1. Cell Biology

Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit

  1. James Holder  Is a corresponding author
  2. Shabaz Mohammed
  3. Francis A Barr  Is a corresponding author
  1. University of Oxford, United Kingdom
https://doi.org/10.7554/eLife.59885
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  1. James Holder
  2. Shabaz Mohammed
  3. Francis A Barr
(2020)
Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit
eLife 9:e59885.
https://doi.org/10.7554/eLife.59885
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Abstract

APC/C-mediated proteolysis of cyclin B and securin promotes anaphase entry, inactivating CDK1 and permitting chromosome segregation, respectively. Reduction of CDK1 activity relieves inhibition of the CDK1-counteracting phosphatases PP1 and PP2A-B55, allowing wide-spread dephosphorylation of substrates. Meanwhile, continued APC/C activity promotes proteolysis of other mitotic regulators. Together, these activities orchestrate a complex series of events during mitotic exit. However, the relative importance of regulated proteolysis and dephosphorylation in dictating the order and timing of these events remains unclear. Using high temporal-resolution proteomics, we compare the relative extent of proteolysis and protein dephosphorylation. This reveals highly-selective rapid proteolysis of cyclin B, securin and geminin at the metaphase-anaphase transition, followed by slow proteolysis of other substrates. Dephosphorylation requires APC/C-dependent destruction of cyclin B and was resolved into PP1-dependent categories with unique sequence motifs. We conclude that dephosphorylation initiated by selective proteolysis of cyclin B drives the bulk of changes observed during mitotic exit.

Data availability

Source data files have been provided for Figures 2, 3, 6 and 7. These include a processed form of the raw data, where some extraneous metadata has been removed.Full raw data is available at PRIDE with the following accession numbers: FIgure 2 Total Proteome PXD019791, Figure 2 Phospho-proteome PXD019788, Figure 3 PXD019795, Figure 6 PXD019787, Figure 7 PXD019786

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. James Holder

    Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
    For correspondence
    james.holder@path.ox.ac.uk
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7597-3104

  2. Shabaz Mohammed

    Biochemistry Department, University of Oxford, Oxford, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.

  3. Francis A Barr

    Department of Biochemistry, University of Oxford, Oxford, United Kingdom
    For correspondence
    francis.barr@bioch.ox.ac.uk
    Competing interests
    The authors declare that no competing interests exist.

Funding

Cancer Research UK (Program Grant)

  • James Holder
  • Francis A Barr

Wellcome (PhD Award)

  • James Holder

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

Reviewing Editor

  1. Adèle L Marston, University of Edinburgh, United Kingdom

Publication history

  1. Received: June 11, 2020
  2. Accepted: August 31, 2020
  3. Accepted Manuscript published: September 1, 2020 (version 1)
  4. Version of Record published: October 1, 2020 (version 2)
  5. Version of Record updated: October 5, 2020 (version 3)

Copyright

© 2020, Holder 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. James Holder
  2. Shabaz Mohammed
  3. Francis A Barr
(2020)
Ordered dephosphorylation initiated by the selective proteolysis of cyclin B drives mitotic exit
eLife 9:e59885.
https://doi.org/10.7554/eLife.59885

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