Membrane-bound cargo carried by teams of motors with heterogeneous velocities go faster and further than rigid cargo

Abstract

Intracellular transport by teams of molecular motors is an essential cell-biological process that ensures the proper distribution of organelles, and other materials within cells. These teams of motors cooperate and compete in complex ways to achieve desired transport velocity and runlength. In-vitro experiments have observed that coupling motors through a lipid membrane that mimics in vivo membrane-bound cargoes leads to a higher cargo velocity. However, the mechanisms behind this increase in lipid cargo velocity are unclear. Here we seek to understand these mechanisms using Brownian dynamics simulations. We show that an underlying heterogeneity in single motor velocity is essential for the increased velocity of lipid cargoes. Our simulations also show that while the runlengths of both rigid and lipid cargoes increase, and the velocities decrease, with an increase in the fraction of slower motors, lipid cargoes can travel faster and substantially further with the same degree of heterogeneity, suggesting functional advantages of motor velocity heterogeneity. Together, our work explains mechanisms behind previous experimental observations and generates new experimentally testable predictions on velocities and runlengths relevant for in vivo transport.