Fig. 6. FRAP analysis of DDB2 mobility in UV-irradiated cells. (A) Example of a globally UV-irradiated DDB2-EYFP cell in which a narrow strip (2 µm) across the nucleus was bleached. (B) Recovery kinetics of DDB2-EYFP in undamaged cells (red line, NoDa, n=14), in locally damaged cells (green line, outside LoDa, n=14) and in globally UV-irradiated cells (4 J/m²; blue line, GloDa, n=15). The recovery plots are normalized to 0 and to the pre-bleach intensity. (C) The recovery plots of DDB2-EYFP in globally damaged cells 1 hour after (purple line, GloDa, n=16) and 4 hours after (blue line, GloDa, n=15) irradiation with 16 J/m². The recovery plots of mutant R273H DDB2 (red line, n=12) and EYFP-histone H2A (green line, n=15) 1 hour after irradiation (16 J/m²) are also shown. The recovery plots are normalized to 0 and to the pre-bleach intensity. (D) Normalized recovery of DDB2-EYFP in cells irradiated with 4 J/m² (blue line, GloDa). The recovery plot is normalized to post-bleach intensity and compared to DDB2-EYFP in undamaged cells (red line, NoDa). (E) UV-immobilized fraction of DDB2-EYFP in MRC5 cells 1 hour after global irradiation with 4, 8 and 16 J/m² and 4 hours after 16 J/m². The immobilized fractions depicted in E were determined by Monte Carlo simulations. The bound fractions obtained from the ten best simulations that fitted the experimental data were averaged. The error bars represent the standard deviation.