Fig. 8.

SCCA1 promotes caspase-8 aggregation and activation at lysosomes. Parental and SCCA1-expressing bax^−/− bak^−/− BMK cells were left untreated or treated with tunicamycin (Tuni) for 16 h. Immunofluorescence staining was performed using LysoTracker Red and an antibody against caspase-8 (green). The substrate specific for activated caspase-8, FITC-IETD-FMK, was used to verify that the caspase-8 colocalizing with lysosomes was indeed active (B).