title: Inosine cyanoethylation identifies A-to-I RNA editing sites in the human transcriptome.
abstract: Adenosine-to-inosine (A-to-I) RNA editing is a post-transcriptional processing event involved in diversifying the transcriptome responsible for various biological processes. Although bioinformatic approaches have predicted a number of A-to-I editing sites in cDNAs, the human transcriptome is thought to still harbor large numbers of as-yet-unknown editing sites. Exploring new editing sites requires a biochemical method to accurately identify inosines on RNA strands. We here describe a chemical method to identify inosines, called inosine chemical erasing (ICE), that is based on cyanoethylation combined with reverse transcription. We carried out a large-scale verification of the ICE method focusing on 642 regions in human cDNA and identified 5,072 editing sites, including 4,395 new sites. Functional study revealed that A-to-I intronic editing in the SARS gene mediated by ADAR1 is involved in preventing aberrant exonization of Alu sequence into mature mRNA.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sakurai
authors.forename: Takanori
authors.initials: T
authors.lastname: Yano
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kawabata
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000241:Adenosine / Q000737:chemistry / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000235:genetics; D000478:Alkylation; D020087:Alu Elements / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D005091:Exons / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D007288:Inosine / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D017393:RNA Editing / Q000235:genetics*; D016601:RNA-Binding Proteins; D012714:Serine-tRNA Ligase / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D016601:RNA-Binding Proteins; D007288:Inosine; C567955:ADARB1 protein, human; D000243:Adenosine Deaminase; D012714:Serine-tRNA Ligase; D000241:Adenosine