Kinetochores attached to microtubule-ends are stabilised by Astrin bound PP1 to ensure proper chromosome segregation
- Queen Mary University of London, United Kingdom
Abstract
Microtubules segregate chromosomes by attaching to macromolecular kinetochores. Only microtubule-end attached kinetochores can be pulled apart; how these end-on attachments are selectively recognised and stabilised is not known. Using the kinetochore and microtubule-associated protein, Astrin, as a molecular probe, we show that end-on attachments are rapidly stabilised by spatially-restricted delivery of PP1 near the C-terminus of Ndc80, a core kinetochore-microtubule linker. PP1 is delivered by the evolutionarily conserved tail of Astrin and this promotes Astrin's own enrichment creating a highly-responsive positive feedback, independent of biorientation. Abrogating Astrin:PP1-delivery disrupts attachment stability, which is not rescued by inhibiting Aurora-B, an attachment destabiliser, but is reversed by artificially tethering PP1 near the C-terminus of Ndc80. Constitutive Astrin:PP1-delivery disrupts chromosome congression and segregation, revealing a dynamic mechanism for stabilising attachments. Thus, Astrin-PP1 mediates a dynamic 'lock' that selectively and rapidly stabilises end-on attachments, independent of biorientation, and ensures proper chromosome segregation.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Funding
Queen Mary University of London (SBC8DRA2)
- Viji M Draviam
Biotechnology and Biological Sciences Research Council (R01003X/1)
- Viji M Draviam
Cancer Research UK (C28598/A9787)
- Viji M Draviam
Medical Research Council (MR/K50127X/1)
- Duccio Conti
Islamic Development Bank
- Parveen Gul
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Jennifer G. DeLuca, Colorado State University, United States
Version history
- Received: June 14, 2019
- Accepted: December 1, 2019
- Accepted Manuscript published: December 6, 2019 (version 1)
- Version of Record published: December 24, 2019 (version 2)
Copyright
© 2019, Conti 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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Kinetochores attached to microtubule-ends are stabilised by Astrin bound PP1 to ensure proper chromosome segregation
eLife 8:e49325.
https://doi.org/10.7554/eLife.49325
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