Fig. 5. DDB2 stimulates OGG1 recruitment to densely clustered 8-oxoG sites.

a Representative time-lapse pictures of OGG1-GFP and GFP-DDB2 accumulation at micro-irradiated (405 nm laser) sub-nuclear area, indicated by arrows, in the presence of 50 μM Ro 19-8022 photosensitizer. b Quantification of accumulation kinetics of OGG1-GFP and GFP-DDB2 (as shown in a). c Schematic overview of the molecular interactions of DDB2 within the CUL4A-DDB1-RBX1 E3 ubiquitin ligase complex (CRL), which is required for the successive molecular interactions by ubiquitylation and subsequent DNA repair. The activation of CRL is mediated by covalent attachment of the ubiquitin-like activator NEDD8 on CUL4A and its proteolytic removal leads to the deactivation of ubiquitin ligase function. These crucial events can be fine-tuned by specific inhibitors MLN4924 (NAE1i) and SB-58-SN29 (CSN5i), acting on NEDD8-activating enzyme NAE1 and CSN5, respectively. d Representative time-lapse pictures of OGG1-GFP accumulation at micro-irradiated (405 nm laser) sub-nuclear area, indicated by arrows, in the presence of 10 μM Ro 19-8022 photosensitizer. Cells were pretreated with DMSO (CTR), NEDDylation inhibitor (NAE1i) or de-NEDDylation inhibitor (CSN5i) for 1.5 h. e Quantification of accumulation kinetics of OGG1-GFP (as shown in d). f Immunoblot analysis for DDB2, CUL4A, CSA and AQR (loading control) in MRC-5 expressing OGG1-GFP. Cells were treated with inhibitors as indicated in d. Scale bars: 5 µm. Data were normalized to the background and represent mean ± SEM from three independent experiments. Total number of cells “n” measured are indicated in figure legends. ****P  <  0.001, analyzed by ROC curve analysis. Source data are provided as a Source Data file. (See also Supplementary Fig. 6).