FIG. 5.

(A) Effect of E1A protein isoforms on BIK and BIM expression. A549 cells were infected with wt Ad5 or the indicated mutants, and expression of BIK and BIM was determined by Western blot analysis. (B) ChIP analysis of transcription factors associated with the Bik promoter. The results of ChIP analysis of E2F1 and p53 are shown. Immunoprecipitation with the antibody specific to RNA polymerase II (Pol II) and the PCR primers specific to the GAPDH promoter (Upstate) were used in the control ChIP assays. IgG, immunoglobulin G. (C) CR2-independent activation of BIK. BIK expression in A549 cells infected with the indicated Ad mutants was determined by Western blot analysis. (D) Roles of E1A protein isoforms on induction of apoptosis. A549 cells infected with the indicated viruses were maintained under 20 μg/ml of cytosine arabinoside for 36 h, and the low-MW intracellular DNA was analyzed as described in the legend to Fig. 2.