Fig. 7

The autophagy receptor, OPTN, is also retained at Parkin-positive mitochondria after repolarization. a-f HeLa cells expressing mCherry-Parkin and OPTN-EGFP were imaged by live cell microscopy and were either (a-d) pulsed for 60 min or (e + f) treated continuously with 10 μM CCCP. Timecourse images for cells pulsed for 60 min are depicted in (a), together with corresponding zoomed images and line scan pixel intensity measurements of mCherry-Parkin and OPTN-EGFP fluorescence taken at (b) 60 min and (c) 120 min. Thin white lines mark the trajectory of the line scan measurement in (b + c). OPTN-EGFP (green) puncta are found to be associated with mitochondrial fragments coated with mCherry-Parkin (red) within 60 min after initial CCCP exposure and these remain associated for at least 60 min post-CCCP washout. d For the cell depicted in (a-c), colocalization between mCherry-Parkin and OPTN-EGFP within a ~ 10 × 10 μm region of the cytosol was assed overtime by PCC. e Image of cells at 120 min after continuous treatment with CCCP together with (f) corresponding zoomed images and line scan pixel intensity measurements of mCherry-Parkin and OPTN-EGFP fluorescence. At this timepoint crescents or rings of OPTN surround EYFP-Parkin-coated mitochondrial fragments