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Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system
BACKGROUND: Type III secretion systems (T3SS) are essential virulence factors of most Gram-negative bacterial pathogens. T3SS deliver effector proteins directly into the cytoplasm of eukaryotic target cells and for this function, the insertion of a subset of T3SS proteins into the target cell membra...
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2010
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2873485/ https://www.ncbi.nlm.nih.gov/pubmed/20377892 http://dx.doi.org/10.1186/1471-2180-10-104 |
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author | Hölzer, Stefanie U Hensel, Michael |
author_facet | Hölzer, Stefanie U Hensel, Michael |
author_sort | Hölzer, Stefanie U |
collection | PubMed |
description | BACKGROUND: Type III secretion systems (T3SS) are essential virulence factors of most Gram-negative bacterial pathogens. T3SS deliver effector proteins directly into the cytoplasm of eukaryotic target cells and for this function, the insertion of a subset of T3SS proteins into the target cell membrane is important. These proteins form hetero-oligomeric pores acting as translocon for the delivery of effector proteins. Salmonella enterica is a facultative intracellular pathogen that uses the Salmonella Pathogenicity Island 2 (SPI2)-encoded T3SS to manipulate host cells in order to survive and proliferate within the Salmonella-containing vacuole of host cells. Previous work showed that SPI2-encoded SseB, SseC and SseD act to form the translocon of the SPI2-T3SS. RESULTS: Here we investigated the structural requirements of SseB and SseD to form a functional translocon. Based on bioinformatic predictions, deletional analyses of SseB and SseD were performed and the effect on secretion by the T3SS, formation of a translocon, translocation of effector proteins and intracellular replication was investigated. Our data showed that both SseB and SseD are very sensitive towards alterations of the primary structure of the proteins. Although proteins encoded by mutant alleles were still secreted, we observed that all mutations resulted in a loss of function of the SPI2-T3SS. CONCLUSION: These observations indicate that translocon proteins of the SPI2-T3SS are highly evolved towards the formation of multi-subunit complex in the host cell membrane. Structural alterations are not tolerated and abrogate translocon function. |
format | Text |
id | pubmed-2873485 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-28734852010-05-20 Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system Hölzer, Stefanie U Hensel, Michael BMC Microbiol Research article BACKGROUND: Type III secretion systems (T3SS) are essential virulence factors of most Gram-negative bacterial pathogens. T3SS deliver effector proteins directly into the cytoplasm of eukaryotic target cells and for this function, the insertion of a subset of T3SS proteins into the target cell membrane is important. These proteins form hetero-oligomeric pores acting as translocon for the delivery of effector proteins. Salmonella enterica is a facultative intracellular pathogen that uses the Salmonella Pathogenicity Island 2 (SPI2)-encoded T3SS to manipulate host cells in order to survive and proliferate within the Salmonella-containing vacuole of host cells. Previous work showed that SPI2-encoded SseB, SseC and SseD act to form the translocon of the SPI2-T3SS. RESULTS: Here we investigated the structural requirements of SseB and SseD to form a functional translocon. Based on bioinformatic predictions, deletional analyses of SseB and SseD were performed and the effect on secretion by the T3SS, formation of a translocon, translocation of effector proteins and intracellular replication was investigated. Our data showed that both SseB and SseD are very sensitive towards alterations of the primary structure of the proteins. Although proteins encoded by mutant alleles were still secreted, we observed that all mutations resulted in a loss of function of the SPI2-T3SS. CONCLUSION: These observations indicate that translocon proteins of the SPI2-T3SS are highly evolved towards the formation of multi-subunit complex in the host cell membrane. Structural alterations are not tolerated and abrogate translocon function. BioMed Central 2010-04-08 /pmc/articles/PMC2873485/ /pubmed/20377892 http://dx.doi.org/10.1186/1471-2180-10-104 Text en Copyright ©2010 Hölzer and Hensel; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research article Hölzer, Stefanie U Hensel, Michael Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title | Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title_full | Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title_fullStr | Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title_full_unstemmed | Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title_short | Functional dissection of translocon proteins of the Salmonella Pathogenicity Island 2-encoded type III secretion system |
title_sort | functional dissection of translocon proteins of the salmonella pathogenicity island 2-encoded type iii secretion system |
topic | Research article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2873485/ https://www.ncbi.nlm.nih.gov/pubmed/20377892 http://dx.doi.org/10.1186/1471-2180-10-104 |
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