Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Streptococcus pyogenes Escapes Killing from Extracellular Histones through Plasminogen Binding and Activation by Streptokinase.

ABSTRACT: Histones are small basic proteins and highly conserved among eukaryotes. Their main function is binding, packaging and organizing of DNA in the nucleus, but extracellular histones are also potent antimicrobial proteins. Here we found that Streptococcus pyogenes - an important human pathogen - protects itself from histone-killing by the acquisition of plasminogen. Plasminogen, bound to the streptococcal surface, efficiently prevents histone-mediated killing. Moreover, the streptokinase/plasminogen complex degrades all classes of histones and abrogates their antibacterial and hemolytic effects. This novel streptokinase-mediated virulence mechanism may contribute to the escape of S. pyogenes from the human innate immune system.

SUBMITTER: Nitzsche R

PROVIDER: S-EPMC6738899 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Streptococcus pyogenes Escapes Killing from Extracellular Histones through Plasminogen Binding and Activation by Streptokinase.

Nitzsche Ramona R Köhler Juliane J Kreikemeyer Bernd B Oehmcke-Hecht Sonja S

Journal of innate immunity 20160818 6

Histones are small basic proteins and highly conserved among eukaryotes. Their main function is binding, packaging and organizing of DNA in the nucleus, but extracellular histones are also potent antimicrobial proteins. Here we found that Streptococcus pyogenes - an important human pathogen - protects itself from histone-killing by the acquisition of plasminogen. Plasminogen, bound to the streptococcal surface, efficiently prevents histone-mediated killing. Moreover, the streptokinase/plasminoge ...[more]

PMID: 27533300

Similar Datasets

Streptococcus pyogenes M49 plasminogen/plasmin binding facilitates keratinocyte invasion via integrin-integrin-linked kinase (ILK) pathways and protects from macrophage killing.

Project description:The entry into epithelial cells and the prevention of primary immune responses are a prerequisite for a successful colonization and subsequent infection of the human host by Streptococcus pyogenes (group A streptococci, GAS). Here, we demonstrate that interaction of GAS with plasminogen promotes an integrin-mediated internalization of the bacteria into keratinocytes, which is independent from the serine protease activity of potentially generated plasmin. ?(1)?(1)- and ?(5)?(1)-integrins were identified as the major keratinocyte receptors involved in this process. Inhibition of integrin-linked kinase (ILK) expression by siRNA silencing or blocking of PI3K and Akt with specific inhibitors, reduced the GAS M49-plasminogen/plasmin-mediated invasion of keratinocytes. In addition, blocking of actin polymerization significantly reduced GAS internalization into keratinocytes. Altogether, these results provide a first model of plasminogen-mediated GAS invasion into keratinocytes. Furthermore, we demonstrate that plasminogen binding protects the bacteria against macrophage killing.

| S-EPMC3122219 | biostudies-literature

Activity Regulation by Fibrinogen and Fibrin of Streptokinase from Streptococcus Pyogenes.

Project description:Streptokinase is a virulence factor of streptococci and acts as a plasminogen activator to generate the serine protease plasmin which promotes bacterial metastasis. Streptokinase isolated from group C streptococci has been used therapeutically as a thrombolytic agent for many years and its mechanism of action has been extensively studied. However, group A streptococci are associated with invasive and potentially fatal infections, but less detail is available on the mechanism of action of streptokinase from these bacteria. We have expressed recombinant streptokinase from a group C strain to investigate the therapeutic molecule (here termed rSK-H46A) and a molecule isolated from a cluster 2a strain from group A (rSK-M1GAS) which is known to produce the fibrinogen binding, M1 protein, and is associated with life-threatening disease. Detailed enzyme kinetic models have been prepared which show how fibrinogen-streptokinase-plasminogen complexes regulate plasmin generation, and also the effect of fibrin interactions. As is the case with rSK-H46A our data with rSK-M1GAS support a "trigger and bullet" mechanism requiring the initial formation of SK•plasminogen complexes which are replaced by more active SK•plasmin as plasmin becomes available. This model includes the important fibrinogen interactions that stimulate plasmin generation. In a fibrin matrix rSK-M1GAS has a 24 fold higher specific activity than the fibrin-specific thrombolytic agent, tissue plasminogen activator, and 15 fold higher specific activity than rSK-H46A. However, in vivo fibrin specificity would be undermined by fibrinogen stimulation. Given the observed importance of M1 surface receptors or released M1 protein to virulence of cluster 2a strain streptococci, studies on streptokinase activity regulation by fibrin and fibrinogen may provide additional routes to addressing bacterial invasion and infectious diseases.

| S-EPMC5268773 | biostudies-literature

Protein SIC Secreted from Streptococcus pyogenes Forms Complexes with Extracellular Histones That Boost Cytokine Production.

Project description:Innate immunity relies on an effective recognition of the pathogenic microorganism as well as on endogenous danger signals. While bacteria in concert with their secreted virulence factors can cause a number of inflammatory reactions, danger signals released at the site of infection may in addition determine the amplitude of such responses and influence the outcome of the disease. Here, we report that protein SIC, Streptococcal Inhibitor of Complement, an abundant secreted protein from Streptococcus pyogenes, binds to extracellular histones, a group of danger signals released during necrotizing tissue damage. This interaction leads to the formation of large aggregates in vitro. Extracellular histones and SIC are abundantly expressed and seen colocalized in biopsies from patients with necrotizing soft-tissue infections caused by S. pyogenes. In addition, binding of SIC to histones neutralized their antimicrobial activity. Likewise, the ability of histones to induce hemolysis was inhibited in the presence of SIC. However, when added to whole blood, SIC was not able to block the pro-inflammatory effect of histones. Instead SIC boosted the histone-triggered release of a broad range of cytokines and chemokines, including IL-6, TNF-α, IL-8, IL-1β, IL-1ra, G-CSF, and IFN-γ. These results demonstrate that the interaction between SIC and histones has multiple effects on the host response to S. pyogenes infection.

| S-EPMC5827136 | biostudies-literature

Structural diversity of streptokinase and activation of human plasminogen.

Project description:The beta domain of streptokinase is required for plasminogen activation and contains a region of sequence diversity associated with infection and disease in group A streptococci. We report that mutagenesis of this polymorphic region does not alter plasminogen activation, which suggests an alternative function for this molecular motif in streptococcal disease.

| S-EPMC1168554 | biostudies-literature

Regulation of streptokinase expression by CovR/S in Streptococcus pyogenes: CovR acts through a single high-affinity binding site.

Project description:The important human pathogen Streptococcus pyogenes (the group A streptococcus or GAS) produces many virulence factors that are regulated by the two-component signal transduction system CovRS (CsrRS). Dissemination of GAS infection originating at the skin has been shown to require production of streptokinase, whose transcription is repressed by CovR. In this work we have studied the interaction of CovR and phosphorylated CovR (CovR-P) with the promoter for streptokinase, Pska. We found that, in contrast to the other CovR-repressed promoters, Pska regulation by CovR occurs through binding at a single ATTARA consensus binding sequence (CB) that overlaps the -10 region of the promoter. Binding of CovR to other nearby consensus sequences occurs upon phosphorylation of the protein, but these other CBs do not contribute to the regulation of Pska by CovR. Thus, binding at a specific site does not necessarily indicate that the site is involved in regulation by CovR. In addition, at Pska, CovR binding to the different sites does not appear to involve cooperative interactions, which simplifies the analysis of CovR binding and gives us insight into the modes of interaction that occur between CovR and its specific DNA-binding sites. Finally, the observation that regulation of transcription from Pska occurs at a very low concentration of phosphorylated CovR may have important implications for the regulation of virulence gene expression during GAS infection.

| S-EPMC4130213 | biostudies-literature

Function of streptokinase fragments in plasminogen activation.

Project description:Several peptide fragments of streptokinase (SK) were prepared by incubating SK with immobilized human plasmin (hPlm) and purified by h.p.l.c. with a reverse-phase phenyl column. The N-terminal sequences, amino acid compositions and molecular masses of these peptide fragments were determined. The SK peptide fragment of 36 kDa consisting of Ser60-Lys387 (SK-p), was the only peptide fragment that could be tightly bound to immobilized hPlm. Another three large SK peptide fragments, SK-m, SK-n and SK-o, with molecular masses of 7 kDa, 18 kDa and 30 kDa, and consisting of Ile1-Lys59, Glu148-Lys333, Ser60-Lys333 respectively, were also obtained from the supernatant of the reaction mixture. The purified SK-p had high affinity with hPlm and could activate human plasminogen (hPlg) with a kPlg one-sixth that of the native SK. SK-o had low affinity with hPlm and could also activate hPlg, although the catalytic constant was less than 1% of the native SK. SK-n, as well as SK-m, which is the N-terminal 59 amino acid peptide of the native SK, had no activator activity. However, SK-m could enhance the activator activity of both SK-o and SK-p and increase their second-order rate constants by two- and six-fold respectively. It was concluded from these studies that (1) SK-o, the Ser60-Lys333 peptide of SK, was essential for minimal SK activator activity, (2) the C-terminal peptide of SK-p, Ala334-Lys387, was essential for high affinity with hPlm, and (3) the N-terminal 59-amino-acid peptide was important in maintaining the proper conformation of SK to have its full activator activity.

| S-EPMC1137477 | biostudies-other

Production of recombinant streptokinase from Streptococcus pyogenes isolate and its potential for thrombolytic therapy.

Project description:ObjectivesTo produce an effective recombinant streptokinase (rSK) from pathogenic Streptococcus pyogenes isolate in yeast, and evaluate its potential for thrombolytic therapy.MethodsThis study was conducted from November 2012 to December 2013 at King Khalid University, Abha, Kingdom of Saudi Arabia (KSA). Throat swabs collected from 45 pharyngitis patients in Asser Central Hospital, Abha, KSA were used to isolate Streptococcus pyogenes. The bacterial DNA was used for amplification of the streptokinase gene (1200 bp). The gene was cloned and in vitro transcribed in an eukaryotic expression vector that was transformed into yeast Pichia pastoris SMD1168, and the rSK protein was purified and tested for its thrombolytic activity.ResultsThe Streptococcus pyogenes strain was isolated and its DNA nucleotide sequence revealed similarity to other Streptococcus pyogenes in the Gene bank. Sequencing of the amplified gene based on DNA nucleotide sequence revealed a SK gene closely related to other SK genes in the Gene bank. However, based on deduced amino acids sequence, the gene formed a separate cluster different from clusters formed by other examined genes, suggesting a new bacterial isolate and accordingly a new gene. The purified protein showed 82% clot lysis compared to a commercial SK (81%) at an enzyme concentration of 2000 U/ml.ConclusionThe present yeast rSK showed similar thrombolytic activity in vitro as that of a commercial SK, suggesting its potential for thrombolytic therapy and large scale production.

| S-EPMC4362161 | biostudies-literature

Contributions of different modules of the plasminogen-binding Streptococcus pyogenes M-protein that mediate its functional dimerization.

Project description:Group A Streptococcus pyogenes (GAS) is a causative agent of pharyngeal and dermal infections in humans. A major virulence determinant of GAS is its dimeric signature fibrillar M-protein (M-Prt), which is evolutionarily designed in modules, ranging from a hypervariable extracellular N-terminal region to a progressively more highly conserved C-terminus that is covalently anchored to the cell wall. Of the >250 GAS isolates classified, only the subset of skin-trophic Pattern D strains expresses a specific serotype of M-Prt, PAM, that directly binds to host human plasminogen (hPg) via its extracellular NH2-terminal variable A-domain region. This interaction allows these GAS strains to accumulate components of the host fibrinolytic system on their surfaces to serve extracellular functions. While structure-function studies have been accomplished on M-Prts from Pattern A-C GAS isolates with different direct ligand binding properties compared to PAM, much less is known regarding the structure-function relationships of PAM-type M-Prts, particularly their dimerization determinants. To examine these questions, PAMs from seven GAS strains with sequence variations in the NH2-terminal ligand binding domains, as well as truncated versions of PAM, were designed and studied. The results from bioinformatic and biophysical analyses show that the different domains of PAM are disparately engaged in dimerization. From these data, we propose an experimentally-based model for PAM secondary and quaternary structures that is highly dependent on the conserved helical C-terminal C-D-domains. In addition, while the N-terminal regions of PAMs are variable in sequence, the binding properties of hPg and its activated product, plasmin, to the A-domain, remain intact.

| S-EPMC6544907 | biostudies-literature

Structure and Function Characterization of the a1a2 Motifs of Streptococcus pyogenes M Protein in Human Plasminogen Binding.

Project description:Plasminogen (Plg)-binding M protein (PAM) is a group A streptococcal cell surface receptor that is crucial for bacterial virulence. Previous studies revealed that, by binding to the kringle 2 (KR2) domain of host Plg, the pathogen attains a proteolytic microenvironment on the cell surface that facilitates its dissemination from the primary infection site. Each of the PAM molecules in their dimeric assembly consists of two Plg binding motifs (called the a1 and a2 repeats). To date, the molecular interactions between the a1 repeat and KR2 have been structurally characterized, whereas the role of the a2 repeat is less well defined. Here, we report the 1.7-Å x-ray crystal structure of KR2 in complex with a monomeric PAM peptide that contains both the a1 and a2 motifs. The structure reveals how the PAM peptide forms key interactions simultaneously with two KR2 via the high-affinity lysine isosteres within the a1a2 motifs. Further studies, through combined mutagenesis and functional characterization, show that a2 is a stronger KR2 binder than a1, suggesting that these two motifs may play discrete roles in mediating the final PAM-Plg assembly.

| S-EPMC7722781 | biostudies-literature

Expression of recombinant streptokinase from streptococcus pyogenes and its reaction with infected human and murine sera.

Project description:Objective(s)Streptokinase (SKa) is an antigenic protein which is secreted by Streptococcus pyogenes. Streptokinase induces inflammation by complement activation, which may play a role in post infectious diseases. In the present study, recombinant streptokinase from S. pyogenes was produced and showed that recombinant SKa protein was recognized by infected human sera using Western blot analysis.Materials and methodsIn this study, the ska gene from S. pyogenes was amplified and cloned into pET32a which is a prokaryotic expression vector. pET32a-ska was transformed to Escherichia coli BL21 (DE3) pLysS and gene expression was induced by IPTG. Protein production was improved by modification of composition of the bacterial culture media and altering the induction time by IPTG. The expressed protein was purified by affinity chromatography using the Ni-NTA resin. The integrity of the product was confirmed by Westernblot analysis using infected mice. Serum reactivity of five infected individuals was further analyzed against the recombinant SKa protein.ResultsData indicated that recombinant SKa protein from S. pyogenes can be recognized by patient and mice sera. The concentration of the purified recombinant protein was 3.2 mg/L of initial culture. The highest amount of the expressed protein after addition of IPTG was obtained in a bacterial culture without glucose with the culture optical density of 0.8 (OD600 = 0.8). Conclusion : Present data shows, recombinant SKa protein has same epitopes with natural form of this antigen. Recombinant SKa also seemed to be a promising antigen for the serologic diagnosis of S. pyogenes infections.

| S-EPMC3804847 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data