Apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G)

APOBEC3G is a human cytidine deaminase enzyme belonging to the APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like) family, encoded by the APOBEC3G gene. It is best known for its critical role in the innate immune defense against retroviruses, especially HIV-1. APOBEC3G catalyzes the deamination of cytidine to uridine in single-stranded DNA intermediates during reverse transcription of retroviral genomes. This results in G→A hypermutations, which can inactivate viral replication. APOBEC3G is specifically incorporated into nascent virions in an RNA-dependent manner and functions primarily in the cytoplasm of target cells. HIV-1 encodes the Vif protein, which counteracts APOBEC3G by targeting it for polyubiquitination and proteasomal degradation. Beyond its antiviral role, aberrant APOBEC3G activity in host cells can cause off-target DNA editing, contributing to genomic instability and cancer. There are no approved drugs targeting APOBEC3G directly; its main interactions are with viral elements, making it a theoretical but challenging therapeutic target.

Other names

DNA dC->dU-editing enzyme APOBEC-3GMDS019APOBEC-related proteinARCDARP-9CEM15A3GdJ494G10.1FLJ12740bK150C2.7APOBEC-related cytidine deaminaseAPOBEC-related protein 9CEM-15Deoxycytidine deaminaseapolipoprotein B editing enzyme catalytic polypeptide-like 3Gapolipoprotein B mRNA editing enzyme cytidine deaminaseapolipoprotein B mRNA-editing enzyme catalytic polypeptide 3Gphorbolin-like protein MDS019

Cytidine deamination (C→U) of single-stranded DNA, inducing hypermutation and inactivation of viral genomes; Packaging into virions by association with viral RNA and Gag protein; activity antagonized by viral Vif-mediated ubiquitination and proteasomal degradation