Fig. 1

Time lapse imaging stills of an ARPE-19 cell undergoing apoptosis. The stills shown are of a cell treated with 0.01 µM elamipretide and 1 µM staurosporine. This cell was nucleofected with plasmids expressing mCherry-BAX, cytochrome c-GFP, and mitoBFP fusion proteins. The images just prior to the initiation of BAX recruitment are shown (A, E, I, M), along with +2 min, + 4 min, and + 26 min after this time stamp. Some BAX puncta are evident just prior to the declaration of BAX recruitment (E) and it is not clear if these are activated BAX aggregates, or excess fusion protein that is sequestered in lysosomes [3]. Once BAX recruitment is initiated, cytochrome c moves from a mitochondrial localization (I) to a diffuse cytosolic localization (J–L). Mitochondria remain intact through the initial stages of BAX recruitment (M–O) but become rapidly fragmented and difficult to detect shortly after BAX becomes fully recruited (D, H, L, P). These results are typical for both vehicle and elamipretide treated cells. Images for cytochrome c-GFP have been modified to enhance exposure levels. Size bar = 7 µm