Plays a role in nuclear translocation of the viral pre-integration complex (PIC), thus is required for the virus to infect non-dividing cells. Targets specific host proteins for degradation by the 26S proteasome. Acts by associating with the cellular CUL4A-DDB1 E3 ligase complex through direct interaction with host VPRPB/DCAF-1. This change in the E3 ligase substrate specificity results in the degradation of host SAMHD1. In turn, SAMHD1 depletion allows viral replication in host myeloid cells by preventing SAMHD1-mediated hydrolysis of intracellular dNTPs necessary for reverse transcription (By similarity). Interacts with the P6 region of unprocessed GAG. Interacts with host VPRBP/DCAF1, leading to change substrate specificity of the CUL4A-DDB1 E3 ligase complex (By similarity). Nuclear just after virion uncoating, or if expressed in the absence of unprocessed GAG. This is an African green monkey isolate. Belongs to the lentivirus VPX protein family.