My laboratory is studying the cell biology of constituents of the nuclear transport machinery. These proteins, which comprise nuclear pore complex proteins and their interacting transport factors, mediate the transport of molecules into and out of the nucleus. We focus on two areas, namely the role of these proteins in nuclear transport under both physiological and pathological conditions, and the role of these proteins during mitosis. Physiologic studies focus on the mechanisms of nuclear import and export, and pathological studies focus on how these processes are disrupted during viral infections. During mitosis, following nuclear envelope breakdown, these constituents of the nuclear transport machinery acquire new functions, and we are studying their roles as regulators of cell cycle progression.