1. Structural Biology and Molecular Biophysics

Structural basis for the phase separation of the chromosome passenger complex

  1. Nikaela W Bryan
  2. Aamir Ali
  3. Ewa Niedzialkowska
  4. Leland Mayne
  5. P Todd Stukenberg
  6. Ben E Black  Is a corresponding author
  1. University of Pennsylvania, United States
  2. University of Virginia, United States
https://doi.org/10.7554/eLife.92709
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  1. Nikaela W Bryan
  2. Aamir Ali
  3. Ewa Niedzialkowska
  4. Leland Mayne
  5. P Todd Stukenberg
  6. Ben E Black
(2024)
Structural basis for the phase separation of the chromosome passenger complex
eLife 13:e92709.
https://doi.org/10.7554/eLife.92709
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Abstract

The physical basis of phase separation is thought to consist of the same types of bonds that specify conventional macromolecular interactions yet is unsatisfyingly often referred to as 'fuzzy'. Gaining clarity on the biogenesis of membraneless cellular compartments is one of the most demanding challenges in biology. Here, we focus on the chromosome passenger complex (CPC), that forms a chromatin body that regulates chromosome segregation in mitosis. Within the three regulatory subunits of the CPC implicated in phase separation - a heterotrimer of INCENP, Survivin, and Borealin - we identify the contact regions formed upon droplet formation using hydrogen/deuterium-exchange mass spectrometry (HXMS). These contact regions correspond to some of the interfaces seen between individual heterotrimers within the crystal lattice they form. A major contribution comes from specific electrostatic interactions that can be broken and reversed through initial and compensatory mutagenesis, respectively. Our findings reveal structural insight for interactions driving liquid-liquid demixing of the CPC. Moreover, we establish HXMS as an approach to define the structural basis for phase separation.

Data availability

Source data are provided with this paper. The HXMS data in this study has been deposited in the Pride database under accession code PXD034374. The structure 2QFA [https://doi.org/10.2210/pdb2QFA/pdb] from the Protein Data Bank (www.rcsb.org) was used inthis study. An AlphaFold prediction for the Borealin protein (primary accession number Q53HL2) was used in this study.

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Author details

  1. Nikaela W Bryan

    Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5293-5145

  2. Aamir Ali

    Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Ewa Niedzialkowska

    Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Leland Mayne

    Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6969-0474

  5. P Todd Stukenberg

    Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6788-2111

  6. Ben E Black

    Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
    For correspondence
    blackbe@mail.med.upenn.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3707-9483

Funding

National Institute of General Medical Sciences (GM130302)

  • Ben E Black

National Institute of General Medical Sciences (GM134591)

  • Nikaela W Bryan

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

Copyright

© 2024, Bryan 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. Nikaela W Bryan
  2. Aamir Ali
  3. Ewa Niedzialkowska
  4. Leland Mayne
  5. P Todd Stukenberg
  6. Ben E Black
(2024)
Structural basis for the phase separation of the chromosome passenger complex
eLife 13:e92709.
https://doi.org/10.7554/eLife.92709

Share this article

https://doi.org/10.7554/eLife.92709

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