Human APOBEC3F is another host factor that blocks human immunodeficiency virus type 1 replication.

Recently, APOBEC3G has been identified as a host factor that blocks retroviral replication. It introduces G to A hypermutations in newly synthesized minus strand viral cDNA at the step of reverse transcription in target cells. Here, we identified the human APOBEC3F protein as another host factor that blocks human immunodeficiency virus type 1 (HIV-1) replication. Similar to APOBEC3G, APOBEC3F also induced G to A hypermutations in HIV genomic DNA, and the viral Vif protein counteracted its activity. Thus, APOBEC family members might have evolved as a general defense mechanism of the body against retroviruses, retrotransposons, and other mobile genetic elements.