Figure 2. DDB2 interacts with NER proteins. HeLa cells co-transfected with pcDNA3.1-DDB2 and p21-GFP plasmids were grown for 24 h and collected before or 5, 10, and 30 min after UVC irradiation (30 J/m²), as described in “Materials and Methods”. Cells were fractionated in soluble (S) and chromatin-bound (Cb) samples for immunoprecipitation and analysis by western blot. (A) Input load: 1/30 of cell extract. (B) Immunoprecipitation (Ip) with anti-DDB2 antibody on fractionated cell extracts, indicated above. Not transfected cells (sample B) were used as a negative control.