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Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus

Legionella pneumophila is the causative agent of a pneumonia termed Legionnaires’ disease. The facultative intracellular bacterium employs the Icm/Dot type IV secretion system (T4SS) and a plethora of translocated “effector” proteins to interfere with host vesicle trafficking pathways and establish...

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Detalles Bibliográficos
Autores principales: Weber, Stephen, Steiner, Bernhard, Welin, Amanda, Hilbi, Hubert
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299486/
https://www.ncbi.nlm.nih.gov/pubmed/30538188
http://dx.doi.org/10.1128/mBio.02420-18
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author Weber, Stephen
Steiner, Bernhard
Welin, Amanda
Hilbi, Hubert
author_facet Weber, Stephen
Steiner, Bernhard
Welin, Amanda
Hilbi, Hubert
author_sort Weber, Stephen
collection PubMed
description Legionella pneumophila is the causative agent of a pneumonia termed Legionnaires’ disease. The facultative intracellular bacterium employs the Icm/Dot type IV secretion system (T4SS) and a plethora of translocated “effector” proteins to interfere with host vesicle trafficking pathways and establish a replicative niche, the Legionella-containing vacuole (LCV). Internalization of the pathogen and the events immediately ensuing are accompanied by host cell-mediated phosphoinositide (PI) lipid changes and the Icm/Dot-controlled conversion of the LCV from a PtdIns(3)P-positive vacuole into a PtdIns(4)P-positive replication-permissive compartment, which tightly associates with the endoplasmic reticulum. The source and formation of PtdIns(4)P are ill-defined. Using dually labeled Dictyostelium discoideum amoebae and real-time high-resolution confocal laser scanning microscopy (CLSM), we show here that nascent LCVs continuously capture and accumulate PtdIns(4)P-positive vesicles from the host cell. Trafficking of these PtdIns(4)P-positive vesicles to LCVs occurs independently of the Icm/Dot system, but their sustained association requires a functional T4SS. During the infection, PtdIns(3)P-positive membranes become compacted and segregated from the LCV, and PtdIns(3)P-positive vesicles traffic to the LCV but do not fuse. Moreover, using eukaryotic and prokaryotic PtdIns(4)P probes (2×PH(FAPP)-green fluorescent protein [2×PH(FAPP)-GFP] and P4C(SidC)-GFP, respectively) along with Arf1-GFP, we show that PtdIns(4)P-rich membranes of the trans-Golgi network associate with the LCV. Intriguingly, the interaction dynamics of 2×PH(FAPP)-GFP and P4C(SidC)-GFP are spatially separable and reveal the specific PtdIns(4)P pool from which the LCV PI originates. These findings provide high-resolution real-time insights into how L. pneumophila exploits the cellular dynamics of membrane-bound PtdIns(4)P for LCV formation.
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spelling pubmed-62994862018-12-28 Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus Weber, Stephen Steiner, Bernhard Welin, Amanda Hilbi, Hubert mBio Research Article Legionella pneumophila is the causative agent of a pneumonia termed Legionnaires’ disease. The facultative intracellular bacterium employs the Icm/Dot type IV secretion system (T4SS) and a plethora of translocated “effector” proteins to interfere with host vesicle trafficking pathways and establish a replicative niche, the Legionella-containing vacuole (LCV). Internalization of the pathogen and the events immediately ensuing are accompanied by host cell-mediated phosphoinositide (PI) lipid changes and the Icm/Dot-controlled conversion of the LCV from a PtdIns(3)P-positive vacuole into a PtdIns(4)P-positive replication-permissive compartment, which tightly associates with the endoplasmic reticulum. The source and formation of PtdIns(4)P are ill-defined. Using dually labeled Dictyostelium discoideum amoebae and real-time high-resolution confocal laser scanning microscopy (CLSM), we show here that nascent LCVs continuously capture and accumulate PtdIns(4)P-positive vesicles from the host cell. Trafficking of these PtdIns(4)P-positive vesicles to LCVs occurs independently of the Icm/Dot system, but their sustained association requires a functional T4SS. During the infection, PtdIns(3)P-positive membranes become compacted and segregated from the LCV, and PtdIns(3)P-positive vesicles traffic to the LCV but do not fuse. Moreover, using eukaryotic and prokaryotic PtdIns(4)P probes (2×PH(FAPP)-green fluorescent protein [2×PH(FAPP)-GFP] and P4C(SidC)-GFP, respectively) along with Arf1-GFP, we show that PtdIns(4)P-rich membranes of the trans-Golgi network associate with the LCV. Intriguingly, the interaction dynamics of 2×PH(FAPP)-GFP and P4C(SidC)-GFP are spatially separable and reveal the specific PtdIns(4)P pool from which the LCV PI originates. These findings provide high-resolution real-time insights into how L. pneumophila exploits the cellular dynamics of membrane-bound PtdIns(4)P for LCV formation. American Society for Microbiology 2018-12-11 /pmc/articles/PMC6299486/ /pubmed/30538188 http://dx.doi.org/10.1128/mBio.02420-18 Text en Copyright © 2018 Weber et al. https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Research Article
Weber, Stephen
Steiner, Bernhard
Welin, Amanda
Hilbi, Hubert
Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title_full Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title_fullStr Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title_full_unstemmed Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title_short Legionella-Containing Vacuoles Capture PtdIns(4)P-Rich Vesicles Derived from the Golgi Apparatus
title_sort legionella-containing vacuoles capture ptdins(4)p-rich vesicles derived from the golgi apparatus
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299486/
https://www.ncbi.nlm.nih.gov/pubmed/30538188
http://dx.doi.org/10.1128/mBio.02420-18
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