Stable kinetochore-microtubule attachment requires loop-dependent Ndc80-Ndc80 binding.
Soumitra Polley1, Helen Müschenborn1, Melina Terbeck1
1Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
The EMBO Journal
|May 19, 2023
Summary
The Ndc80 complex
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Kinetochores connect chromosomes to spindle microtubules during cell division.
- The Ndc80 complex is essential for microtubule binding at kinetochores.
- Cooperation between adjacent Ndc80 complexes is not well understood.
Purpose of the Study:
- To investigate the role of the Ndc80 loop in Ndc80 complex interactions.
- To determine how Ndc80 complex organization affects kinetochore-microtubule attachments.
- To elucidate the contribution of Ndc80 complex interactions to cell division fidelity.
Main Methods:
- Site-directed mutagenesis of the Ndc80 loop.
- Biochemical assays to study Ndc80 complex interactions.
- Microscopy to observe kinetochore-microtubule attachments and cell division progression.
Main Results:
- The Ndc80 loop forms a rigid structure promoting interactions between Ndc80 complexes.
- Mutations in the Ndc80 loop disrupt these interactions and impair microtubule binding.
- Cells with mutated Ndc80 loops arrest in mitosis due to unstable attachments.
Conclusions:
- Loop-mediated organization of Ndc80 complexes is vital for stable kinetochore-microtubule attachments.
- This organization is critical for satisfying the spindle assembly checkpoint.
- The Ndc80 loop's function is independent of SKA complex recruitment and Ndc80 tail interactions.
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