scholarly journals Invasion of Epithelial Cells Is Correlated with Secretion of Biosurfactant via the Type 3 Secretion System (T3SS) of Shigella flexneri

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Duchel Jeanedvi Kinouani Kinavouidi ◽  
Christian Aimé Kayath ◽  
Etienne Nguimbi
Keyword(s):  
Organic Solvent ◽  
Type Iii Secretion ◽  
Shigella Flexneri ◽  
Secretion System ◽  
Extracellular Medium ◽  
Membrane Interfaces ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Hydrophobic Areas

Biosurfactants are amphipathic molecules produced by many microorganisms, usually bacteria, fungi, and yeasts. They possess the property of reducing the tension of the membrane interfaces. No studies have been conducted on Shigella species showing the role of biosurfactant-like molecules (BLM) in pathogenicity. The aim of this study is to assess the ability of Shigella environmental and clinical strains to produce BLM and investigate the involvement of biosurfactants in pathogenicity. Our study has shown that BLM are secreted in the extracellular medium with EI24 ranging from 80% to 100%. The secretion is depending on the type III secretion system (T3SS). Moreover, our results have shown that S. flexneri, S. boydii, and S. sonnei are able to interact with hydrophobic areas with 17.64%, 21.42%, and 22.22% hydrophobicity, respectively. BLM secretion is totally prevented due to inhibition of T3SS by 100 mM benzoic and 1.5 mg/ml salicylic acids. P. aeruginosa harboring T3SS is able to produce 100% of BLM in the presence or in the absence of both T3SS inhibitors. The secreted BLM are extractable with an organic solvent such as chloroform, and this could entirely be considered a lipopeptide or polypeptide compound. Secretion of BLM allows some Shigella strains to induce multicellular phenomena like “swarming.”

scholarly journals Invasion of epithelial cells are correlated with secretion of Biosurfactant via the type 3 secretion system (SST3) of Shigella flexneri

2020 ◽  
Author(s):  
Duchel Jeanedvi Kinouani Kinavouidi ◽  
Christian Aimé Kayath ◽  
Etienne NGuimbi
Keyword(s):  
Epithelial Cells ◽  
Type Iii Secretion ◽  
Shigella Flexneri ◽  
Secretion System ◽  
Extracellular Medium ◽  
Diesel Fuels ◽  
Membrane Interfaces ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Hydrophobic Areas

AbstractBiosurfactants are amphipathic molecules produced by many microorganisms, usually bacteria, fungi and yeasts. They possess the property of reducing the tension of the membrane interfaces. No studies have been conducted on Shigella species showing their involvement of biosurfactant like molecules (BLM) in pathogenicity. This study aims to show that environmental and clinical strains of Shigella are able to produce BLM by emulsifying gasoline and diesel fuels. Our study has shown that BLM are secreted in the extracellular medium with EI24 ranging from 80 to 100%. The secretion is depending on the type III secretion system (T3SS). We did show that S. flexneri, S. boydii and S. sonnei are able to interact with hydrophobic areas with respectively 17.64%, 21.42% and 22.22% of hydrophobicity. 100 mM Benzoic and 1.5mg/mL Salycilic acids have been inhibited T3SS and this totally stops the BLM secretion. Pseudomonas aeruginosa which has T3SS is able to produce 100% of BLM in the presence or in the absence of both T3SS inhibitors. The secreted BLM is extractable with an organic solvent such as chloroform and could entirely be considered like lipopeptide or polypeptidic compound. By secreting BLM, Shigella is able to perform multicellular phenomena like “swarming” allowing to invade and disseminate inside epithelial cells.

scholarly journals Role of the acquisition of a type 3 secretion system in the emergence of novel pathogenic strains of Xanthomonas

2018 ◽  
Vol 20 (1) ◽  
pp. 33-50 ◽  
Author(s):  
Valérian Meline ◽  
Wesley Delage ◽  
Chrystelle Brin ◽  
Camille Li-Marchetti ◽  
Daniel Sochard ◽  
...  
Keyword(s):  
Secretion System ◽  
Type 3 Secretion System ◽  
Type 3

scholarly journals Structures of the Shigella flexneri Type 3 Secretion System Protein MxiC Reveal Conformational Variability Amongst Homologues

2008 ◽  
Vol 377 (4) ◽  
pp. 985-992 ◽  
Author(s):  
Janet E. Deane ◽  
Pietro Roversi ◽  
Carole King ◽  
Steven Johnson ◽  
Susan M. Lea
Keyword(s):  
Shigella Flexneri ◽  
Secretion System ◽  
Conformational Variability ◽  
Type 3 Secretion System ◽  
Type 3

scholarly journals Regulation by ToxR-Like Proteins Converges onvttRBExpression To Control Type 3 Secretion System-Dependent Caco2-BBE Cytotoxicity in Vibrio cholerae

2016 ◽  
Vol 198 (11) ◽  
pp. 1675-1682 ◽  
Author(s):  
Kelly A. Miller ◽  
Madeline K. Sofia ◽  
Jacob W. A. Weaver ◽  
Christopher H. Seward ◽  
Michelle Dziejman
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Vibrio Cholerae ◽  
Secretion System ◽  
Content Type ◽  
Transcriptional Regulatory ◽  
Type 3 Secretion System ◽  
Type 3

ABSTRACTGenes carried on the type 3 secretion system (T3SS) pathogenicity island ofVibrio choleraenon-O1/non-O139 serogroup strain AM-19226 must be precisely regulated in order for bacteria to cause disease. Previously reported results showed that both T3SS function and the presence of bile are required to cause Caco2-BBE cell cytotoxicity during coculture with strain AM-19226. We therefore investigated additional parameters affectingin vitrocell death, including bacterial load and the role of three transmembrane transcriptional regulatory proteins, VttRA, VttRB, and ToxR. VttRAand VttRBare encoded on the horizontally acquired T3SS genomic island, whereas ToxR is encoded on the ancestral chromosome. While strains carrying deletions in any one of the three transcriptional regulatory genes are unable to cause eukaryotic cell death, the results of complementation studies point to a hierarchy of regulatory control that converges onvttRBexpression. The data suggest both that ToxR and VttRAact upstream of VttRBand that modifying the level of eithervttRAorvttRBexpression can strongly influence T3SS gene expression. We therefore propose a model whereby T3SS activity and, hence,in vitrocytotoxicity are ultimately regulated byvttRBexpression.IMPORTANCEIn contrast to O1 and O139 serogroupV. choleraestrains that cause cholera using two main virulence factors (toxin-coregulated pilus [TCP] and cholera toxin [CT]), O39 serogroup strain AM-19226 uses a type 3 secretion system as its principal virulence mechanism. Although the regulatory network governing TCP and CT expression is well understood, the factors influencing T3SS-associated virulence are not. Using anin vitromammalian cell model to investigate the role of three ToxR-like transmembrane transcriptional activators in causing T3SS-dependent cytotoxicity, we found that expression levels and a hierarchical organization were important for promoting T3SS gene expression. Furthermore, our results suggest that horizontally acquired, ToxR-like proteins act in concert with the ancestral ToxR protein to orchestrate T3SS-mediated pathogenicity.

scholarly journals The type 3 secretion system requires actin polymerization to open translocon pores

2021 ◽  
Vol 17 (9) ◽  
pp. e1009932
Author(s):  
Brian C. Russo ◽  
Jeffrey K. Duncan-Lowey ◽  
Poyin Chen ◽  
Marcia B. Goldberg
Keyword(s):  
Plasma Membrane ◽  
Actin Polymerization ◽  
Shigella Flexneri ◽  
Coiled Coil ◽  
Model Organism ◽  
Secretion System ◽  
Pore Channel ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Pore Protein

Many bacterial pathogens require a type 3 secretion system (T3SS) to establish a niche. Host contact activates bacterial T3SS assembly of a translocon pore in the host plasma membrane. Following pore formation, the T3SS docks onto the translocon pore. Docking establishes a continuous passage that enables the translocation of virulence proteins, effectors, into the host cytosol. Here we investigate the contribution of actin polymerization to T3SS-mediated translocation. Using the T3SS model organism Shigella flexneri, we show that actin polymerization is required for assembling the translocon pore in an open conformation, thereby enabling effector translocation. Opening of the pore channel is associated with a conformational change to the pore, which is dependent upon actin polymerization and a coiled-coil domain in the pore protein IpaC. Analysis of an IpaC mutant that is defective in ruffle formation shows that actin polymerization-dependent pore opening is distinct from the previously described actin polymerization-dependent ruffles that are required for bacterial internalization. Moreover, actin polymerization is not required for other pore functions, including docking or pore protein insertion into the plasma membrane. Thus, activation of the T3SS is a multilayered process in which host signals are sensed by the translocon pore leading to the activation of effector translocation.

scholarly journals The type 3 secretion system requires actin polymerization to open translocon pores

2021 ◽  
Author(s):  
Brian C. Russo ◽  
Jeffrey K. Duncan-Lowey ◽  
Poyin Chen ◽  
Marcia B. Goldberg
Keyword(s):  
Plasma Membrane ◽  
Actin Polymerization ◽  
Shigella Flexneri ◽  
Coiled Coil ◽  
Model Organism ◽  
Secretion System ◽  
Pore Channel ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Pore Protein

Many bacterial pathogens require a type 3 secretion system (T3SS) to establish a niche. Host contact activates bacterial T3SS assembly of a translocon pore in the host plasma membrane. Following pore formation, the T3SS docks onto the translocon pore. Docking establishes a continuous passage that enables the translocation of virulence proteins, effectors, into the host cytosol. Here we investigate the contribution of actin polymerization to T3SS-mediated translocation. Using the T3SS model organism Shigella flexneri, we show that actin polymerization is required for assembling the translocon pore in an open conformation, thereby enabling effector translocation. Opening of the pore channel is associated with a conformational change to the pore, which is dependent upon actin polymerization and a coiled-coil domain in the pore protein IpaC. An IpaC mutant is identified that shows actin polymerization-dependent pore opening is distinct from the previously described actin polymerization-dependent ruffles that are required for bacterial internalization. Moreover, actin polymerization is not required for other pore functions, including docking or pore protein insertion into the plasma membrane. Thus, activation of the T3SS is a multilayered process in which host signals are sensed by the translocon pore leading to the activation of effector translocation.

Spa13 of Shigella flexneri has a dual role: chaperone escort and export gate-activator switch of the type III secretion system

Microbiology ◽  
2014 ◽  
Vol 160 (1) ◽  
pp. 130-141 ◽  
Author(s):  
Youness Cherradi ◽  
Abderrahman Hachani ◽  
Abdelmounaaïm Allaoui
Keyword(s):  
Type Iii Secretion ◽  
Shigella Flexneri ◽  
Secretion System ◽  
Dual Role ◽  
Inner Membrane ◽  
Type Iii ◽  
Inner Membrane Protein ◽  
Soluble Components ◽  
Made In

The type III secretion apparatus (T3SA) is used by numerous Gram-negative pathogens to inject virulence factors into eukaryotic cells. The Shigella flexneri T3SA spans the bacterial envelope and its assembly requires the products of ~20 mxi and spa genes. Despite progress made in understanding how the T3SA is assembled, the role of several predicted soluble components, such as Spa13, remains elusive. Here, we show that the secretion defect of the spa13 mutant is associated with lack of T3SA assembly which is partly due to the instability of the needle component MxiH. In contrast to its Yersinia counterpart, Spa13 is not a secreted protein. We identified a network of interactions between Spa13 and the ATPase Spa47, the C-ring protein Spa33, and the inner-membrane protein Spa40. Moreover, we revealed a Spa13 interaction with the inner-membrane MxiA and showed that overexpression of the large cytoplasmic domain of MxiA in the WT background shuts off secretion. Lastly, we demonstrated that Spa13 interacts with the cleaved form of Spa40 and with the translocator chaperone IpgC, suggesting that Spa13 intervenes during the secretion hierarchy switch process. Collectively, our results support a dual role of Spa13 as a chaperone escort and as an export gate-activator switch.

scholarly journals Activation of the type 3 secretion system of enteropathogenic E. coli leads to reprogramming of its lipid metabolism

2020 ◽  
Author(s):  
Anish Zacharia ◽  
Ritesh Ranjan Pal ◽  
Naama Katsowich ◽  
Chanchal Thomas Mannully ◽  
Sivan Alfandary ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Type Iii Secretion ◽  
Rna Binding ◽  
Secretion System ◽  
Host Cells ◽  
E Coli ◽  
A Cell ◽  
Bacterial Fitness ◽  
Type 3 Secretion System ◽  
Type 3

AbstractThe type III secretion system (T3SS) is critical for the virulence of enteropathogenic E. coli (EPEC), an important human pathogen. T3SS is activated upon host attachment leading to effector injection, which is associated with repression of CsrA, an RNA binding protein, and a global posttranscriptional regulator. CsrA repression results in gene expression reprogramming, which contributes to EPEC adaptation to a cell-adherent lifestyle. However, how this reprogramming influences EPEC physiology remains poorly understood. By combining genetic analyses, metabolomics and lipidomics, and data mining from reported datasets, we show that activation of the EPEC T3SS is associated with massive metabolic shifts, in particular, remodeling of lipid metabolism. The latter includes a shift from phospholipids towards lysophospholipids and cardiolipins and from ubiquinones and menaquinones production to the synthesis of undecaprenyl isoprenoids, concomitant to upregulation of O-antigen biosynthesis. We predict that the lipid composition remodeling upon attachment to host cells and T3SS activation contributes to bacterial fitness and promote host colonization.

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