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Updated: Feb 13, 2026
05:35
Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
Published on: March 3, 2016
15.7K
Unattached kinetochores drive their own capturing by sequestering a CLASP
Caroline Kolenda1, Jennifer Ortiz1, Marina Pelzl1
1Biochemie-Zentrum der Universität Heidelberg, INF 328, 69120, Heidelberg, Germany.
Nature Communications
|March 2, 2018
Summary
Unattached kinetochores promote their own capture by sequestering Stu1, which disrupts spindle organization. This creates dynamic microtubules ideal for capturing, ensuring accurate chromosome segregation.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- The spindle assembly checkpoint (SAC) prevents chromosome missegregation by sensing unattached kinetochores.
- Kinetochore-microtubule attachment is crucial for accurate chromosome segregation during cell division.
Purpose of the Study:
- To investigate the mechanisms by which unattached kinetochores promote their own capture by microtubules.
- To elucidate the role of Stu1 and its regulation in kinetochore capture and spindle organization.
Main Methods:
- Phosphorylation assays to study Spc105 modification by Mps1.
- Immunofluorescence microscopy to visualize kinetochore and microtubule dynamics.
- Genetic manipulation to assess the function of Stu1 and Slk19.
Main Results:
- Mps1-mediated phosphorylation of Spc105 at unattached kinetochores facilitates Stu1 sequestration with Slk19.
- Stu1 withdrawal from microtubules disrupts spindle organization, promoting dynamic random microtubule formation.
- This enhanced microtubule dynamics increases the efficiency of unattached kinetochore capture.
- Post-capture, Stu1 stabilizes microtubule attachments, preventing premature depolymerization.
Conclusions:
- Unattached kinetochores actively promote their capture through a mechanism involving Stu1 sequestration and spindle disruption.
- Stu1 plays a dual role in kinetochore capture and maintaining spindle integrity during chromosome segregation.
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