Fig. 5.

Knockdown of DDB1 relieves Vpr-induced apoptosis. (A) HeLa cells were transfected with wild-type or L64P Vpr expression vector or empty vector. Apoptosis was detected 3 days later by TUNEL. (B) Cells were fixed and stained with propidium iodide and analyzed by FACS. (C) HeLa cells were transfected with control siRNA or siRNA against DDB1. Three days posttransfection, the cells were fixed and stained with propidium iodide. The cell-cycle profiles were analyzed by FACS. (D) HeLa cells were transfected with control siRNA or DDB1-specific siRNA and, 24 h later, with wild-type Vpr. Three days later, apoptosis was measured by TUNEL.