Analysis of RNA editing sites in Adar mutant mice. Mus musculus

Adenosine-to-inosine RNA editing is catalyzed by ADAR1 and ADAR2 in mammals. ADAR1 has two isoforms, short p110 and long p150. Although both ADAR1 KO mice and ADAR1 KI mice that harbor the editing-inactive E861A point mutation are embryonically lethal, this lethality can be rescued by concurrent deletion of MDA5. ADAR2 KO mice are also lethal during early postnatal stage, whereas this lethality can be rescued by insertion of a point mutation at the Q/R site of the glutamate GluA2 subunit to express edited GluA2 solely. Given that RNA editing is catalyzed by ADAR1 and ADAR2 either cooperatively or competitively, it is important to know whether each site is edited by two enzymes. Therefore, in this study, we examined and compared the editing ratio of each site in brain and thymus among various Adar mutant mice.