Two Highly Variable Vpr84and Vpr85 Residues within the HIV-1-Vpr C-Terminal Protein Transduction Domain Control Transductionnal Activity and Define a Clade Specific Polymorphism

The virally encoded HIV-1 viral protein R (VPR) is a multifunctional factor that is required for induced HIV-1 pathogenesis. VPR is also a cell-penetrating protein found in biological fluids from HIV-1 infected individuals. In this regard, we previously published that the C-terminal VPR77-92 sequence from HIV-1 89.6, but not from pNL4.3 strain, is a new pro-apoptotic and protein transduction domain (PTD). Here we report on a sequence analysis of VPR77-92 domain using the Los Alamos HIV-1 sequence database. The analysis showed that the two residues of the domain VPR84 and VPR85 are highly variable and differently biased in HIV-1 clade B and HIV-1 clade C. Furthermore, when Jurkat lymphoblastoid cells or PBMC were incubated with chemically synthesized peptides containing distinct VPR77-92 C-terminal sequences from clades B or C, we found that a clade-dependent polymorphism in VPR84 and VPR85 residues controlled the transducing activity of the C-terminal HIV-1 VPR77-92 domain. Together our data indicate that clade-dependent polymorphism in the VPR84 and VPR85 residues defines the transducing properties mediated by the C-terminal domain of HIV-1 VPR. Identification of this VPR polymorphism suggests new approaches to understand the HIV-1 biology and/or pathogenesis.