title: The PPR protein SLOW GROWTH 4 is involved in editing of nad4 and affects the splicing of nad2 intron 1.
abstract: SLO4 is a mitochondrial PPR protein that is involved in editing nad4, possibly required for the efficient splicing of nad2 intron1. Pentatricopeptide repeat (PPR) proteins constitute a large protein family in flowering plants and are thought to be mostly involved in organellar RNA metabolism. The subgroup of PLS-type PPR proteins were found to be the main specificity factors of cytidine to uridine RNA editing. Identifying the targets of PLS-type PPR proteins can help in elucidating the molecular function of proteins encoded in the organellar genomes. In this study, plants lacking the SLOW GROWTH 4 PPR protein were characterized. Slo4 mutants were characterized as having restricted root growth, being late flowering and displaying an overall delayed growth phenotype. Protein levels and activity of mitochondrial complex I were decreased and putative complex I assembly intermediates accumulated in the mutant plants. An editing defect, leading to an amino acid change, in the mitochondrial nad4 transcript, encoding for a complex I subunit, was identified. Furthermore, the splicing efficiency of the first intron of nad2, encoding for another complex I subunit, was also decreased. The change in splicing efficiency could however not be linked to any editing defects in the nad2 transcript.
authors.affiliation: Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Großhaderner Strasse 2-4, 82152, Planegg-Martinsried, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weißenberger
authors.affiliation: Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Großhaderner Strasse 2-4, 82152, Planegg-Martinsried, Germany.|Munich Center for Integrated Protein Science, CiPSM, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377, Munich, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Soll
authors.affiliation: Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Großhaderner Strasse 2-4, 82152, Planegg-Martinsried, Germany. christopher.carrie@lmu.de.
authors.forename: Chris
authors.identifier: http://orcid.org/0000-0002-4240-4674
authors.initials: C
authors.lastname: Carrie
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D042967:Electron Transport Complex I / Q000235:genetics* / Q000378:metabolism; D015151:Immunoblotting; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009245:NADH Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D030821:Plants, Genetically Modified; D017393:RNA Editing; D012326:RNA Splicing; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D029681:Arabidopsis Proteins; D024101:Mitochondrial Proteins; C000616519:SLO4 protein, Arabidopsis; C513204:NAD4 protein, Arabidopsis; D009245:NADH Dehydrogenase; C548935:ndhG protein, Arabidopsis; D042967:Electron Transport Complex I
keywords: Complex I; Mitochondria; Pentatricopeptide repeat; RNA editing; Splicing