Fig. 5. UV-induced degradation of DDB2. (A) Two DDB2-YFP cells were locally damaged by UV irradiation (nuclei indicated by the green dotted outline), while a third cell was not irradiated (indicated by the red dotted outline). The same three cells are shown shortly after (40 seconds) and 6 hours after UV irradiation. (B) Example of a DDB2-EYFP cell that has been globally UV irradiated (16 J/m²) and monitored for 5 hours. (C) Example of a globally UV irradiated (16 J/m²) DDB2-EYFP cell that had been treated with 50 µM MG-132. (D) Quantification of the total nuclear fluorescence in the absence of UV-C irradiation (green line, NoDa, n=8) and after global UV irradiation (GloDa) of MRC5 human cells with 4 (light-purple line, n=10), 8 (red line, n=12) and 16 J/m² (light-blue line, n=10), and in XP-C (dark-blue line, n=15) and XP-A (dark-purple line, n=7) cells with 16 J/m². All values were corrected for background fluorescence and the initial total nuclear fluorescence intensity was set to 100%. The error bars represent the standard error of the mean.