The large GTPase Sey1/atlastin mediates lipid droplet- and FadL-dependent intracellular fatty acid metabolism of Legionella pneumophila
- University of Zurich, Switzerland
- ETH Zurich, Switzerland
- Technical University of Munich, Germany
- University of Greifswald, Germany
- INSERM, University of Montpellier, France
Abstract
The amoeba-resistant bacterium Legionella pneumophila causes Legionnaires' disease and employs a type IV secretion system (T4SS) to replicate in the unique, ER-associated Legionella-containing vacuole (LCV). The large fusion GTPase Sey1/atlastin is implicated in ER dynamics, ER-derived lipid droplet (LD) formation, and LCV maturation. Here we employ cryo-electron tomography, confocal microscopy, proteomics, and isotopologue profiling to analyze LCV-LDs interactions in the genetically tractable amoeba Dictyostelium discoideum. Dually fluorescence-labeled D. discoideum producing LCV and LD markers revealed that Sey1 as well as the L. pneumophila T4SS and the Ran GTPase activator LegG1 promote LCV-LDs interactions. In vitro reconstitution using purified LCVs and LDs from parental or Dsey1 mutant D. discoideum indicated that Sey1 and GTP promote this process. Sey1 and the L. pneumophila fatty acid transporter FadL are implicated in palmitate catabolism and palmitate-dependent intracellular growth. Taken together, our results reveal that Sey1 and LegG1 mediate LD- and FadL-dependent fatty acid metabolism of intracellular L. pneumophila.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.The MS proteomics data discussed in this publication have been deposited to the ProteomeXchange Consortium via the PRIDE (Perez-Riverol et al., 2019) partner repository with the dataset identifier PXD038200
Article and author information
Author details
François Letourneur
Funding
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (31003A_175557)
- Hubert Hilbi
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (310030_207826)
- Hubert Hilbi
NOMIS Stiftung
- Martin Pilhofer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Hüsler et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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