Figure 3
From: hSSB2 (NABP1) is required for the recruitment of RPA during the cellular response to DNA UV damage
hSSB2 depletion delays XPC recruitment, impairs RPA recruitment to UV damage sites and increases sensitivity to UVB exposure. (a) Representative images of HeLa cells probed for CPD (green, left panels) and RPA32 (red, middle panels) without UV exposure or 1 h and 3 h after UVC irradiation with a 5 µm filter. Cells were irradiated 48 h after negative control (si Control) and hSSB2 (si hSSB2) siRNAs transfection with UVC covered with 5 µm filter. DNA is stained with DAPI (blue, right panels). Average RPA32 fluorescent staining intensity at the CPD sites (± sem, n = 3) has been reported in graph (b). (c) Representative images of HeLa cells probed for CPD (green, left panels) and XPC (red, middle panels) without UV exposure or 15 min and 1 h after UVC irradiation. DNA is stained with DAPI (blue, right panels). Average XPC fluorescent staining intensity at the CPD sites (± sem) has been reported in graph (d). Scale bar represents 5 µm. (e,f) Measure of the average live cells (± sem, n = 3) 48 h after UVB exposure of HeLa cells transfected with negative control (si Control) or hSSB2 (si hSSB2) siRNAs (e) and U-2OS cells (f). Analysis was carried out with the Cytell imaging system 20 min after Hoechst and Propidium Iodide staining (****P-value < 0.0001 in a Student test).
