Fluctuation effects in bidirectional cargo transport
1 Laboratory of Theoretical Physics, CNRS (UMR 8627), University Paris-Sud, Bâtiment 210, 91405 Orsay Cedex, France
2 Fachrichtung Theoretische Physik, Universität des Saarlandes, 66123 Saarbrücken, Germany
Received: 17 October 2014
Revised: 5 November 2014
Published online: 15 December 2014
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 the subdiffusive 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.
© EDP Sciences, Springer-Verlag, 2014