Fig. 5. Targeting of PEX26 fragments to nonperoxisomal compartments. (A) Staining of mitochondria (Mc). Transiently transfected human fibroblasts were processed for indirect immunofluorescence using anti-TRAP1 antibodies to visualize mitochondria. The achieved staining pattern was compared with that caused by the GFP fluorescence of the indicated PEX26 fusion proteins. GFP-PEX26_2-274 and also some PEX26_245-305 showed a congruent staining pattern with the mitochondrial marker protein. (B) Staining of the ER. The same kind of transfected cells were labeled with an anti-calreticulin antibody and were similarly analyzed for colocalization with the ER. The GFP-PEX26_275-305 fusion protein revealed some overlap with the ER marker. Bar, 10 µm.