Alternative titles; symbols
HGNC Approved Gene Symbol: ADARB2
Cytogenetic location: 10p15.3 Genomic coordinates (GRCh38) : 10:1,177,313-1,737,525 (from NCBI)
RNA-editing deaminase-2 (RED2, or ADARB2) is a member of the double-stranded RNA (dsRNA) adenosine deaminase family of RNA-editing enzymes. Adenosine deamination of pre-mRNA results in a change in the amino acid sequence of the gene product, which differs from that predicted by the genomic DNA sequence. Other members of this family include DRADA (ADAR; 146920) and RED1 (ADARB1; 601218) (Mittaz et al., 1997).
Melcher et al. (1996) cloned rat Red2. Red2 is 54 amino acids longer than Red1 at the N terminus. Both Red1 and Drada were expressed in brain and in peripheral tissues; however, RED2 transcripts were found only in brain by Northern blot analysis.
By searching EST databases using the catalytic domain of human ADAR1 (ADAR), Chen et al. (2000) identified ADARB2, which they called ADAR3. The deduced 739-amino acid protein contains an N-terminal R domain, followed by 2 dsRNA-binding motifs and a C-terminal deaminase domain. The R domain is an arginine- and lysine-rich region that includes 6 consecutive arginine residues. ADAR3 shares 72% amino acid similarity with ADAR2 (ADARB1) and is 84% identical to rat Adar3. Northern blot analysis of several tissues detected a major 9.5-kb transcript only in brain. Within specific brain regions, thalamus and amygdala showed highest expression. Western blot analysis of total mouse brain detected Adar3 at an apparent molecular mass of 81 kD.
Melcher et al. (1996) found that both rat Red1 and Drada were able to edit RNAs encoding glutamate receptor subunits (GluRs), but they found no editing activity of GluR mRNAs for rat Red2 in vitro.
Chen et al. (2000) were unable to detect RNA-editing activity by human ADAR3, consistent with the results in rat. However, ADAR3 bound dsRNA and single-stranded RNA (ssRNA). Deletion mutagenesis determined that the N-terminal arginine-rich region of ADAR3 mediated its binding to ssRNA. ADAR3 also inhibited in vitro RNA editing by other ADAR family members. Chen et al. (2000) hypothesized that ADAR3 may have a regulatory role in RNA editing.
By somatic cell hybrid analysis, Mittaz et al. (1997) mapped the RED2 gene to chromosome 10p15.
Chen, C.-X., Cho, D.-S. C., Wang, Q., Lai, F., Carter, K. C., Nishikura, K. A third member of the RNA-specific adenosine deaminase gene family, ADAR3, contains both single- and double-stranded RNA binding domains. RNA 6: 755-767, 2000. [PubMed: 10836796] [Full Text: https://doi.org/10.1017/s1355838200000170]
Melcher, T., Maas, S., Herb, A., Sprengel, R., Higuchi, M., Seeburg, P. H. RED2, a brain-specific member of the RNA-specific adenosine deaminase family. J. Biol. Chem. 271: 31795-31798, 1996. [PubMed: 8943218] [Full Text: https://doi.org/10.1074/jbc.271.50.31795]
Mittaz, L., Antonarakis, S. E., Higuchi, M., Scott, H. S. Localization of a novel human RNA-editing deaminase (hRED2 or ADARB2) to chromosome 10p15. Hum. Genet. 100: 398-400, 1997. [PubMed: 9272162] [Full Text: https://doi.org/10.1007/s004390050523]