FIG 6 .

DNAJ proteins and BiP are required for ER exit. (A) HeLa/E6 cells expressing the indicated DNAJ shRNA were infected with SV40 at an MOI of 30 for 14 hours. Digitonin lysates were fractionated by centrifugation, and VP1 was detected by immunoblotting in the cytoplasmic and pellet fractions under nonreducing and reducing conditions, respectively. At the time of infection, cells were treated with thapsigargin (lanes 2 and 9) or brefeldin A, (lanes 3 and 10). A shorter exposure of the pellet VP1 blot is shown to allow comparison with the supernatant samples. L, cells expressing Lib1 control shRNA. (B) CV1 cells were infected with SV40 at an MOI of 30 for 14 hours in the presence of 2 ng/ml mutant (M) or active (A) subtilase cytotoxin or in the absence of toxin. The cells were analyzed as described in the legend to panel A.