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Updated: Oct 26, 2025
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Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast
Published on: February 20, 2017
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Phospho-regulated Bim1/EB1 interactions trigger Dam1c ring assembly at the budding yeast outer kinetochore
Alexander Dudziak1, Lena Engelhard2, Cole Bourque2,3
1Department of Molecular Genetics I, Center of Molecular Biotechnology, University of Duisburg-Essen, Essen, Germany.
The EMBO Journal
|July 27, 2021
Summary
Researchers discovered how the Dam1 complex (Dam1c) forms microtubule-embracing rings at kinetochores. Bim1 protein binding, regulated by phosphorylation, is crucial for Dam1c ring assembly and proper cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Kinetochores link chromosomes to the mitotic spindle.
- The Dam1 complex (Dam1c) forms microtubule-binding rings at the outer kinetochore in Saccharomyces cerevisiae.
Purpose of the Study:
- To elucidate the mechanism of Dam1c ring assembly initiation in vivo.
- To understand the role of protein interactions in kinetochore-microtubule attachment.
Main Methods:
- Electron microscopy (EM) analyses.
- Biochemical assays to study protein complex formation.
- Genetic disruption of protein interactions.
Main Results:
- Dam1c forms a stable complex with Bim1/EB1 via a Duo1 subunit motif.
- Bim1 crosslinks Dam1c heterodecamers, promoting curved oligomer formation.
- Disrupting the Dam1c-Bim1 interaction delays mitosis and impairs kinetochore localization.
- Phosphorylation enhances Dam1c-Bim1 binding and Bim1 recruits Bik1/CLIP-170.
Conclusions:
- A molecular pathway involving Bim1 controls Dam1c ring assembly during kinetochore bi-orientation.
- This pathway is essential for accurate kinetochore-microtubule attachments and error correction.
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