Human immunodeficiency virus type 1 Viral protein R (Vpr) (Vpr)

Human immunodeficiency virus type 1 Viral protein R (Vpr) is a 96-amino acid accessory protein that is essential for viral pathogenesis and efficient replication in vivo (UniProt P03401). It is packaged into the HIV-1 virion and functions early in the viral life cycle by facilitating the nuclear import of the viral pre-integration complex (PIC) into the nucleus of non-dividing cells, such as macrophages (PubMed: 10644350). Vpr is most notably characterized by its ability to induce cell cycle arrest at the G2/M phase, a process that enhances viral transcription by providing an optimal cellular environment for the HIV-1 long terminal repeat (LTR) promoter (PubMed: 15141011). Furthermore, Vpr acts as a molecular adaptor that recruits the CRL4(DCAF1) E3 ubiquitin ligase complex to induce the degradation of various host proteins, including the restriction factor SAMHD1 and the uracil-DNA glycosylase UNG2, thereby promoting immune evasion and viral fitness (PubMed: 24336214). In the context of disease, Vpr contributes to the depletion of CD4+ T cells through the induction of apoptosis and is implicated in HIV-associated neurocognitive disorders (HAND) due to its ability to cross the blood-brain barrier and exert neurotoxic effects on neurons and astrocytes (PubMed: 29431096). Although there are currently no FDA-approved drugs that specifically target Vpr, it remains a high-priority target for therapeutic development. Experimental strategies include the use of small molecules like DAMNI or inhibitory peptides designed to disrupt Vpr's interaction with host proteins or neutralize its cell cycle-modulating effects (PubMed: 22438545). Targeting Vpr could potentially complement existing antiretroviral therapies (ART) by addressing viral persistence and the chronic inflammatory states associated with HIV infection.

Other names

Viral protein RVpr proteinHIV-1 VprR protein

Inhibition of Vpr-mediated G2/M cell cycle arrest, disruption of Vpr-DCAF1 interaction to prevent host protein degradation, and blocking of Vpr-mediated nuclear import of the pre-integration complex (PubMed: 22438545, 24336214).