Spatial Distribution and Mobility of the Ran GTPase in Live Interphase Cells

The GTPase Ran is a key regulator of molecular transport through nuclear pore complex (NPC) channels. To analyze the role of Ran in its nuclear transport function, we used several quantitative fluorescence techniques to follow the distribution and dynamics of an enhanced yellow fluorescent protein (EYFP)-Ran in HeLa cells. The diffusion coefficient of the majority of EYFP-Ran molecules throughout the cells corresponded to an unbound state, …