Mechanisms of vesicle trafficking and kinesin regulation - PROJECT SUMMARY Nearly every aspect of cellular function—from development to metabolism and signaling—requires that membrane proteins be targeted to the correct location in the cell. This process requires high specificity as different cargoes are destined for different destinations. Although the basic steps of this process are known (i.e., cargoes are sorted into vesicles, the proper kinesins are recruited, and kinesins then transport vesicles to the proper destination), our current understanding of the mechanisms by which kinesins are recruited to vesicles and how their action is regulated on vesicles in live cells is extremely limited. Previously, the field lacked many of the tools needed to better characterize and understand these mechanisms, but our group has developed several cutting-edge tools that allow us for the first time to answer several fundamentally important questions. In this project, we will apply our experience with these tools in combination with primary hippocampal neuron culture and live cell imaging to achieve four key goals: 1) determine the mechanisms of on-vesicle regulation for kinesin- mediated transport, using Kinesin-3 family member KIF13A as an initial model, 2) identify molecular links between cargo sorting and kinesin recruitment, 3) determine the mechanisms that underlie the sorting of polarized cargoes at the trans-Golgi network, and 4) develop additional molecular tools in pursuit of these goals that also have applicability to the broader trafficking community.