Effect of confinement and cargo mechanical properties on motor-driven cargo transport

Intracellular transport of cargo by molecular motors is essential for cells to function properly. Cargoes, such as vesicles and organelles, are transported by molecular motors to their correct locations via a combination of active motion on microtubule filaments and passive Brownian motion. During this process, the motor-cargo complex has to navigate the crowded and confining environment of the surrounding biopolymer networks. Additionally, cargos are rarely carried by a single motor and motor-motor interactions may occur during collective transport of cargos. However, most existing models of cargo transport have focused on the dilute limit of a single or a few motors transporting cargo along a single immobilized microtubule. Here we mathematically model cargo transport on a microtubule within a confining filament network using numerical simulations and analytical calculations. We study average displacements, mean squared displacements, and average velocities for different cases, such as single/multiple motor(s) transporting cargo, different cargo sizes, and different confinement widths. Our results may help to elucidate the impact of the cytoskeletal network and cargo mechanical properties on intracellular cargo transport.