title: A study of new Arabidopsis chloroplast RNA editing mutants reveals general features of editing factors and their target sites.
abstract: RNA editing in higher plant organelles results in the conversion of specific cytidine residues to uridine residues in RNA. The recognition of a specific target C site by the editing machinery involves trans-acting factors that bind to the RNA upstream of the C to be edited. In the last few years, analysis of mutants affected in chloroplast biogenesis has identified several pentatricopeptide repeat (PPR) proteins from the PLS subfamily that are essential for the editing of particular RNA transcripts. We selected other genes from the same subfamily and used a reverse genetics approach to identify six new chloroplast editing factors in Arabidopsis thaliana (OTP80, OTP81, OTP82, OTP84, OTP85, and OTP86). These six factors account for nine editing sites not previously assigned to an editing factor and, together with the nine PPR editing proteins previously described, explain more than half of the 34 editing events in Arabidopsis chloroplasts. OTP80, OTP81, OTP85, and OTP86 target only one editing site each, OTP82 two sites, and OTP84 three sites in different transcripts. An analysis of the target sites requiring the five editing factors involved in editing of multiple sites (CRR22, CRR28, CLB19, OTP82, and OTP84) suggests that editing factors can generally distinguish pyrimidines from purines and, at some positions, must be able to recognize specific bases.
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, WA 6009, Crawley, Australia.
authors.forename: Kamel
authors.initials: K
authors.lastname: Hammani
authors.forename: Kenji
authors.initials: K
authors.lastname: Okuda
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Tanz
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Chateigner-Boutin
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Shikanai
authors.forename: Ian
authors.initials: I
authors.lastname: Small
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008967:Molecular Biology / Q000379:methods; D009154:Mutation / Q000235:genetics*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics; D017393:RNA Editing / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors