(b) MEFs stably expressing FLAG-Parkin and EGFP-tagged forms of FKBP38, Omp25, Omp25/FKBP38 or FKBP38/Omp25 were treated with CCCP (30 μM) for 4 h, fixed, permeabilized and subjected to immunofluorescence analysis with antibodies to cytochrome c and to FLAG (rabbit polyclonal). The fluorescence of EGFP was also monitored directly. Scale bar, 10 μm. 