The Mla pathway in Acinetobacter baumannii has no demonstrable role in anterograde lipid transport

  1. Matthew J Powers
  2. Brent W Simpson
  3. M Stephen Trent  Is a corresponding author
  1. University of Georgia, United States

Abstract

The asymmetric outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier to the environment. Perturbations to OM lipid asymmetry sensitize the cell to antibiotics. As such, mechanisms involved in lipid asymmetry are fundamental to our understanding of OM lipid homeostasis. One such mechanism, the Maintenance of lipid asymmetry (Mla) pathway has been proposed to extract mislocalized glycerophospholipids from the outer leaflet of the OM and return them to the inner membrane (IM). Work on this pathway in Acinetobacter baumannii support conflicting models for the directionality of the Mla system being retrograde (OM to IM) or anterograde (IM to OM). Here we show conclusively that A. baumannii mla mutants exhibit no defects in anterograde transport. Furthermore, we identify an allele of the GTPase obgE that is synthetically sick in the absence of Mla; providing another link between cell envelope homeostasis and stringent response.

Data availability

Sequencing data (RNAseq) have been deposited to the database NCBI Gene Expression Omnibus. Accession number is GSE147139

The following data sets were generated

Article and author information

Author details

  1. Matthew J Powers

    Microbiology, University of Georgia, Athens, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Brent W Simpson

    Infectious Diseases, University of Georgia, Athens, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. M Stephen Trent

    Infectious Diseases, Microbiology, University of Georgia, Athens, United States
    For correspondence
    strent@uga.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6134-1800

Funding

National Institute of Allergy and Infectious Diseases (AI129940)

  • M Stephen Trent

National Institute of Allergy and Infectious Diseases (AI138576)

  • M Stephen Trent

National Institute of Allergy and Infectious Diseases (AI150098)

  • M Stephen Trent

National Science Foundation (049347-06)

  • Matthew J Powers

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

Reviewing Editor

  1. Tâm Mignot, CNRS-Aix Marseille University, France

Version history

  1. Received: March 3, 2020
  2. Accepted: September 2, 2020
  3. Accepted Manuscript published: September 3, 2020 (version 1)
  4. Version of Record published: September 18, 2020 (version 2)

Copyright

© 2020, Powers 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. Matthew J Powers
  2. Brent W Simpson
  3. M Stephen Trent
(2020)
The Mla pathway in Acinetobacter baumannii has no demonstrable role in anterograde lipid transport
eLife 9:e56571.
https://doi.org/10.7554/eLife.56571

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https://doi.org/10.7554/eLife.56571

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