scholarly journals Keeping in Touch with Type-III Secretion System Effectors: Mass Spectrometry-Based Proteomics to Study Effector–Host Protein–Protein Interactions

2020 ◽  
Vol 21 (18) ◽  
pp. 6891
Author(s):  
Margaux De Meyer ◽  
Joren De Ryck ◽  
Sofie Goormachtig ◽  
Petra Van Damme
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Type Iii Secretion ◽  
Large Scale ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Host Protein ◽  
Protein Protein Interactions ◽  
Type Iii ◽  
Recent Advances

Manipulation of host cellular processes by translocated bacterial effectors is key to the success of bacterial pathogens and some symbionts. Therefore, a comprehensive understanding of effectors is of critical importance to understand infection biology. It has become increasingly clear that the identification of host protein targets contributes invaluable knowledge to the characterization of effector function during pathogenesis. Recent advances in mapping protein–protein interaction networks by means of mass spectrometry-based interactomics have enabled the identification of host targets at large-scale. In this review, we highlight mass spectrometry-driven proteomics strategies and recent advances to elucidate type-III secretion system effector–host protein–protein interactions. Furthermore, we highlight approaches for defining spatial and temporal effector–host interactions, and discuss possible avenues for studying natively delivered effectors in the context of infection. Overall, the knowledge gained when unravelling effector complexation with host factors will provide novel opportunities to control infectious disease outcomes.

scholarly journals New Protein-Protein Interactions Identified for the Regulatory and Structural Components and Substrates of the Type III Secretion System of the Phytopathogen Xanthomonas axonopodis Pathovar citri

2004 ◽  
Vol 186 (18) ◽  
pp. 6186-6197 ◽  
Author(s):  
Marcos C. Alegria ◽  
Cassia Docena ◽  
Leticia Khater ◽  
Carlos H. I. Ramos ◽  
Ana C. R. da Silva ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Type Iii Secretion ◽  
Molecular Mechanisms ◽  
Functional Integration ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
System Response ◽  
Protein Protein Interactions ◽  
Xanthomonas Axonopodis ◽  
Type Iii

ABSTRACT We have initiated a project to identify protein-protein interactions involved in the pathogenicity of the bacterial plant pathogen Xanthomonas axonopodis pv. citri. Using a yeast two-hybrid system based on Gal4 DNA-binding and activation domains, we have focused on identifying interactions involving subunits, regulators, and substrates of the type III secretion system coded by the hrp (for hypersensitive response and pathogenicity), hrc (for hrp conserved), and hpa (for hrp associated) genes. We have identified several previously uncharacterized interactions involving (i) HrpG, a two-component system response regulator responsible for the expression of X. axonopodis pv. citri hrp operons, and XAC0095, a previously uncharacterized protein encountered only in Xanthomonas spp.; (ii) HpaA, a protein secreted by the type III secretion system, HpaB, and the C-terminal domain of HrcV; (iii) HrpB1, HrpD6, and HrpW; and (iv) HrpB2 and HrcU. Homotropic interactions were also identified for the ATPase HrcN. These newly identified protein-protein interactions increase our understanding of the functional integration of phytopathogen-specific type III secretion system components and suggest new hypotheses regarding the molecular mechanisms underlying Xanthomonas pathogenicity.

scholarly journals Protein-Protein Interactions within Type III Secretion System-Dependent Pili of Rhizobium sp. Strain NGR234

2007 ◽  
Vol 190 (2) ◽  
pp. 750-754 ◽  
Author(s):  
Maged M. Saad ◽  
Christian Staehelin ◽  
William J. Broughton ◽  
William J. Deakin
Keyword(s):  
Protein Secretion ◽  
Protein Interactions ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Partial Purification ◽  
Protein Protein Interactions ◽  
Type Iii ◽  
Biochemical Assays ◽  
Rhizobium Sp

ABSTRACT Pili synthesized by the type III secretion system of Rhizobium species strain NGR234 are essential for protein secretion and thus for efficient symbiosis with many legumes. Isolation and partial purification of these pili showed that they are composed of at least three proteins, NopA, NopB, and NopX. Using biochemical assays, we show here that these proteins interact directly with one another.

scholarly journals Functional Characterization of SsaE, a Novel Chaperone Protein of the Type III Secretion System Encoded by Salmonella Pathogenicity Island 2

2009 ◽  
Vol 191 (22) ◽  
pp. 6843-6854 ◽  
Author(s):  
Tsuyoshi Miki ◽  
Yoshio Shibagaki ◽  
Hirofumi Danbara ◽  
Nobuhiko Okada
Keyword(s):  
Protein Interactions ◽  
Type Iii Secretion ◽  
Functional Characterization ◽  
Coiled Coil ◽  
Type Iii Secretion System ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Type Iii ◽  
Serovar Typhimurium

ABSTRACT The type III secretion system (T3SS) encoded by Salmonella pathogenicity island 2 (SPI-2) is involved in systemic infection and intracellular replication of Salmonella enterica serovar Typhimurium. In this study, we investigated the function of SsaE, a small cytoplasmic protein encoded within the SPI-2 locus, which shows structural similarity to the T3SS class V chaperones. An S. enterica serovar Typhimurium ssaE mutant failed to secrete SPI-2 translocator SseB and SPI-2-dependent effector PipB proteins. Coimmunoprecipitation and mass spectrometry analyses using an SsaE-FLAG fusion protein indicated that SsaE interacts with SseB and a putative T3SS-associated ATPase, SsaN. A series of deleted and point-mutated SsaE-FLAG fusion proteins revealed that the C-terminal coiled-coil domain of SsaE is critical for protein-protein interactions. Although SseA was reported to be a chaperone for SseB and to be required for its secretion and stability in the bacterial cytoplasm, an sseA deletion mutant was able to secrete the SseB in vitro when plasmid-derived SseB was overexpressed. In contrast, ssaE mutant strains could not transport SseB extracellularly under the same assay conditions. In addition, an ssaE(I55G) point-mutated strain that expresses the SsaE derivative lacking the ability to form a C-terminal coiled-coil structure showed attenuated virulence comparable to that of an SPI-2 T3SS null mutant, suggesting that the coiled-coil interaction of SsaE is absolutely essential for the functional SPI-2 T3SS and for Salmonella virulence. Based on these findings, we propose that SsaE recognizes translocator SseB and controls its secretion via SPI-2 type III secretion machinery.

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