APOBEC3G

This gene is a member of the cytidine deaminase gene family. It is one of seven related genes or pseudogenes found in a cluster, thought to result from gene duplication, on chromosome 22. Members of the cluster encode proteins that are structurally and functionally related to the C to U RNA-editing cytidine deaminase APOBEC1. The protein encoded by this gene catalyzes site-specific deamination of both RNA and single-stranded DNA. The encoded protein has been found to be a specific inhibitor of human immunodeficiency virus-1 (HIV-1) infectivity. [provided by RefSeq, Mar 2017]

Full Name

Apolipoprotein B MRNA Editing Enzyme Catalytic Subunit 3G

Function

DNA deaminase (cytidine deaminase) which acts as an inhibitor of retrovirus replication and retrotransposon mobility via deaminase-dependent and -independent mechanisms. Exhibits potent antiviral activity against Vif-deficient HIV-1. After the penetration of retroviral nucleocapsids into target cells of infection and the initiation of reverse transcription, it can induce the conversion of cytosine to uracil in the minus-sense single-strand viral DNA, leading to G-to-A hypermutations in the subsequent plus-strand viral DNA. The resultant detrimental levels of mutations in the proviral genome, along with a deamination-independent mechanism that works prior to the proviral integration, together exert efficient antiretroviral effects in infected target cells. Selectively targets single-stranded DNA and does not deaminate double-stranded DNA or single- or double-stranded RNA. Exhibits antiviral activity also against simian immunodeficiency viruses (SIVs), hepatitis B virus (HBV), equine infectious anemia virus (EIAV), xenotropic MuLV-related virus (XMRV) and simian foamy virus (SFV). May inhibit the mobility of LTR and non-LTR retrotransposons.

Biological Process

Base conversion or substitution editing Source: HGNC-UCL
Cytidine deamination Source: UniProtKB
Cytidine to uridine editing Source: GO_Central
Defense response to virus Source: UniProtKB
DNA cytosine deamination Source: UniProtKB
DNA demethylation Source: GO_Central
Innate immune response Source: HGNC-UCL
Negative regulation of single stranded viral RNA replication via double stranded DNA intermediate Source: UniProtKB
Negative regulation of transposition Source: UniProtKB
Negative regulation of viral genome replication Source: UniProtKB
Negative regulation of viral process Source: HGNC-UCL
Positive regulation of defense response to virus by host Source: HGNC-UCL
Viral process Source: UniProtKB-KW

Cellular Location

Nucleus; Cytoplasm; P-body. Mainly cytoplasmic. Small amount are found in the nucleus. During HIV-1 infection, virion-encapsidated in absence of HIV-1 Vif.

PTM

Ubiquitinated in the presence of HIV-1 Vif. Association with Vif targets the protein for proteolysis by the ubiquitin-dependent proteasome pathway.
Phosphorylation at Thr-32 reduces its binding to HIV-1 Vif and subsequent ubiquitination and degradation thus promoting its antiviral activity.