Time series representing the assembly of four Nups. The contrast of the image series was normalized to a common maximal mean intensity reached on the nuclear rim at the last time point of each series. Plots on the right show the data obtained from the series shown (green) and the mean of n series (black). As a reference, Nup133 (red) and IBB (dark red) intensity means are shown in all plots. Time stamps give min:s relative to t_1/2(import). Video 1 shows representative full-image sequences for Nup133. Error bars indicate SD.