The role of RNA in the packaging APOBEC3G into human immunodeficiency virus type 1 particles

Abstract

APOBEC3G is a cytidine deaminase that inhibits HIV replication at a post-entry step in replication. APOBEC3G must be incorporated into the virus particle during assembly in order to inhibit HIV during the next round of replication. We defined the highly basic region between the two zinc binding domains in the nucleocapsid subunit of the viral Gag protein as a crucial packaging domain for APOBEC3G. Using a novel fluorescent resonance energy transfer (FRET) assay to detect APOBEC multimers, we found that APOBEC3G is packaged as a multimer bound to packaged RNA. We demonstrate for the first time that APOBEC multimers complexed with RNA are specifically recruited to the plasma membrane site of assembly by Gag.