FIG 1.

Sendai virus-induced apoptosis depends on caspase-9. (A) HEK293 cells were infected with Sendai virus at an MOI of 0.4, 0.8, or 1.2 for 24 h (left) or at an MOI of 1 for 18, 21, or 24 h (right). Cell death was quantified using annexin V/PI double staining on flow cytometry. (B) HEK293 cells were infected with Sendai virus for the indicated times. Cell lysates were resolved by SDS-PAGE and then immunoblotted (IB) with the indicated antibodies. (C) (Left) HEK293 cells were treated with TNF-α (10 ng/ml) and CHX (10 ng/ml) plus Z-VAD-FMK (2 μM) for the indicated times. (Right) HEK293 cells were infected with Sendai virus plus Z-VAD-FMK (2 μM) for the indicated times. Cell lysates were collected for Western blot analysis with the indicated antibodies. (D) (Left) HEK293 cells were treated with TNF-α (10 ng/ml) and CHX (10 ng/ml) plus Z-LEHD-FMK (2 μM) for the indicated times. (Right) HEK293 cells were infected with Sendai virus plus Z-LEHD-FMK (2 μM) for the indicated times. Cell lysates were collected for immunoblot analysis with the indicated antibodies.