ADAR Gene

The ADAR gene (ADAR stands for "Adenosine Deaminase RNA Specific") is a protein coding gene located on chromosome 1q21.3. The ADAR gene encodes a deaminase responsible for RNA editing by site-specific deamination of adenosines. This enzyme destabilizes double-stranded RNA by converting adenosine to inosine.

The "Adenosine Deaminase RNA Specific" catalyzes the hydrolytic deamination of adenosine to inosine in double-stranded RNA (dsRNA), which is referred to as A-to-I RNA editing. This can affect gene expression and function in several ways (Nishikura K 2010).

The protein enzyme can edit both viral and cellular RNAs and can edit RNAs at multiple sites (hyper-editing) or at specific sites (site-specific editing).

Its cellular RNA substrates include:

• the bladder cancer-associated protein (BLCAP),
• the neurotransmitter receptors for glutamate (GRIA2) and serotonin (HTR2C)
• the GABA receptor (GABRA3).

Site-specific RNA editing of transcripts encoding these proteins results in amino acid substitutions, altering their functional activities.

Diseases associated with the ADAR gene include.

• Dyschromatosis symmetrica hereditaria
• and
• Aicardi-Goutières syndrome 6 (OMIM: 615010).

1. Nishikura K (2010) Functions and regulation of RNA editing by ADAR deaminases. Annu Rev Biochem 79:321-349.
2. Qu L et al (2019) Programmable RNA editing by recruiting endogenous ADAR using engineered RNAs. Nat Biotechnol 37:1059-1069.
3. Zhao Z et al. (2019) Analysis of ADAR gene mutations in two pedigrees affected with dyschromatosis symmetrica hereditaria. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 36: 574-576.