Microtubule (MT)-based motors like kinesin play important cellular roles and are essential for both long-distance transport of cargos (e.g. in axons) and also for cell division. MTs are polar (directed) filaments, and in cells, kinesin moves cargos toward the plus-end of MTs while dynein drives them toward the MT minus end. Defects in motor-based transport are closely linked to neurodegenerative diseases, including Alzheimer's and Huntington's diseases.

Long-distance transport reflects the collective behavior of the motors functioning as a team bound to cargos. Importantly, we lack a full understanding how motors work together, or how their collective function can be regulated to control the motion of vesicles in cells. This lack partly reflects the difficulty in studying the process in cells, where one cannot easily determine or control the motor number or the presence of associated regulatory factors. The recent successful efforts to characterize structures and functions of single molecular motors in vitro are a crucial first step to understanding the more complicated intracellular motion of cargos. The next step that is a focus of my long-term research is to tackle three related problems: how do multiple motors function together, which properties of single-motors are important for this function, and how are these properties regulated?