Microtubule Length-Regulation by Molecular Motors

TL;DR

This paper presents a stochastic model explaining how molecular motors regulate microtubule length through a balance of polymerization and motor-induced depolymerization, revealing mechanisms for achieving stable microtubule lengths.

Contribution

It introduces a new stochastic model that captures the interplay between polymerization and motor activity in microtubule length regulation.

Findings

Microtubule length depends on motor concentration and rate constants.

Collective motor phenomena lead to stable microtubule lengths.

The model predicts variance in microtubule length based on parameters.

Abstract

Length-regulation of microtubules (MTs) is essential for many cellular processes. Molecular motors like kinesin 8, which move along MTs and also act as depolymerases, are known as key players in MT dynamics. However, the regulatory mechanisms of length control remain elusive. Here, we investigate a stochastic model accounting for the interplay between polymerization kinetics and motor-induced depolymerization. We determine the dependence of MT length and variance on rate constants and motor concentration. Moreover, our analyses reveal how collective phenomena lead to a well-defined MT length.