Human Immunodeficiency Virus type 1 Vif protein

The Human Immunodeficiency Virus type 1 (HIV-1) Vif protein, also known as the Viral Infectivity Factor, is an accessory protein encoded by the *vif* gene in HIV-1 and other lentiviruses. It is essential for viral replication and infectivity, particularly in physiologically relevant cell types such as CD4+ T cells and macrophages. Vif's primary function is to counteract host antiviral defense mechanisms mediated by APOBEC3 family proteins. Vif prevents APOBEC proteins from being packaged into budding virions, which would induce hypermutation of the viral genome during reverse transcription. Vif binds to these APOBEC proteins and recruits a cellular E3 ubiquitin ligase complex, leading to polyubiquitination and subsequent proteasomal degradation of APOBECs. In addition to its role against restriction factors, Vif binds directly to HIV-1 genomic RNA within infected cells and forms part of messenger ribonucleoprotein complexes that may protect viral RNA or mediate its engagement with Gag precursors during assembly. Mutations or deletions that disrupt functional Vif result in drastically reduced infectivity. Vif represents an attractive drug target, and small-molecule inhibitors have been identified that block its interaction with Elongin C or protect various APOBECs from degradation.

Other names

HIV-1 Vif proteinViral Infectivity FactorVif

Inhibition of Vif-Elongin C interaction; Protection of APOBECs from degradation