DNA dC->dU-editing enzyme APOBEC-3G (APOBEC-related cytidine deaminase, ARCD, APOBEC-related protein, apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3g, phorbolin-like protein MDS019, dj494g10.1, FLJ12740, ARP-9, CEM15, CEM-15, APOBEC3G)

^[1]^[2]

Function

DNA deaminase (cytidine deaminase)
mediates a form of innate resistance to retroviral infections (at least to HIV-1infection) by triggering G-to-A hypermutation in the newly synthesized viral DNA
- replacements C-to-U in the minus strand DNA of HIV-1 during reverse transcription, leads to G-to-A transitions in the plus strand
- inhibition of viral replication is either due to degradation of minus strand before its integration or to lethality of the hypermutations
- modification of both DNA strands is not excluded
antiviral activity is neutralized by the virion infectivity factor (VIF), that prevents the incorporation of APOBEC3G into progeny HIV-1 virions by both inhibiting its translation &/or by inducing its ubiquitination & subsequent degradation by the 26S proteasome
APOBEC3G binds a variety of RNAs, but does not display detectable APOB, NF1 & NAT1 mRNA editing
interacts with APOBEC3B, APOBEC3F & HIV-1 VIF (species specific)
ubiquitinated in the presence of HIV-1 VIF
inhibits also infectivity of retroviral particles only distantly related to HIV-1, such as the simian immunodeficiency virus (SIV), the equine infectious anemia virus (EIAV) & the murine leukemia virus (MLV)

expressed in spleen, testes, ovary, peripheral blood leukocytes & CD4+ lymphocytes
also expressed in non-permissive peripheral blood mononuclear cells, & several tumor cell lines
no expression detected in permissive lymphoid & non-lymphoid cell lines

1 of 7 related genes or pseudogenes found in a cluster, thought to result from gene duplication, on chromosome 22