Title: Intermediate Binding States, Motor Length, and Rigidness Affect Intracellular Transport
Abstract: Organelles, vesicles, and other cargoes are transported throughout the eukaryotic cell. One type of transport is by motor proteins in the kinesin and dynein families, traveling along microtubules. It is not clear how the cell transports specific cargoes to specific locations. We hypothesize that the cell tunes the motor length and the spacing between the cargo and MT (via MT-associated proteins) to regulate transport. Using Brownian dynamics simulation and mathematical modeling, we investigate this hypothesis. Our results include the existence of an intermediate state in a motor’s binding to the microtubule, consistent with previous reports of auto-inhibition in kinesin-1, and an unexplored role of effective concentration that is reduced for longer motors.