Apolipoprotein B mRNA editing enzyme catalytic subunit 3A (APOBEC3A)

Apolipoprotein B mRNA editing enzyme catalytic subunit 3A (APOBEC3A) is a member of the APOBEC protein family, which consists of DNA cytidine deaminases involved in innate immunity through the restriction of retroviruses, DNA viruses, and mobile genetic elements[1][4]. APOBEC3A specifically catalyzes cytidine to uracil conversion in single-stranded DNA (ssDNA), thereby introducing mutations that can degrade foreign DNA or inhibit its integration and propagation[1][4]. APOBEC3A displays the highest catalytic activity within its family and can induce extensive C>U deamination, especially when acting on ssDNA rich in deoxythymidine nucleotides adjacent to target cytidine residues[1]. While this activity confers antiviral and antiretroelement restriction, deregulated APOBEC3A expression can lead to somatic mutations, DNA breaks, and activation of the DNA damage response in host cells[2][3][4]. This mutagenic activity is implicated in various human cancers, where APOBEC mutational signatures are prevalent[4]. The protein also plays a role in epigenetic regulation and potentially active DNA demethylation[3]. Safety concerns include potential genomic instability and off-target effects leading to carcinogenesis in proliferating cells[2][4]. No direct pharmacological inhibitors or interacting drugs targeting APOBEC3A are currently in clinical use, but its activity is increasingly recognized as therapeutically relevant in oncology and virology.

Other names

DNA dC->dU-editing enzyme APOBEC-3AA3AARP3PHRBNPhorbolin-1phorbolin Iapolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3Aprobable DNA dC->dU-editing enzyme APOBEC-3AbK150C2.1

Cytidine deamination (conversion of cytosine to uracil in single-stranded DNA, resulting in mutations in viral and cellular genomes); Induction of DNA damage and cell cycle arrest via DNA strand breaks