Aging of dynamically stabilized microtubules

TL;DR

This paper introduces a model for microtubule aging behavior influenced by rescue factors, highlighting the impact of cell geometry on microtubule dynamics and providing a way to test different hypotheses about rescue mechanisms.

Contribution

It presents a novel dynamic rescue model for microtubules that predicts aging behavior, offering experimental testability to distinguish between existing hypotheses.

Findings

Microtubules exhibit aging behavior due to rescue factor dynamics.

Cell geometry significantly affects microtubule stability predictions.

The model provides a framework to experimentally test rescue mechanisms.

Abstract

The microtubule network, an important part of the cytoskeleton, is constantly remodeled by alternating phases of growth and shrinkage of individual filaments. Plus-end tracking proteins (+TIPs) interact with the microtubule and in many cases alter its dynamics. While it is established that the prototypal CLIP-170 enhances microtubule stability by increasing rescues, the plus-end tracking mechanism is still under debate. We present a model for microtubule dynamics in which a rescue factor is dynamically added to the filament while growing. As a consequence, the filament shows aging behavior which should be experimentally accessible and thus allow one to exclude some hypothesized models of the inclusion of rescue factors at the microtubule plus end. Additionally, we show the strong influence of the cell geometry on the quantitative results.