Fig. 8. Nuclear export rates of GFP-tagged APC constructs measured by FLIP. Individual COS cells transfected with GFP-tagged HC constructs (as indicated) were selected, and their entire cytoplasm was subjected to repetitive photobleaching while their nuclear fluorescence was measured; graphs and images shown are of a representative cell from each group. (A, B, D and E) Confocal sections through transfected cells at various time points as indicated (pre, pre-bleaching). (C and F) Graphic representations of loss of nuclear fluorescence at each time point. Wild-type HC constructs (HC and NLS-HC) show significantly more loss of nuclear fluorescence than NES mutant constructs (HC-ala and NLS-HCala), demonstrating that their nuclear export activity depends on their NESs.