Conformational mechanism for the stability of microtubule-kinetochore attachments

TL;DR

This paper presents a mechanical model explaining how the geometry of microtubule protofilaments influences kinetochore attachment stability, providing insights into chromosome segregation during cell division.

Contribution

It introduces a novel mechanical model linking protofilament geometry to attachment stability, validated by reproducing experimental detachment times.

Findings

Protofilament geometry affects attachment stability.

Model accurately reproduces yeast kinetochore detachment times.

Geometrical features may regulate attachment switching.

Abstract

Regulating the stability of microtubule(MT)-kinetochore attachments is fundamental to avoiding mitotic errors and ensure proper chromosome segregation during cell division. While biochemical factors involved in this process have been identified, its mechanics still needs to be better understood. Here we introduce and simulate a mechanical model of MT-kinetochore interactions in which the stability of the attachment is ruled by the geometrical conformations of curling MT-protofilaments entangled in kinetochore fibrils. The model allows us to reproduce with good accuracy in vitro experimental measurements of the detachment times of yeast kinetochores from MTs under external pulling forces. Numerical simulations suggest that geometrical features of MT-protofilaments may play an important role in the switch between stable and unstable attachments.