Ion-mediated condensation controls the mechanics of mitotic chromosomes
During mitosis in eukaryotic cells, mechanical forces generated by the mitotic spindle pull the sister chromatids into the nascent daughter cells. How do mitotic chromosomes achieve the necessary mechanical stiffness and stability to maintain their integrity under these forces? Here we use optical tweezers to show that ions involved in physiological chromosome condensation are crucial for chromosomal stability, stiffness and viscous dissipation. We combine these experiments with high-salt histone depletion and theory to show that chromosomal elasticity originates from the chromatin fibre behaving as a flexible polymer, whereas energy dissipation can be explained by modelling chromatin loops as an entangled polymer solution. Taken together, we show how collective properties of mitotic chromosomes, a biomaterial of incredible complexity, emerge from molecular properties, and how they are controlled by the physico-chemical environment.
Authors
- Gijs J. L. Wuite (ORCID: https://orcid.org/0000-0002-5706-043X)
- Christian Friberg Nielsen (ORCID: https://orcid.org/0000-0002-2886-317X)
- Janni Harju (ORCID: https://orcid.org/0000-0001-9696-5453)
- Charlotte M.A. Bruinsma
- Erwin J.G. Peterman (ORCID: https://orcid.org/0000-0003-1058-249X)
- Tinka V M Clement (ORCID: https://orcid.org/0000-0002-6590-2852)
- Emma M.J. Chameau
- Ian D. Hickson (ORCID: https://orcid.org/0000-0002-0583-566X)
- Chase P. Broedersz (ORCID: https://orcid.org/0000-0001-7283-3704)
- Hannes Witt (ORCID: https://orcid.org/0000-0001-8785-8293)
Institutions
- University of Copenhagen (DK)
- Center for NanoScience (DE)
- Center for Theoretical Physics (PL)
- Ludwig-Maximilians-Universität München (DE)
- Vrije Universiteit Amsterdam (NL)
Publication Details
- Journal
- Nature Materials
- Published
- 2024-09-16
- DOI
- https://doi.org/10.1038/s41563-024-01975-0
- Citations
- 7
- Primary Topic
- Microtubule and mitosis dynamics
- Type
- article
- Field-Weighted Citation Impact
- 1.96
Funders
- European Commission
- National Research Foundation
- Deutsche Forschungsgemeinschaft
- Danmarks Grundforskningsfond
- Novo Nordisk
- Nordea-fonden
- Novo Nordisk Fonden
- Horizon 2020 Framework Programme