FIGURE 4.
FRAP analysis of TatGGG-driven nuclear import kinetics. A, example FRAP measurement conducted on TatGGG-EGFP. Representative images are depicted. Scale bar, 10 μm. B, excess active fluxes (ΦC→N, mol/s) are calculated cell-by-cell and plotted against the corresponding cytoplasmic cargo concentration, obtaining the whole population data plot for TatGGG-EGFP (red dots) (compared here with NLSSV40-EGFP, green dots). C, plot of calculated Keq against cargo cytoplasmic concentration. D, ΦC→N plot for TatGGG, TatRGG, and TatRRG mutants, showing the decrease in overall affinity (slope of the curve) and the conservation of the maximal import rate allowed (plateau).