Tension directly stabilizes reconstituted kinetochore-microtubule attachments
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- 24 November 2010
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 468 (7323), 576-579
- https://doi.org/10.1038/nature09594
Abstract
The kinetochore is the large protein complex that assembles on centromeric DNA to mediate chromosome separation. For decades, researchers have tried to isolate whole functional kinetochores without success. Sue Biggins and colleagues now report the first purification of functional kinetochores. They also show that kinetochore particles maintain load-bearing associations with assembling and disassembling microtubules, and that tension directly increases the lifetimes of the attachments. These results provide evidence that tension selectively stabilizes kinetochore–microtubule interactions. The kinetochore is a large protein complex that assembles on centromeric DNA and captures microtubules to mediate chromosome separation. These authors report the first purification of functional kinetochores. They also show that kinetochore particles maintain load-bearing associations with assembling and disassembling ends of single microtubules and that tension increases the lifetimes of the attachments directly. These results provide evidence that tension selectively stabilises kinetochore–microtubule interactions. Kinetochores are macromolecular machines that couple chromosomes to dynamic microtubule tips during cell division, thereby generating force to segregate the chromosomes1,2. Accurate segregation depends on selective stabilization of correct ‘bi-oriented’ kinetochore–microtubule attachments, which come under tension as the result of opposing forces exerted by microtubules3. Tension is thought to stabilize these bi-oriented attachments indirectly, by suppressing the destabilizing activity of a kinase, Aurora B4,5. However, a complete mechanistic understanding of the role of tension requires reconstitution of kinetochore–microtubule attachments for biochemical and biophysical analyses in vitro. Here we show that native kinetochore particles retaining the majority of kinetochore proteins can be purified from budding yeast and used to reconstitute dynamic microtubule attachments. Individual kinetochore particles maintain load-bearing associations with assembling and disassembling ends of single microtubules for >30 min, providing a close match to the persistent coupling seen in vivo between budding yeast kinetochores and single microtubules6. Moreover, tension increases the lifetimes of the reconstituted attachments directly, through a catch bond-like mechanism that does not require Aurora B7,8,9,10. On the basis of these findings, we propose that tension selectively stabilizes proper kinetochore–microtubule attachments in vivo through a combination of direct mechanical stabilization and tension-dependent phosphoregulation.Keywords
This publication has 39 references indexed in Scilit:
- Direct physical study of kinetochore–microtubule interactions by reconstitution and interrogation with an optical force clampMethods, 2010
- Cooperation of the Dam1 and Ndc80 kinetochore complexes enhances microtubule coupling and is regulated by aurora BThe Journal of cell biology, 2010
- Reconstitution and Functional Analysis of Kinetochore SubcomplexesMethods in cell biology, 2010
- The life and miracles of kinetochoresThe EMBO Journal, 2009
- The Ndc80 Kinetochore Complex Forms Load-Bearing Attachments to Dynamic Microtubule Tips via Biased DiffusionCell, 2009
- Kinetochore–microtubule interaction during S phase in Saccharomyces cerevisiaeGenes & Development, 2007
- Tension applied through the Dam1 complex promotes microtubule elongation providing a direct mechanism for length control in mitosisNature, 2007
- The Conserved KMN Network Constitutes the Core Microtubule-Binding Site of the KinetochoreCell, 2006
- The Dam1 kinetochore complex harnesses microtubule dynamics to produce force and movementProceedings of the National Academy of Sciences of the United States of America, 2006
- Analysis of the Saccharomyces Spindle Pole by Matrix-assisted Laser Desorption/Ionization (MALDI) Mass SpectrometryThe Journal of cell biology, 1998