The large GTPase Sey1/atlastin mediates lipid droplet- and FadL-dependent intracellular fatty acid metabolism of Legionella pneumophila

  1. Dario Hüsler
  2. Pia Stauffer
  3. Bernhard Keller
  4. Desirée Böck
  5. Thomas Steiner
  6. Anne Ostrzinski
  7. Simone Vormittag
  8. Bianca Striednig
  9. A Leoni Swart
  10. François Letourneur
  11. Sandra Maaß
  12. Dörte Becher
  13. Wolfgang Eisenreich
  14. Martin Pilhofer
  15. Hubert Hilbi  Is a corresponding author
  1. University of Zurich, Switzerland
  2. ETH Zurich, Switzerland
  3. Technical University of Munich, Germany
  4. University of Greifswald, Germany
  5. 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

The following data sets were generated

Article and author information

Author details

  1. Dario Hüsler

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  2. Pia Stauffer

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  3. Bernhard Keller

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  4. Desirée Böck

    Institute of Molecular Biology and Biophysics, ETH Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  5. Thomas Steiner

    Bavarian NMR Center - Structural Membrane Biochemistry, Technical University of Munich, Garching, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Anne Ostrzinski

    Institute of Microbiology, University of Greifswald, Greifswald, Germany
    Competing interests
    The authors declare that no competing interests exist.
  7. Simone Vormittag

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  8. Bianca Striednig

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7575-8965
  9. A Leoni Swart

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  10. François Letourneur

    INSERM, University of Montpellier, Montpellier, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2232-6127
  11. Sandra Maaß

    Institute of Microbiology, University of Greifswald, Greifswald, Germany
    Competing interests
    The authors declare that no competing interests exist.
  12. Dörte Becher

    Institute for Microbiology, University of Greifswald, Greifswald, Germany
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9630-5735
  13. Wolfgang Eisenreich

    Bavarian NMR Center - Structural Membrane Biochemistry, Technical University of Munich, Garching, Germany
    Competing interests
    The authors declare that no competing interests exist.
  14. Martin Pilhofer

    Institute of Molecular Biology and Biophysics, ETH Zurich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  15. Hubert Hilbi

    Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
    For correspondence
    hilbi@imm.uzh.ch
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5462-9301

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.

Metrics

  • 760
    views
  • 146
    downloads
  • 9
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

Share this article

https://doi.org/10.7554/eLife.85142

Further reading

    1. Immunology and Inflammation
    2. Microbiology and Infectious Disease
    Ainhoa Arbués, Sarah Schmidiger ... Damien Portevin
    Research Article

    The members of the Mycobacterium tuberculosis complex (MTBC) causing human tuberculosis comprise 10 phylogenetic lineages that differ in their geographical distribution. The human consequences of this phylogenetic diversity remain poorly understood. Here, we assessed the phenotypic properties at the host-pathogen interface of 14 clinical strains representing five major MTBC lineages. Using a human in vitro granuloma model combined with bacterial load assessment, microscopy, flow cytometry, and multiplexed-bead arrays, we observed considerable intra-lineage diversity. Yet, modern lineages were overall associated with increased growth rate and more pronounced granulomatous responses. MTBC lineages exhibited distinct propensities to accumulate triglyceride lipid droplets—a phenotype associated with dormancy—that was particularly pronounced in lineage 2 and reduced in lineage 3 strains. The most favorable granuloma responses were associated with strong CD4 and CD8 T cell activation as well as inflammatory responses mediated by CXCL9, granzyme B, and TNF. Both of which showed consistent negative correlation with bacterial proliferation across genetically distant MTBC strains of different lineages. Taken together, our data indicate that different virulence strategies and protective immune traits associate with MTBC genetic diversity at lineage and strain level.

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease
    Eva Herdering, Tristan Reif-Trauttmansdorff ... Ruth Anne Schmitz
    Research Article

    Glutamine synthetases (GS) are central enzymes essential for the nitrogen metabolism across all domains of life. Consequently, they have been extensively studied for more than half a century. Based on the ATP-dependent ammonium assimilation generating glutamine, GS expression and activity are strictly regulated in all organisms. In the methanogenic archaeon Methanosarcina mazei, it has been shown that the metabolite 2-oxoglutarate (2-OG) directly induces the GS activity. Besides, modulation of the activity by interaction with small proteins (GlnK1 and sP26) has been reported. Here, we show that the strong activation of M. mazei GS (GlnA1) by 2-OG is based on the 2-OG dependent dodecamer assembly of GlnA1 by using mass photometry (MP) and single particle cryo-electron microscopy (cryo-EM) analysis of purified strep-tagged GlnA1. The dodecamer assembly from dimers occurred without any detectable intermediate oligomeric state and was not affected in the presence of GlnK1. The 2.39 Å cryo-EM structure of the dodecameric complex in the presence of 12.5 mM 2-OG demonstrated that 2-OG is binding between two monomers. Thereby, 2-OG appears to induce the dodecameric assembly in a cooperative way. Furthermore, the active site is primed by an allosteric interaction cascade caused by 2-OG-binding towards an adaption of an open active state conformation. In the presence of additional glutamine, strong feedback inhibition of GS activity was observed. Since glutamine dependent disassembly of the dodecamer was excluded by MP, feedback inhibition most likely relies on the binding of glutamine to the catalytic site. Based on our findings, we propose that under nitrogen limitation the induction of M. mazei GS into a catalytically active dodecamer is not affected by GlnK1 and crucially depends on the presence of 2-OG.