title: The evolutionarily conserved iron-sulfur protein INDH is required for complex I assembly and mitochondrial translation in Arabidopsis [corrected].
abstract: The assembly of respiratory complexes is a multistep process, requiring coordinate expression of mitochondrial and nuclear genes and cofactor biosynthesis. We functionally characterized the iron-sulfur protein required for NADH dehydrogenase (INDH) in the model plant Arabidopsis thaliana. An indh knockout mutant lacked complex I but had low levels of a 650-kD assembly intermediate, similar to mutations in the homologous NUBPL (nucleotide binding protein-like) in Homo sapiens. However, heterozygous indh/+ mutants displayed unusual phenotypes during gametogenesis and resembled mutants in mitochondrial translation more than mutants in complex I. Gradually increased expression of INDH in indh knockout plants revealed a significant delay in reassembly of complex I, suggesting an indirect role for INDH in the assembly process. Depletion of INDH protein was associated with decreased (35)S-Met labeling of translation products in isolated mitochondria, whereas the steady state levels of several mitochondrial transcripts were increased. Mitochondrially encoded proteins were differentially affected, with near normal levels of cytochrome c oxidase subunit2 and Nad7 but little Nad6 protein in the indh mutant. These data suggest that INDH has a primary role in mitochondrial translation that underlies its role in complex I assembly.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom.
authors.forename: Mateusz M
authors.initials: MM
authors.lastname: Wydro
authors.forename: Pia
authors.initials: P
authors.lastname: Sharma
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Foster
authors.forename: Katrine
authors.initials: K
authors.lastname: Bych
authors.forename: Etienne H
authors.initials: EH
authors.lastname: Meyer
authors.forename: Janneke
authors.initials: J
authors.lastname: Balk
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D042967:Electron Transport Complex I / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D055503:Protein Multimerization
chemical_list: D029681:Arabidopsis Proteins; D007506:Iron-Sulfur Proteins; D024101:Mitochondrial Proteins; D042967:Electron Transport Complex I