Double-stranded RNA-specific editase B2 (ADARB2)

Double-stranded RNA-specific editase B2 (ADARB2), also known as ADAR3 or RED2, is a member of the double-stranded RNA adenosine deaminase (ADAR) enzyme family, which are known for catalyzing adenosine-to-inosine (A-to-I) editing in RNA substrates. However, unlike active ADAR family members, ADARB2 has no detectable catalytic (deaminase) activity and cannot perform A-to-I editing itself. Instead, it binds both double-stranded and single-stranded RNA, and it is thought to play a regulatory role, inhibiting RNA editing by competing with active ADAR enzymes (such as ADAR1 or ADARB1) for substrate binding. Its activity is modulated by interactions with RNA secondary structure elements, and its expression can be regulated by long noncoding RNA and paraspeckle proteins within the nucleus. ADARB2 is mostly brain-enriched, but its exact physiological and pathological roles remain under investigation. There is currently no evidence of small-molecule drugs directly targeting ADARB2, and its lack of intrinsic catalytic activity means it is not presently considered a direct therapeutic target. The gene is associated with regulatory and modulatory functions in RNA editing, particularly impacting neurological processes. Key notes: - ADARB2 is sometimes called ADAR3 in human gene nomenclature, but this can be confusing because ADAR3 is often regarded as a separate gene in some species. - Although not catalytically active, ADARB2 has an indirect role in post-transcriptional gene regulation via RNA editing modulation. - Its best-studied modulation is competitive inhibition—binding RNA substrates and reducing editing efficiency by active ADARs. - Mutations or dysregulation of ADARB2 are linked to altered neurotransmission and have been reported in some cancers and neurodevelopmental disorders, but causality is not fully established.

Other names

Double-stranded RNA-specific editase B2ADARB2ADAR3RED2hRED2RNA-dependent adenosine deaminase 3RNA-editing deaminase 2RNA-editing enzyme 2dsRNA adenosine deaminase B2RED2 homolog (rat)RNA-editing deaminase 2, adenosine deaminase, RNA-specific, B2 (RED2 homolog rat)adenosine deaminase, RNA-specific, B2 (non-functional)dsRNA adenosine deaminase B2, homolog of rat BLUE