Driven diffusive systems of active filament bundles

TL;DR

This paper introduces a new class of driven diffusive models to study active filament bundles in the cytoskeleton, analyzing their dynamics, phase behavior, and conditions for filament condensation.

Contribution

It presents a novel modeling framework for active filament systems, including exact solutions and mean-field analysis linking filament tension to system dynamics.

Findings

Exact solution reveals filament condensation phenomena.

Mean-field analysis identifies conditions for phase transitions.

Hopping rates are related to tension in the filament bundle.

Abstract

The cytoskeleton is an important subsystem of cells that is involved for example in cell division and locomotion. It consists of filaments that are cross-linked by molecular motors that can induce relative sliding between filaments and generate stresses in the network. In order to study the effects of fluctuations on the dynamics of such a system we introduce here a new class of driven diffusive systems mimicking the dynamics of active filament bundles where the filaments are aligned with respect to a common axis. After introducing the model class we first analyze an exactly solvable case and find condensation. For the general case we perform a mean-field analysis and study the behavior on large length scales by coarse-graining. We determine conditions for condensation and establish a relation between the hopping rates and the tension generated in the bundle.