Fig. 5. Both MTS and ATAP are involved in mitochondrial-targeting apoptosis induced by HCCS1. (A) Schematic representation of the GFP fusion proteins of HCCS1 and its deletion mutants. (B) Subcellular localization of GFP fusion proteins. HeLa cells were transfected with 0.5 µg of the indicated plasmids. Cell culture was performed in the presence of 50 µM OPH. 18 hours after transfection, cells were incubated in medium containing 50 nM MitoTracker for 2 hours and fixed using 4% paraformaldehyde. Localization of GFP fusion proteins was observed using confocal microscopy. Bar, 10 µm. (C) Cell survival was measured by PI exclusion in the HEK293 cells transfected with 1 µg GFP fusion constructs 24 hours after transfection.