Figure 3
From: Limelight on two HIV/SIV accessory proteins in macrophage infection: Is Vpx overshadowing Vpr?
Vpx recruits the Cul4A-DDB1DCAF1 ubiquitin ligase to counteract a cellular retriction in the early phases of macrophage infection. Vpx is absolutely required for HIV-2 infection of human monocyte-derived macrophages. During the early steps of replication, Vpx, a virion-packaged protein, hijacks the Cul4A-DDB1 ubiquitin ligase by binding to DCAF1. This leads to the inactivation of a macrophage-specific restriction factor, resulting in the completion of reverse transcription and the integration of viral DNA into the host chromosome. In the absence of Vpx, the restriction factor blocks the accumulation of HIV-2 reverse transcripts.