1. Cell Biology
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A novel isoform of MAP4 organises the paraxial microtubule array required for muscle cell differentiation

  1. Binyam Mogessie
  2. Daniel Roth
  3. Zainab Rahil
  4. Anne Straube  Is a corresponding author
  1. University of Warwick, United Kingdom
  2. University of Illinois, United States
Research Article
  • Cited 28
  • Views 3,312
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Cite this article as: eLife 2015;4:e05697 doi: 10.7554/eLife.05697

Abstract

The microtubule cytoskeleton is critical for muscle cell differentiation and undergoes reorganisation into an array of paraxial microtubules, which serves as template for contractile sarcomere formation. Here, we identify a previously uncharacterised isoform of microtubule-associated protein MAP4, oMAP4, as a microtubule organising factor that is crucial for myogenesis. We show that oMAP4 is expressed upon muscle cell differentiation and is the only MAP4 isoform essential for normal progression of the myogenic differentiation programme. Depletion of oMAP4 impairs cell elongation and cell-cell fusion. Most notably, oMAP4 is required for paraxial microtubule organisation in muscle cells and prevents dynein- and kinesin-driven microtubule-microtubule sliding. Purified oMAP4 aligns dynamic microtubules into antiparallel bundles that withstand motor forces in vitro. We propose a model in which the cooperation of dynein-mediated microtubule transport and oMAP4-mediated zippering of microtubules drives formation of a paraxial microtubule array that provides critical support for the polarisation and elongation of myotubes.

Article and author information

Author details

  1. Binyam Mogessie

    Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  2. Daniel Roth

    Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  3. Zainab Rahil

    Department of Chemical and Biomolecular Engineering, University of Illinois, Champaign, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Anne Straube

    Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry, United Kingdom
    For correspondence
    anne@mechanochemistry.org
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Anna Akhmanova, Utrecht University, Netherlands

Publication history

  1. Received: November 20, 2014
  2. Accepted: April 19, 2015
  3. Accepted Manuscript published: April 21, 2015 (version 1)
  4. Accepted Manuscript updated: April 28, 2015 (version 2)
  5. Version of Record published: May 7, 2015 (version 3)

Copyright

© 2015, Mogessie 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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