title: AEF1/MPR25 is implicated in RNA editing of plastid atpF and mitochondrial nad5, and also promotes atpF splicing in Arabidopsis and rice.
abstract: RNA editing is an essential mechanism that modifies target cytidines to uridine in both mitochondrial and plastid mRNA. Target sites are recognized by pentatricopeptide repeat (PPR) proteins. Using bioinformatics predictions based on the code describing sequence recognition by PPR proteins, we have identified an Arabidopsis editing factor required for editing of atpF in plastids. A loss-of-function mutation in ATPF EDITING FACTOR 1 (AEF1, AT3G22150) results in severe variegation, presumably due to decreased plastid ATP synthase levels. Loss of editing at the atpF site is coupled with a large decrease in splicing of the atpF transcript, even though the editing site is within an exon and 53 nucleotides distant from the splice site. The rice orthologue of AEF1, MPR25, has been reported to be required for editing of a site in mitochondrial nad5 transcripts, and we confirm that editing of the same site is affected in the Arabidopsis aef1 mutant. We also show that splicing of chloroplast atpF transcripts is affected in the rice mpr25 mutant. AEF1 is thus highly unusual for an RNA editing specificity factor in that it has functions in both organelles.
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Aaron
authors.initials: A
authors.lastname: Yap
authors.forename: Peter
authors.initials: P
authors.lastname: Kindgren
authors.forename: Catherine
authors.initials: C
authors.lastname: Colas des Francs-Small
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kazama
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Tanz
authors.forename: Kinya
authors.initials: K
authors.lastname: Toriyama
authors.forename: Ian
authors.initials: I
authors.lastname: Small
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060365:Chloroplast Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018087:Plastids / Q000235:genetics / Q000378:metabolism; D017393:RNA Editing; D012326:RNA Splicing; D018747:RNA, Chloroplast / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C000603557:AEF1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D010940:Plant Proteins; D018747:RNA, Chloroplast; D012333:RNA, Messenger; D014157:Transcription Factors
keywords: ATP synthase; Arabidopsis thaliana; RNA editing; chloroplast; dual targeting; mitochondria; splicing