Dwarf open reading frame (DWORF) is a direct activator of the sarcoplasmic reticulum calcium pump SERCA

  1. M'Lynn E Fisher
  2. Elisa Bovo
  3. Rodrigo Aguayo-Ortiz
  4. Ellen E Cho
  5. Marsha P Pribadi
  6. Michael P Dalton
  7. Nishadh Rathod
  8. M Joanne Lemieux
  9. L Michel Espinoza-Fonseca
  10. Seth L Robia
  11. Aleksey V Zima
  12. Howard S Young  Is a corresponding author
  1. University of Alberta, Canada
  2. Loyola University Chicago, United States
  3. University of Michigan, United States

Abstract

The sarcoplasmic reticulum calcium pump SERCA plays a critical role in the contraction-relaxation cycle of muscle. In cardiac muscle, SERCA is regulated by the inhibitor phospholamban. A new regulator, dwarf open reading frame (DWORF), has been reported to displace phospholamban from SERCA. Here, we show that DWORF is a direct activator of SERCA, increasing its turnover rate in the absence of phospholamban. Measurement of in-cell calcium dynamics supports this observation and demonstrates that DWORF increases SERCA-dependent calcium reuptake. These functional observations reveal opposing effects of DWORF activation and phospholamban inhibition of SERCA. To gain mechanistic insight into SERCA activation, fluorescence resonance energy transfer experiments revealed that DWORF has a higher affinity for SERCA in the presence of calcium. Molecular modeling and molecular dynamics simulations provide a model for DWORF activation of SERCA, where DWORF modulates the membrane bilayer and stabilizes the conformations of SERCA that predominate during elevated cytosolic calcium.

Data availability

All data generated or analyzed during this study are included in the manuscript.

Article and author information

Author details

  1. M'Lynn E Fisher

    Biochemistry, University of Alberta, Edmonton, Canada
    Competing interests
    No competing interests declared.
  2. Elisa Bovo

    Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, United States
    Competing interests
    No competing interests declared.
  3. Rodrigo Aguayo-Ortiz

    Internal Medicine, University of Michigan, Ann Arbor, United States
    Competing interests
    No competing interests declared.
  4. Ellen E Cho

    Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, United States
    Competing interests
    No competing interests declared.
  5. Marsha P Pribadi

    Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, United States
    Competing interests
    No competing interests declared.
  6. Michael P Dalton

    Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5296-5099
  7. Nishadh Rathod

    Biochemistry, University of Alberta, Edmonton, Canada
    Competing interests
    No competing interests declared.
  8. M Joanne Lemieux

    Biochemistry, University of Alberta, Edmonton, Canada
    Competing interests
    M Joanne Lemieux, Reviewing editor, eLife.
  9. L Michel Espinoza-Fonseca

    Internal Medicine, University of Michigan, Ann Arbor, United States
    Competing interests
    No competing interests declared.
  10. Seth L Robia

    Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1193-9510
  11. Aleksey V Zima

    Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, United States
    Competing interests
    No competing interests declared.
  12. Howard S Young

    Biochemistry, University of Alberta, Edmonton, Canada
    For correspondence
    hyoung@ualberta.ca
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5990-8422

Funding

National Institutes of Health (R01HL092321)

  • Seth L Robia

National Institutes of Health (R01HL092321)

  • Howard S Young

National Institutes of Health (R01HL143816)

  • Seth L Robia

National Institutes of Health (R01HL143816)

  • Howard S Young

National Institutes of Health (R01GM120142)

  • L Michel Espinoza-Fonseca

National Institutes of Health (R01HL148068)

  • L Michel Espinoza-Fonseca

National Institutes of Health (R01HL130231)

  • Aleksey V Zima

Natural Sciences and Engineering Research Council of Canada (RGPIN-2016-06478)

  • M Joanne Lemieux

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

Reviewing Editor

  1. Mark T Nelson, University of Vermont, United States

Publication history

  1. Received: December 7, 2020
  2. Accepted: June 1, 2021
  3. Accepted Manuscript published: June 2, 2021 (version 1)
  4. Version of Record published: June 14, 2021 (version 2)

Copyright

© 2021, Fisher 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. M'Lynn E Fisher
  2. Elisa Bovo
  3. Rodrigo Aguayo-Ortiz
  4. Ellen E Cho
  5. Marsha P Pribadi
  6. Michael P Dalton
  7. Nishadh Rathod
  8. M Joanne Lemieux
  9. L Michel Espinoza-Fonseca
  10. Seth L Robia
  11. Aleksey V Zima
  12. Howard S Young
(2021)
Dwarf open reading frame (DWORF) is a direct activator of the sarcoplasmic reticulum calcium pump SERCA
eLife 10:e65545.
https://doi.org/10.7554/eLife.65545

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