Fig 3.

L4-33K mutant virus gene expression. (A) Northern blot analysis of Ad late gene mRNAs in Ad5-WT- or 33K⁻-infected A549 cells. Total cytoplasmic mRNAs isolated from the infected cells at 12, 24, and 48 hpi were analyzed by Northern blotting using ³²P-labeled probes for each late region. (B) RT-PCR analysis of L4-22K mRNA levels in Ad5-WT- or 33K⁻-infected A549 cells. (C) Western blot analyses of Ad early and late proteins in A549 and TetC4 cells. Representative early (E1A and DBP), intermediate (IVa2), and late (L1 to L5) gene products were analyzed by using whole-cell extracts (WCE) and nuclear extracts (NE) isolated from Ad5-WT- and 33K⁻-infected A549 cells (left) or WCE isolated from Ad5-WT- and 33K⁻-infected TetC4 cells (right) at different times (hours) postinfection (indicated at the top). Protein designations are indicated on the right; tubulin was analyzed as a loading control.