Parkin-mediated ubiquitination recruits p62 and HDAC6. MEFs were transfected with WT, A240R, and T415N mutant GFP-parkin followed by CCCP treatment for 8 h. Cells were double immunostained with cytochrome c (red) and p62 antibody (blue) in A, and cytochrome c (red) and HDAC6 antibody in C. Arrows indicate mitochondrial aggregates. (B and D) The average percentages of p62- or HDAC6-positive mitochondrial aggregates from three independent experiments are presented with standard deviation as error bar. (E) Wild-type and HDAC6 knockout (KO) MEFs were transfected with parkin-GFP or cotransfected with a Flag-tagged HDAC6 followed by CCCP treatment for 16 h as indicated. Cells are immunostained with Tom20 (red) and Flag (blue) antibodies. Bar, 25 µm. (F) Wild-type MEFs were transfected with control or HDAC6 siRNA and parkin-GFP, and treated with or without CCCP for 16 h. Cell lysates were subjected to immunoblotting analysis using antibodies for Tom20, parkin, HDAC6, and actin.