1. Structural Biology and Molecular Biophysics
  2. Cell Biology

Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips

  1. Jonathan W Driver
  2. Elisabeth A Geyer
  3. Megan E Bailey
  4. Luke M Rice  Is a corresponding author
  5. Charles L Asbury  Is a corresponding author
  1. University of Washington, United States
  2. University of Texas Southwestern Medical Center, United States
https://doi.org/10.7554/eLife.28433
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  1. Jonathan W Driver
  2. Elisabeth A Geyer
  3. Megan E Bailey
  4. Luke M Rice
  5. Charles L Asbury
(2017)
Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips
eLife 6:e28433.
https://doi.org/10.7554/eLife.28433
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Abstract

Disassembling microtubules can generate movement independently of motor enzymes, especially at kinetochores where they drive chromosome motility. A popular explanation is the 'conformational wave' model, in which protofilaments pull on the kinetochore as they curl outward from a disassembling tip. But whether protofilaments can work efficiently via this spring-like mechanism has been unclear. By modifying a previous assay to use recombinant tubulin and feedback-controlled laser trapping, we directly demonstrate the spring-like elasticity of curling protofilaments. Measuring their mechanical work output suggests they carry ~25% of the energy of GTP hydrolysis as bending strain, enabling them to drive movement with efficiency similar to conventional motors. Surprisingly, a β-tubulin mutant that dramatically slows disassembly has no effect on work output, indicating an uncoupling of disassembly speed from protofilament strain. These results show the wave mechanism can make a major contribution to kinetochore motility and establish a direct approach for measuring tubulin mechano-chemistry.

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Author details

  1. Jonathan W Driver

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Elisabeth A Geyer

    Department of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Megan E Bailey

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Luke M Rice

    Department of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
    For correspondence
    Luke.Rice@UTSouthwestern.edu
    Competing interests
    The authors declare that no competing interests exist.

  5. Charles L Asbury

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    For correspondence
    casbury@uw.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0143-5394

Funding

Sackler Scholars Program in Integrative Biophysics

  • Jonathan W Driver

Leukemia and Lymphoma Society

  • Jonathan W Driver

National Institutes of Health (T32CA080416)

  • Megan E Bailey

Packard Foundation (2006‐30521)

  • Charles L Asbury

NSF Graduate Research Fellowship (2014177758)

  • Elisabeth A Geyer

National Institutes of Health (RO1GM098543)

  • Luke M Rice

NSF Career Award (MCB1054947)

  • Luke M Rice

National Institutes of Health (RO1GM079373)

  • Charles L Asbury

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

Copyright

© 2017, Driver 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. Jonathan W Driver
  2. Elisabeth A Geyer
  3. Megan E Bailey
  4. Luke M Rice
  5. Charles L Asbury
(2017)
Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips
eLife 6:e28433.
https://doi.org/10.7554/eLife.28433

Share this article

https://doi.org/10.7554/eLife.28433

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