FIG. 4.

Southern blot analysis of the BPV-1 origin plasmid pUCAlu in SAOS-2 cells (radiolabeled origin plasmid pUCAlu used as a probe). p53 mutant proteins inhibit replication of the BPV-1 minimal origin in SAOS-2 cells lacking endogenous p53 and pRB proteins. BPV-1 minimal origin plasmid pUCAlu (500 ng) together with BPV-1 E1 and E2 expression plasmids pCGEag and pCGE2 (1 μg of each) was transfected into the cells; 500 ng of p53 mutant proteins was cotransfected as indicated (lanes 2 to 6). Other lanes: M, 200 pg of the pUCAlu marker linearized with PstI; carrier, control transfection with carrier DNA only; 1, positive control with no p53 construct added.