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Updated: Apr 2, 2026
07:47
Directly Measuring Forces Within Reconstituted Active Microtubule Bundles
Published on: May 10, 2022
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Minimal model for collective kinetochore-microtubule dynamics
Edward J Banigan1, Kevin K Chiou2, Edward R Ballister3
1Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208; Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104;
Summary
A new model explains how kinetochore-microtubule dynamics ensure accurate chromosome segregation. Kinetochore phosphorylation by Aurora B kinase corrects errors by promoting microtubule shortening, preventing chromosome mis-segregation.
Area of Science:
- Cell biology
- Biophysics
- Molecular dynamics
Background:
- Chromosome segregation relies on kinetochore-microtubule interactions.
- The collective behavior of multiple microtubules (MTs) attached to a single kinetochore is not fully understood.
Purpose of the Study:
- To develop a minimal model for collective kinetochore-MT dynamics.
- To investigate the role of Aurora B kinase phosphorylation in regulating these dynamics.
Main Methods:
- Developed a minimal theoretical model based on in vitro measurements.
- Incorporated force-velocity relationships and Aurora B kinase phosphorylation.
- Validated the model with experiments using chemically induced dimerization to enhance Aurora B activity.
Main Results:
- The model predicts a bistable force-velocity relation for coupled MTs, allowing rapid shortening or slow growth.
- Bistability and speed differences cause oscillations in sister kinetochore pairs.
- Aurora B phosphorylation shifts bistability, promoting rapid shortening and error correction at low tension.
Conclusions:
- The minimal model captures key kinetochore-MT dynamics.
- Phosphorylation acts as a biochemical signal to regulate MT dynamics and ensure accurate chromosome segregation.
- The model provides a framework for understanding in vivo kinetochore-MT regulation.
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