FIG. 4.

pUL38 expression alone blocked cell death induced by the stress on the endoplasmic reticulum. (A) HFs transduced with empty retroviral vector (HF-vector) or with pUL38-expressing retroviral vector (HF-UL38) were treated with tunicamycin at the indicated concentrations, and cell survival was measured by ATP viability assay at 48 h posttreatment. (B) HF-vector or HF-UL38 cells were treated with 2 μg of tunicamycin/ml, and cell survival was measured at different times posttreatment as indicated. Cell viability was normalized to that of untreated cells.