APOBEC3H
Function
DNA deaminase (cytidine deaminase) which acts as an inhibitor of retrovirus replication and retrotransposon mobility via deaminase-dependent and -independent mechanisms (PubMed:16571802, PubMed:16920826, PubMed:18779051, PubMed:18827027, PubMed:20062055, PubMed:22915799, PubMed:29290613). The A3H-var/haplotype 2 exhibits antiviral activity against vif-deficient HIV-1 (PubMed:18299330, PubMed:21835787, PubMed:23097438, PubMed:29290613). 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 (PubMed:18299330). 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 (PubMed:18299330). Selectively targets single-stranded DNA and does not deaminate double-stranded DNA or single- or double-stranded RNA (PubMed:20062055). Exhibits antiviral activity also against T-cell leukemia virus type 1 (HTLV-1) and may inhibit the mobility of LTR and non-LTR retrotransposons (PubMed:20062055, PubMed:22457529).
Post-translational modifications
(Microbial infection) Following infection by some HIV-1 strains, such as isolate BRU/LAI, can be ubiquitinated by a cullin-5-RING E3 ubiquitin-protein ligase complex (ECS complex) hijacked by the HIV-1 Vif protein, leading to its degradation (PubMed:37640699). Ubiquitination by the ECS complex is however less efficent compared to APOBEC3G or APOBEC3G (PubMed:37640699).
Sequence Similarities
Belongs to the cytidine and deoxycytidylate deaminase family.
Tissue Specificity
Expressed in lymphoid organs. Also detected in non-lymphoid tissues including lung, testis, ovary, fetal liver and skin.
Cellular localization
- Cytoplasm
- Nucleus
- Cytoplasm
- P-body
- Haplotype 1 is distributed in both the nucleus and cytoplasm, whereas haplotype 2 is predominantly cytoplasmic.
Alternative names
DNA dC->dU-editing enzyme APOBEC-3H, APOBEC-related protein 10, Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3H, ARP-10, A3H, APOBEC3H