Studying Dynein Mechanochemistry with an Optical Trap

Abstract

Molecular motors generate force and mechanical work to perform some of the most energy-demanding cellular processes, such as whole cell motility and cell division. These motors experience resistance from the viscoelastic environment of the surrounding cytoplasm, and opposing forces that can originate from other motors bound to cytoskeleton. Optical trapping is the most widely used method to measure the force-generating and force-response characteristics of motor proteins. Here we present the methodologies of three different optical trapping assays we use to measure how forces originating from external factors affect the microtubule-detachment rate and velocity of dynein. We also briefly discuss the remaining challenges and future directions of optical trapping studies of dyneins and other microtubule-based motors.