Fluctuation effects in bidirectional cargo transport

TL;DR

This paper presents a theoretical model of bidirectional cargo transport in cells driven by molecular motors, capturing anomalous diffusion behaviors and efficiency improvements in crowded environments through extensive simulations.

Contribution

The study introduces a detailed motor-filament interaction model with thermal fluctuations, revealing mechanisms behind anomalous diffusion and transport efficiency in crowded cellular conditions.

Findings

Model reproduces subdiffusive and superdiffusive regimes observed experimentally.

Thermal fluctuations induce subdiffusive behavior at short times.

Correlations among motors generate superdiffusive motion.

Abstract

We discuss a theoretical model for bidirectional cargo transport in biological cells, which is driven by teams of molecular motors and subject to thermal fluctuations. The model describes explicitly the directed motion of the molecular motors on the filament. The motor-cargo coupling is implemented via linear springs. By means of extensive Monte Carlo simulations we show that the model describes the experimentally observed regimes of anomalous diffusion, i.e. subdiffusive behavior at short times followed by superdiffusion at intermediate times. The model results indicate that subdiffuse regime is induced by thermal fluctuations while the superdiffusive motion is generated by correlations of the motors' activity. We also tested the efficiency of bidirectional cargo transport in crowded areas by measuring its ability to pass barriers with increased viscosity. Our results show a remarkable gain of efficiency for high viscosities.