1. Structural Biology and Molecular Biophysics
  2. Cell Biology
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Non-catalytic motor domains enable processive movement and functional diversification of the kinesin-14 Kar3

Research Article
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Cite this article as: eLife 2015;4:e04489 doi: 10.7554/eLife.04489

Abstract

Motors proteins of the conserved kinesin-14 family have important roles in mitotic spindle organization and chromosome segregation. Previous studies have indicated that kinesin-14 motors are non-processive enzymes, working in the context of multi-motor ensembles that collectively organize microtubule networks. Here we show that the yeast kinesin-14 Kar3 generates processive movement as a heterodimer with the non-motor proteins Cik1 or Vik1. By analyzing the single-molecule properties of engineered motors we demonstrate that the non-catalytic domain has a key role in the motility mechanism by acting as a 'foothold' that allows Kar3 to bias translocation towards the minus end. This mechanism rivals the speed and run length of conventional motors, can support transport of the Ndc80 complex in vitro and is critical for Kar3 function in vivo. Our findings provide an example for a non-conventional translocation mechanism and can explain how Kar3 substitutes for key functions of Dynein in the yeast nucleus.

Article and author information

Author details

  1. Christine Mieck

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  2. Maxim I Molodtsov

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  3. Katarzyna Drzewicka

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  4. Babet van der Vaart

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  5. Gabriele Litos

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  6. Gerald Schmauss

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  7. Alipasha Vaziri

    Research Institute of Molecular Pathology, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  8. Stefan Westermann

    Research Institute of Molecular Pathology, Vienna, Austria
    For correspondence
    westermann@imp.ac.at
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Stephen C Harrison, Howard Hughes Medical Institute, Harvard Medical School, United States

Publication history

  1. Received: August 23, 2014
  2. Accepted: January 26, 2015
  3. Accepted Manuscript published: January 27, 2015 (version 1)
  4. Version of Record published: February 24, 2015 (version 2)

Copyright

© 2015, Mieck 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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