The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling.
Chlamydia trachomatis, the causative agent of trachoma and sexually transmitted infections, employs a type III secretion (T3S) system to deliver effector proteins into host epithelial cells to establish a replicative vacuole. Aside from the phosphoprotein TARP, a Chlamydia effector that promotes act...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2014-02-01
|
| Series: | PLoS Pathogens |
| Online Access: | https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1003954&type=printable |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850022897624547328 |
|---|---|
| author | Yi-Shan Chen Robert J Bastidas Hector A Saka Victoria K Carpenter Kristian L Richards Gregory V Plano Raphael H Valdivia |
| author_facet | Yi-Shan Chen Robert J Bastidas Hector A Saka Victoria K Carpenter Kristian L Richards Gregory V Plano Raphael H Valdivia |
| author_sort | Yi-Shan Chen |
| collection | DOAJ |
| description | Chlamydia trachomatis, the causative agent of trachoma and sexually transmitted infections, employs a type III secretion (T3S) system to deliver effector proteins into host epithelial cells to establish a replicative vacuole. Aside from the phosphoprotein TARP, a Chlamydia effector that promotes actin re-arrangements, very few factors mediating bacterial entry and early inclusion establishment have been characterized. Like many T3S effectors, TARP requires a chaperone (Slc1) for efficient translocation into host cells. In this study, we defined proteins that associate with Slc1 in invasive C. trachomatis elementary bodies (EB) by immunoprecipitation coupled with mass spectrometry. We identified Ct875, a new Slc1 client protein and T3S effector, which we renamed TepP (Translocated early phosphoprotein). We provide evidence that T3S effectors form large molecular weight complexes with Scl1 in vitro and that Slc1 enhances their T3S-dependent secretion in a heterologous Yersinia T3S system. We demonstrate that TepP is translocated early during bacterial entry into epithelial cells and is phosphorylated at tyrosine residues by host kinases. However, TepP phosphorylation occurs later than TARP, which together with the finding that Slc1 preferentially engages TARP in EBs leads us to postulate that these effectors are translocated into the host cell at different stages during C. trachomatis invasion. TepP co-immunoprecipitated with the scaffolding proteins CrkI-II during infection and Crk was recruited to EBs at entry sites where it remained associated with nascent inclusions. Importantly, C. trachomatis mutants lacking TepP failed to recruit CrkI-II to inclusions, providing genetic confirmation of a direct role for this effector in the recruitment of a host factor. Finally, endocervical epithelial cells infected with a tepP mutant showed altered expression of a subset of genes associated with innate immune responses. We propose a model wherein TepP acts downstream of TARP to recruit scaffolding proteins at entry sites to initiate and amplify signaling cascades important for the regulation of innate immune responses to Chlamydia. |
| format | Article |
| id | doaj-art-b2a098f21faf420c86ab2cf2ce755593 |
| institution | DOAJ |
| issn | 1553-7366 1553-7374 |
| language | English |
| publishDate | 2014-02-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj-art-b2a098f21faf420c86ab2cf2ce7555932025-08-20T03:01:31ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742014-02-01102e100395410.1371/journal.ppat.1003954The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling.Yi-Shan ChenRobert J BastidasHector A SakaVictoria K CarpenterKristian L RichardsGregory V PlanoRaphael H ValdiviaChlamydia trachomatis, the causative agent of trachoma and sexually transmitted infections, employs a type III secretion (T3S) system to deliver effector proteins into host epithelial cells to establish a replicative vacuole. Aside from the phosphoprotein TARP, a Chlamydia effector that promotes actin re-arrangements, very few factors mediating bacterial entry and early inclusion establishment have been characterized. Like many T3S effectors, TARP requires a chaperone (Slc1) for efficient translocation into host cells. In this study, we defined proteins that associate with Slc1 in invasive C. trachomatis elementary bodies (EB) by immunoprecipitation coupled with mass spectrometry. We identified Ct875, a new Slc1 client protein and T3S effector, which we renamed TepP (Translocated early phosphoprotein). We provide evidence that T3S effectors form large molecular weight complexes with Scl1 in vitro and that Slc1 enhances their T3S-dependent secretion in a heterologous Yersinia T3S system. We demonstrate that TepP is translocated early during bacterial entry into epithelial cells and is phosphorylated at tyrosine residues by host kinases. However, TepP phosphorylation occurs later than TARP, which together with the finding that Slc1 preferentially engages TARP in EBs leads us to postulate that these effectors are translocated into the host cell at different stages during C. trachomatis invasion. TepP co-immunoprecipitated with the scaffolding proteins CrkI-II during infection and Crk was recruited to EBs at entry sites where it remained associated with nascent inclusions. Importantly, C. trachomatis mutants lacking TepP failed to recruit CrkI-II to inclusions, providing genetic confirmation of a direct role for this effector in the recruitment of a host factor. Finally, endocervical epithelial cells infected with a tepP mutant showed altered expression of a subset of genes associated with innate immune responses. We propose a model wherein TepP acts downstream of TARP to recruit scaffolding proteins at entry sites to initiate and amplify signaling cascades important for the regulation of innate immune responses to Chlamydia.https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1003954&type=printable |
| spellingShingle | Yi-Shan Chen Robert J Bastidas Hector A Saka Victoria K Carpenter Kristian L Richards Gregory V Plano Raphael H Valdivia The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. PLoS Pathogens |
| title | The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. |
| title_full | The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. |
| title_fullStr | The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. |
| title_full_unstemmed | The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. |
| title_short | The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling. |
| title_sort | chlamydia trachomatis type iii secretion chaperone slc1 engages multiple early effectors including tepp a tyrosine phosphorylated protein required for the recruitment of crki ii to nascent inclusions and innate immune signaling |
| url | https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1003954&type=printable |
| work_keys_str_mv | AT yishanchen thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT robertjbastidas thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT hectorasaka thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT victoriakcarpenter thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT kristianlrichards thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT gregoryvplano thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT raphaelhvaldivia thechlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT yishanchen chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT robertjbastidas chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT hectorasaka chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT victoriakcarpenter chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT kristianlrichards chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT gregoryvplano chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling AT raphaelhvaldivia chlamydiatrachomatistypeiiisecretionchaperoneslc1engagesmultipleearlyeffectorsincludingteppatyrosinephosphorylatedproteinrequiredfortherecruitmentofcrkiiitonascentinclusionsandinnateimmunesignaling |