The type III secretion system and its role in the multicellular behaviour of Yersinia species
Pathogenic Yersinia translocate Yersinia outer protein (YOP) effectors directly into eukaryotic cells via a virulence plasmid (pYV/pCD1)-encoded type III secretion system (T3SS) injectisome, where they interfere with host signalling pathways and inhibit inflammatory responses. A temperature of 37°C...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
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2018
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| Online Access: | https://eprints.nottingham.ac.uk/55324/ |
| _version_ | 1848799147297079296 |
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| author | Barratt, Natalie Alice |
| author_facet | Barratt, Natalie Alice |
| author_sort | Barratt, Natalie Alice |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Pathogenic Yersinia translocate Yersinia outer protein (YOP) effectors directly into eukaryotic cells via a virulence plasmid (pYV/pCD1)-encoded type III secretion system (T3SS) injectisome, where they interfere with host signalling pathways and inhibit inflammatory responses. A temperature of 37°C is required for injectisome assembly and YOP export is triggered by host cell contact or chelation of calcium ions. Yersinia pseudotuberculosis and Yersinia pestis both utilise N-acylhomoserine lactone (AHL) -dependent quorum sensing (QS), a process of signal molecule mediated cell-to-cell communication for coordinating gene expression within a bacterial population. In Y. pseudotuberculosis, T3S, motility, auto-aggregation (AAg) and biofilm formation on Caenorhabditis elegans are all under QS control.
At 37°C, Y. pseudotuberculosis exhibits a T3SS-dependent AAg phenotype that is subject to AHL-mediated negative regulation. The rate of AAg and the size of the auto-aggregates was also found to be dependent on QS. The aims of this thesis were to determine the specific proteins responsible for this phenotype by screening T3SS mutants and assessing their ability to auto-aggregate. The adhesin YadA is a known AAg factor, however T3SS-dependent AAg was found to be YadA-independent.
Previously mutation of both Y. pseudotuberculosis AHL synthase genes, ytbI and ypsI, was shown to attenuate biofilm formation on the living (biotic) surface of C. elegans in a pYV-dependent manner. Since this finding suggested a role for the T3SS in biofilm formation, mutations in yopB, yopH, yscF, yscJ and lcrV were introduced into the AHL-negative synthase mutant and they were screened for their ability to form biofilm. |
| first_indexed | 2025-11-14T20:31:02Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-55324 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:31:02Z |
| publishDate | 2018 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-553242025-02-28T14:15:54Z https://eprints.nottingham.ac.uk/55324/ The type III secretion system and its role in the multicellular behaviour of Yersinia species Barratt, Natalie Alice Pathogenic Yersinia translocate Yersinia outer protein (YOP) effectors directly into eukaryotic cells via a virulence plasmid (pYV/pCD1)-encoded type III secretion system (T3SS) injectisome, where they interfere with host signalling pathways and inhibit inflammatory responses. A temperature of 37°C is required for injectisome assembly and YOP export is triggered by host cell contact or chelation of calcium ions. Yersinia pseudotuberculosis and Yersinia pestis both utilise N-acylhomoserine lactone (AHL) -dependent quorum sensing (QS), a process of signal molecule mediated cell-to-cell communication for coordinating gene expression within a bacterial population. In Y. pseudotuberculosis, T3S, motility, auto-aggregation (AAg) and biofilm formation on Caenorhabditis elegans are all under QS control. At 37°C, Y. pseudotuberculosis exhibits a T3SS-dependent AAg phenotype that is subject to AHL-mediated negative regulation. The rate of AAg and the size of the auto-aggregates was also found to be dependent on QS. The aims of this thesis were to determine the specific proteins responsible for this phenotype by screening T3SS mutants and assessing their ability to auto-aggregate. The adhesin YadA is a known AAg factor, however T3SS-dependent AAg was found to be YadA-independent. Previously mutation of both Y. pseudotuberculosis AHL synthase genes, ytbI and ypsI, was shown to attenuate biofilm formation on the living (biotic) surface of C. elegans in a pYV-dependent manner. Since this finding suggested a role for the T3SS in biofilm formation, mutations in yopB, yopH, yscF, yscJ and lcrV were introduced into the AHL-negative synthase mutant and they were screened for their ability to form biofilm. 2018-12-13 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/55324/1/Natalie%20Alice%20Barratt%20Thesis%202018%20PVE.pdf Barratt, Natalie Alice (2018) The type III secretion system and its role in the multicellular behaviour of Yersinia species. PhD thesis, University of Nottingham. Yersinia Quorum sensing Type III secretion Biofilm |
| spellingShingle | Yersinia Quorum sensing Type III secretion Biofilm Barratt, Natalie Alice The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title | The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title_full | The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title_fullStr | The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title_full_unstemmed | The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title_short | The type III secretion system and its role in the multicellular behaviour of Yersinia species |
| title_sort | type iii secretion system and its role in the multicellular behaviour of yersinia species |
| topic | Yersinia Quorum sensing Type III secretion Biofilm |
| url | https://eprints.nottingham.ac.uk/55324/ |