The dynamics of cargo driven by molecular motors in the context of asymmetric simple exclusion processes

TL;DR

This paper models cargo transport by molecular motors using an ASEP framework, incorporating motor-cargo interactions, and reveals a phase transition affecting cargo velocity.

Contribution

It introduces a novel ASEP-based model that explicitly includes motor-cargo interactions, extending previous models of motor density profiles.

Findings

System exhibits a phase transition of condensation type with changing motor density.

Cargo velocity properties are significantly affected by the phase transition.

Model provides insights into cargo dynamics in biological transport systems.

Abstract

We consider the dynamics of cargo driven by a collection of interacting molecular motors in the context of an asymmetric simple exclusion processes (ASEP). The model is formulated to account for i) excluded volume interactions, ii) the observed asymmetry of the stochastic movement of individual motors and iii) interactions between motors and cargo. Items (i) and (ii) form the basis of ASEP models and have already been considered in the literature to study the behavior of motor density profile [Parmeggiani 03]. Item (iii) is new. It is introduced here as an attempt to describe explicitly the dependence of cargo movement on the dynamics of motors. The steady-state solutions of the model indicate that the system undergoes a phase transition of condensation type as the motor density varies. We study the consequences of this transition to the properties of cargo velocity.