1. Biochemistry and Chemical Biology
  2. Structural Biology and Molecular Biophysics
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Serine phosphorylation regulates the P-type potassium pump KdpFABC

  1. Marie E Sweet
  2. Xihui Zhang
  3. Hediye Erdjument-Bromage
  4. Vikas Dubey
  5. Himanshu Khandelia
  6. Thomas A Neubert
  7. Bjorn P Pedersen
  8. David L Stokes  Is a corresponding author
  1. NYU School of Medicine, United States
  2. University of Southern Denmark, Denmark
  3. Aarhus University, Denmark
Research Article
  • Cited 4
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Cite this article as: eLife 2020;9:e55480 doi: 10.7554/eLife.55480

Abstract

KdpFABC is an ATP-dependent K+ pump that ensures bacterial survival in K+-deficient environments. Whereas transcriptional activation of kdpFABC expression is well studied, a mechanism for down regulation when K+ levels are restored has not been described. Here we show that KdpFABC is inhibited when cells return to a K+-rich environment. The mechanism of inhibition involves phosphorylation of Ser162 on KdpB, which can be reversed in vitro by treatment with serine phosphatase. Mutating Ser162 to Alanine produces constitutive activity, whereas the phosphomimetic Ser162Asp mutation inactivates the pump. Analyses of the transport cycle show that serine phosphorylation abolishes the K+-dependence of ATP hydrolysis and blocks the catalytic cycle after formation of the aspartyl phosphate intermediate (E1~P). This regulatory mechanism is unique amongst P-type pumps and this study furthers our understanding of how bacteria control potassium homeostasis to maintain cell volume and osmotic potential.

Data availability

Raw mass spectrometry files have been deposited to the MassIVE database under accession code MSV000084906

The following data sets were generated

Article and author information

Author details

  1. Marie E Sweet

    Skirball Institute, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Xihui Zhang

    Skirball Institute, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Hediye Erdjument-Bromage

    Skirball Institute, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Vikas Dubey

    University of Southern Denmark, Odense, Denmark
    Competing interests
    The authors declare that no competing interests exist.
  5. Himanshu Khandelia

    University of Southern Denmark, Odense, Denmark
    Competing interests
    The authors declare that no competing interests exist.
  6. Thomas A Neubert

    Skirball Institute, NYU School of Medicine, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Bjorn P Pedersen

    Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
    Competing interests
    The authors declare that no competing interests exist.
  8. David L Stokes

    Skirball Institute, NYU School of Medicine, New York, United States
    For correspondence
    stokes@nyu.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5455-8163

Funding

National Institutes of Health (R01 GM108043)

  • David L Stokes

National Institutes of Health (S10 RR027990)

  • Thomas A Neubert

European Research Council (637372)

  • Bjorn P Pedersen

Independent Research Fund Denmark (DFF-8021-00161)

  • Bjorn P Pedersen

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

Reviewing Editor

  1. Lucy R Forrest, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States

Publication history

  1. Received: January 25, 2020
  2. Accepted: September 19, 2020
  3. Accepted Manuscript published: September 21, 2020 (version 1)
  4. Version of Record published: October 5, 2020 (version 2)

Copyright

© 2020, Sweet 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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