PHF13 degradation by HIV-1 Vpr mutants and primary HIV-1 Vpr alleles. (a) SupT1 cells were infected with 200 ng p24 of VSVG pseudotyped HIV-1 NL4-3 IRES-eGFP, the ΔVpr variant or variants carrying the indicated amino acid substitutions in Vpr. Forty-eight hours later, cells were lysed and subjected to immunoblot for detection of PHF13, HIV-1 p24, actin and Vpr. (b) SupT1 cells were infected with 200 ng p24 of VSVG pseudotyped HIV-1 NL4-3 or the ΔVpr variant that were transcomplemented in the 293T producer cells with the indicated Vpr mutant, WT Vpr or GFP only as a control. Forty-eight hours later, cells were lysed and subjected to immunoblot for detection of PHF13, HIV-1 p24 and actin. (c) SupT1 cells were infected with 200 ng of bicistronic pWPI-GFP lentiviral reporter constructs co-expressing GFP and the indicated primary HIV-1 Vpr alleles, Vpr from the laboratory-adapted HIV-1 reference strain HXB as a control, or GFP only. Forty-eight hours later, cells were lysed and subjected to immunoblot for detection of PHF13, actin and GFP. The data presented in (a)–(c) were confirmed in at least two additional biological replicates.