Figure 6.
E6-mediated p53 degradation is only partially inhibited by inactivation of E1. (a) TS20b cells were transfected with p53 together with Mdm2 (lanes 5, 6, 11 and 12), E6 (lanes 1, 2, 7 and 8) or pcDNA3 (lanes 3, 4, 9and 10) and left at 35°C (lanes 1-6) or moved to the non-permissive temperature of 39°C (lanes 7-12) 20 h before harvesting. Cells were incubated for 3 h before harvesting with 20 μM MG132 as indicated (lanes 2, 4, 6, 8, 10 and 12). (b) As above but a longer exposure of the 35°C samples (lanes 1-6) and a shorter exposure of the 39°C samples (lanes 7-12). (c) Parental H38-5cells were transfected as in (a) and moved to 39°C 20 h before harvesting. (d) Graph showing degradation of p53 mediated by E6 (dark shaded bars) and Mdm2 (light shaded bars) at the permissive temperature (35°C) and the non-permissive temperature (39°C).