ADAR RNA editing enzymes (adenosine deaminases acting on RNA) that convert adenosine bases to inosines were first identified biochemically 30 years ago. Since then, studies on ADARs in genetic model organisms, and evolutionary comparisons between them, continue to reveal a surprising range of pleiotropic biological effects of ADARs. This review focuses on Drosophila melanogaster, which has a single Adar gene encoding a homolog of vertebrate ADAR2 that site-specifically edits hundreds of transcripts to change individual codons in ion channel subunits and membrane and cytoskeletal proteins. Drosophila ADAR is involved in the control of neuronal excitability and neurodegeneration and, intriguingly, in the control of neuronal plasticity and sleep. Drosophila ADAR also interacts strongly with RNA interference, a key antiviral defense mechanism in invertebrates. Recent crystal structures of human ADAR2 deaminase domain-RNA complexes help to interpret available information on Drosophila ADAR isoforms and on the evolution of ADARs from tRNA deaminase ADAT proteins. ADAR RNA editing is a paradigm for the now rapidly expanding range of RNA modifications in mRNAs and ncRNAs. Even with recent progress, much remains to be understood about these groundbreaking ADAR RNA modification systems.

• Keywords
• ADAR, Drosophila melanogaster, RNA editing, RNA modification, dsRNA, epitranscriptome,
• MeSH
• Adenosine Deaminase chemistry   genetics   metabolism   MeSH
• Drosophila melanogaster genetics   metabolism   MeSH
• RNA Editing * MeSH
• Gene Expression MeSH
• Protein Interaction Domains and Motifs MeSH
• Isoenzymes MeSH
• Humans MeSH
• RNA, Messenger genetics   MeSH
• Evolution, Molecular MeSH
• Nervous System metabolism   MeSH
• Vertebrates MeSH
• Drosophila Proteins genetics   metabolism   MeSH
• RNA-Binding Proteins genetics   metabolism   MeSH
• RNA Interference MeSH
• Substrate Specificity MeSH
• Protein Binding MeSH
• Structure-Activity Relationship MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Adar protein, Drosophila MeSH Browser
• Adenosine Deaminase MeSH
• Isoenzymes MeSH
• RNA, Messenger MeSH
• Drosophila Proteins MeSH
• RNA-Binding Proteins MeSH