The E-Class PPR Protein MEF3 of Arabidopsis thaliana Can Also Function in Mitochondrial RNA Editing With an Additional DYW Domain

• Published in: Plant and cell physiology 2012-02, Vol.53 (2), p.358-367
• Main Authors: Verbitskiy, Daniil, Merwe, Johannes A. van der, Zehrmann, Anja, Härtel, Barbara, Takenaka, Mizuki
• Format: Article
• Language: English
• Subjects: Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Base Sequence; Chromosome Mapping; DNA, Bacterial; Ecotype; Genetic Complementation Test; Mitochondria - genetics; Mitochondria - metabolism; Molecular Sequence Data; Mutagenesis, Insertional; Protein Interaction Domains and Motifs; RNA Editing; RNA, Plant - metabolism; Vitis vinifera
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcr182

In plants, RNA editing is observed in mitochondria and plastids, changing selected C nucleotides into Us in both organelles. We here identify the PPR (pentatricopeptide repeat) protein MEF3 (mitochondrial editing factor 3) of the E domain PPR subclass by genetic mapping of a variation between ecotypes Columbia (Col) and Landsberg erecta (Ler) in Arabidopsis thaliana to be required for a specific RNA editing event in mitochondria. The Ler variant of MEF3 differs from Col in two amino acids in repeats 9 and 10, which reduce RNA editing levels at site atp4-89 to about 50% in Ler. In a T-DNA insertion line, editing at this site is completely lost. In Vitis vinifera the gene most similar to MEF3 continues into a DYW extension beyond the common E domain. Complementation assays with various combinations of PPR and E domains from the vine and A. thaliana proteins show that the vine E region can substitute for the A. thaliana E region with or without the DYW domain. These findings suggest that the additional DYW domain does not disturb the MEF3 protein function in mitochondrial RNA editing in A. thaliana.