Fig. 2

Vpr promotes poly-ubiquitination and degradation of SIRT7. a In vitro ubiquitination assays of SIRT7 with CRL4-DCAF1c (DCAF1 residue 1045–1396) or CRL4-DCAF1c-Vpr. Poly-ubiquitinated SIRT7 species are indicated (SIRT7-Ubn). b A constant amount of plasmids expressing SIRT7 were transfected into HEK293T cells with increasing amounts of Vpr-expressing plasmids. Cells were harvested after 48 h, and cell lysate was prepared and subjected to SDS-PAGE and immunoblotting. c Control plasmids or plasmids expressing SIRT7 or Vpr were co-transfected into HEK293T cells. 40 h later, cells were treated with 10 μM MG132. Cells were harvested after an additional 8 h, and cell lysate was prepared for SDS-PAGE and immunoblotting. d Plasmids expressing Vpr were transfected into HEK293T cells. All experiments were repeated two to three times with equivalent results