FIGURE 3.

Vpr mediates MUS81-EME1 down-regulation via the ubiquitin/proteasome pathway. A, MUS81 and EME1 plasmids were co-transfected with empty vector plasmid or Vpr plasmid. At 42 h post-transfection, DMSO or MG132 (10 μm final concentration) in DMSO were added to the cell culture. Six hours later, cells were harvested and analyzed by Western blotting. B, MUS81 and EME1 plasmids were co-transfected with empty vector or Vpr and/or ubiquitin plasmid as indicated. Cells were treated with MG132 (10 μm final concentration) at 42 h post-transfection for 6 h. C, cell lysates from B were subjected to co-immunoprecipitation (IP) with anti-FLAG antibody, and elution fractions from co-immunoprecipitation with FLAG peptides were analyzed by Western blotting. All experiments were repeated three times with similar results.