Particle interactions and lattice dynamics: scenarios for efficient bidirectional stochastic transport?

Abstract

Intracellular transport processes driven by molecular motors can be described\nby stochastic lattice models of self-driven particles. Here we focus on\nbidirectional transport models excluding the exchange of particles on the same\ntrack. We explore the possibility to have efficient transport in these systems.\nOne possibility would be to have appropriate interactions between the various\nmotors' species, so as to form lanes. However, we show that the lane formation\nmechanism based on modified attachment/detachment rates as it was proposed\npreviously is not necessarily connected to an efficient transport state and is\nsuppressed when the diffusivity of unbound particles is finite. We propose\nanother interaction mechanism based on obstacle avoidance that allows to have\nlane formation for limited diffusion. Besides, we had shown in a separate paper\nthat the dynamics of the lattice itself could be a key ingredient for the\nefficiency of bidirectional transport. Here we show that lattice dynamics and\ninteractions can both contribute in a cooperative way to the efficiency of\ntransport. In particular, lattice dynamics can decrease the interaction\nthreshold beyond which lanes form. Lattice dynamics may also enhance the\ntransport capacity of the system even when lane formation is suppressed.\n