directly on cell processes.
2023-12-08 | GSE249381 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE3101: Chitin oligosaccharide induction GSE3102: Crab shell attachment GSE3103: Chitin sensor Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin. Refer to individual Series
2006-03-07 | E-GEOD-4388 | biostudies-arrayexpress
Project description:The ATPase protein PilT mediates retraction of type IV pili. We performed microarrays comparing the transcription profile of the Neisseria gonorrhoeae wild-type strain MS11 and its isogenic pilT mutant. 63 open reading frames were found to be differentially regulated in the pilT mutant. Most interestingly, a loss of function mutation in pilT leads to an upregulation of pilE, which encodes the pilus subunit protein. Ngo arrays were generated as custom 8x15 K microarrays (Agilent Technologies) covering all open reading frames (ORFs) from N. gonorrhoeae strain FA1090 (accession number AE004969) supplemented with all ORFs from the gonoccoccal genetic island of strain MS11 (accession number AY803022) by 6 specific 60-mer oligonucleotides per gene on average. Microarray analysis was performed as dual-color hybridization with dye-reversal color-swaps as technical replicates for Cy-dye specific effect compensation and three independent biological replicates. Microarray features were extracted with the FE 9.5.3.1 software from Agilent Technologies using the GE2-v4_95_Feb07 protocol with default settings. Data were loaded into Resolver (Rosetta Biosoftware) using the MAGE-ML loader and analyzed for differential gene expression. Ratio profiles were combined into ratio experiments and regulated genes were identified with a threshold of 1.75 fold-change and anti-correlation of the color-swapped dye reversals, rendering the analysis highly stringent and robust with P values <0.0001 of the results.
2008-09-01 | E-GEOD-12258 | biostudies-arrayexpress
Project description:Rationale: We recently demonstrated that the triple combination CFTR modulator therapy elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) improves lung ventilation and airway mucus plugging determined by multiple-breath washout and magnetic resonance imaging in CF patients with at least one F508del allele. However, effects of ELX/TEZ/IVA on viscoelastic properties of airway mucus, chronic airway infection and inflammation have not been studied. Objectives: To examine the effects of ELX/TEZ/IVA on airway mucus rheology, microbiome and inflammation in CF patients with one or two F508del alleles aged 12 years and older. Methods: In this prospective observational study, we determined sputum rheology, microbiome, inflammation markers and proteome before and 1, 3 and 12 months after initiation of ELX/TEZ/IVA. Measurements and Main Results: CF patients with at least one F508del allele and healthy controls were enrolled in this study. ELX/TEZ/IVA improved the elastic and viscous modulus of CF sputum. Further, ELX/TEZ/IVA improved the microbiome α-diversity and decreased the relative abundance of Pseudomonas aeruginosa (P<0.05) in CF sputum. ELX/TEZ/IVA also reduced IL-8 and free NE activity, and shifted the CF sputum proteome towards healthy. Conclusions: Our data demonstrate that ELX/TEZ/IVA improves sputum viscoelastic properties, chronic airway infection and inflammation in CF patients with at least one F508del allele, however, without reaching levels close to healthy.
2023-06-22 | PXD041844 | Pride