Fig. 7. Dissociation kinetics of DDB2. (A) Example of a DDB2-EYFP cell after local UV irradiation with 100 J/m². A strip of about one third of the cell nucleus opposite the local damage was continuously bleached and the fluorescence decrease in the local damage was monitored. (B) Quantification of the decrease in fluorescence signal in the damaged area of the nucleus. The half-time (t_1/2) of a FLIP curve corresponds to the residence time of a protein molecule in the locally damaged area. FLIP was performed on DDB2-EYFP in MRC5 human fibroblasts at 37°C (purple line, n=10) and at 27°C (orange line, n=10), DDB2-EYFP in XP20MA human XP-C fibroblasts (blue line, n=11), XPF-EGFP in UV135 Chinese hamster ovary XP-G cells (green line, n=8) and XPC-EGFP in XP4PA human XP-C fibroblasts (red line, n=9). The error bars represent the standard error of the mean.