Reconstitution of surface lipoprotein translocation through the slam translocon

  1. Minh Sang Huynh
  2. Yogesh Hooda
  3. Yuzi Raina Li
  4. Maciej Jagielnicki
  5. Christine Chieh-Lin Lai
  6. Trevor F Moraes  Is a corresponding author
  1. University of Toronto, Canada
  2. University of Cambridge, United Kingdom

Abstract

Surface lipoproteins (SLPs) are peripherally attached to the outer leaflet of the outer membrane in many Gram-negative bacteria, playing significant roles in nutrient acquisition and immune evasion in the host. While the factors that are involved in the synthesis and delivery of SLPs in the inner membrane are well characterized, the molecular machinery required for the movement of SLPs to the surface are still not fully elucidated. In this study, we investigated the translocation of a surface lipoprotein TbpB through a Slam1-dependent pathway. Using purified components, we developed an in vitro translocation assay where unfolded TbpB is transported through Slam1 containing proteoliposomes, confirming Slam1 as an outer membrane translocon. While looking to identify factors to increase translocation efficiency, we discovered the periplasmic chaperone Skp interacted with TbpB in the periplasm of Escherichia coli. The presence of Skp was found to increase the translocation efficiency of TbpB in the reconstituted translocation assays. A knockout of Skp in Neisseria meningitidis revealed that Skp is essential for functional translocation of TbpB to the bacterial surface. Taken together, we propose a pathway for surface destined lipoproteins, where Skp acts as a holdase for Slam-mediated TbpB translocation across the outer membrane.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files

Article and author information

Author details

  1. Minh Sang Huynh

    Department of Biochemistry, University of Toronto, Toronto, Canada
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9541-6441
  2. Yogesh Hooda

    MRC Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
    Competing interests
    Yogesh Hooda, is a co-author on a patent, 'Slam polynucleotides and polypeptides and uses thereof' - patent number WO2017136947A1..
  3. Yuzi Raina Li

    Department of Biochemistry, University of Toronto, Toronto, Canada
    Competing interests
    No competing interests declared.
  4. Maciej Jagielnicki

    Department of Biochemistry, University of Toronto, Toronto, Canada
    Competing interests
    No competing interests declared.
  5. Christine Chieh-Lin Lai

    Department of Biochemistry, University of Toronto, Toronto, Canada
    Competing interests
    Christine Chieh-Lin Lai, is a co-author on a patent, 'Slam polynucleotides and polypeptides and uses thereof' - patent number WO2017136947A1..
  6. Trevor F Moraes

    Department of Biochemistry, University of Toronto, Toronto, Canada
    For correspondence
    trevor.moraes@utoronto.ca
    Competing interests
    Trevor F Moraes, is a co-author on a patent, 'Slam polynucleotides and polypeptides and uses thereof' - patent number WO2017136947A1..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9883-6145

Funding

Canadian Institutes of Health Research (PJT-148795)

  • Trevor F Moraes

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Heedeok Hong, Michigan State University, United States

Version history

  1. Received: August 5, 2021
  2. Preprint posted: August 23, 2021 (view preprint)
  3. Accepted: April 26, 2022
  4. Accepted Manuscript published: April 27, 2022 (version 1)
  5. Version of Record published: May 10, 2022 (version 2)

Copyright

© 2022, Huynh 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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  1. Minh Sang Huynh
  2. Yogesh Hooda
  3. Yuzi Raina Li
  4. Maciej Jagielnicki
  5. Christine Chieh-Lin Lai
  6. Trevor F Moraes
(2022)
Reconstitution of surface lipoprotein translocation through the slam translocon
eLife 11:e72822.
https://doi.org/10.7554/eLife.72822

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