question: What is the mechanism by which HIV-1-encoded Vif protein allows virus replication?
answer: The HIV-1 Vif protein counteracts the antiviral activity of the APOBEC3 family by targeting the proteins for degradation through the ubiquitin-proteasome pathway. More specifically, Vif, serving as a substrate receptor, facilitates ubiquitination of APOBEC3 proteins by forming a Cullin5-based E3 ubiquitin ligase complex, which targets APOBEC3 proteins for rapid proteasomal degradation.