1. Biochemistry and Chemical Biology
  2. Cell Biology
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A sequential multi-target Mps1 phosphorylation cascade promotes spindle checkpoint signaling

  1. Zhejian Ji
  2. Haishan Gao
  3. Luying Jia
  4. Bing Li
  5. Hongtao Yu  Is a corresponding author
  1. Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, United States
Research Article
  • Cited 71
  • Views 2,818
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Cite this article as: eLife 2017;6:e22513 doi: 10.7554/eLife.22513

Abstract

The master spindle checkpoint kinase Mps1 directly senses kinetochore-microtubule attachment and promotes checkpoint signaling to ensure accurate chromosome segregation. The kinetochore scaffold Knl1, when phosphorylated by Mps1, recruits checkpoint complexes Bub1-Bub3 and BubR1-Bub3 to unattached kinetochores. Active checkpoint signaling ultimately enhances the assembly of the mitotic checkpoint complex (MCC) consisting of BubR1-Bub3, Mad2, and Cdc20, which inhibits the anaphase-promoting complex or cyclosome bound to Cdc20 (APC/CCdc20) to delay anaphase onset. Here, we show that Mps1 promotes APC/C inhibition by MCC components in vitro through phosphorylating Bub1 and Mad1. Phosphorylated Bub1 binds to Mad1-Mad2. Phosphorylated Mad1 directly interacts with Cdc20. Mutations of Mps1 phosphorylation sites in Bub1 or Mad1 abrogate the spindle checkpoint in human cells. Therefore, Mps1 promotes checkpoint activation through sequentially phosphorylating Knl1, Bub1, and Mad1. This sequential multi-target phosphorylation cascade makes the checkpoint highly responsive to Mps1 and to kinetochore-microtubule attachment.

Article and author information

Author details

  1. Zhejian Ji

    Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Haishan Gao

    Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Luying Jia

    Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Bing Li

    Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Hongtao Yu

    Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    For correspondence
    hongtao.yu@utsouthwestern.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8861-049X

Funding

Howard Hughes Medical Institute

  • Hongtao Yu

Cancer Prevention and Research Institute of Texas

  • Hongtao Yu

Welch Foundation

  • Hongtao Yu

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

Reviewing Editor

  1. Michael Rape, University of California Berkeley, United States

Publication history

  1. Received: October 19, 2016
  2. Accepted: January 9, 2017
  3. Accepted Manuscript published: January 10, 2017 (version 1)
  4. Version of Record published: January 26, 2017 (version 2)

Copyright

© 2017, Ji 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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