The iron-sulphur protein Ind1 is required for effective complex I assembly.
NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial inner membrane is a multi-subunit protein complex containing eight iron-sulphur (Fe-S) clusters. Little is known about the assembly of complex I and its Fe-S clusters. Here, we report the identification of a mitochondrial protein with a nucleotide-binding domain, named Ind1, that is required specifically for the effective assembly of complex I. Deletion of the IND1 open reading frame in the yeast Yarrowia lipolytica carrying an internal alternative NADH dehydrogenase resulted in slower growth and strongly decreased complex I activity, whereas the activities of other mitochondrial Fe-S enzymes, including aconitase and succinate dehydrogenase, were not affected. Two-dimensional gel electrophoresis, in vitro activity tests and electron paramagnetic resonance signals of Fe-S clusters showed that only a minor fraction (approximately 20%) of complex I was assembled in the ind1 deletion mutant. Using in vivo and in vitro approaches, we found that Ind1 can bind a [4Fe-4S] cluster that was readily transferred to an acceptor Fe-S protein. Our data suggest that Ind1 facilitates the assembly of Fe-S cofactors and subunits of complex I.
Bych
Katrine
K
Department of Plant Sciences, University of Cambridge, Cambridge, UK.
Kerscher
Stefan
S
Netz
Daili J A
DJ
Pierik
Antonio J
AJ
Zwicker
Klaus
K
Huynen
Martijn A
MA
Lill
Roland
R
Brandt
Ulrich
U
Balk
Janneke
J
D003545:Cysteine / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D042967:Electron Transport Complex I / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D017353:Gene Deletion; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D025062:Yarrowia / Q000378:metabolism*
D005656:Fungal Proteins; D007506:Iron-Sulfur Proteins; D050505:Mutant Proteins; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron; D042967:Electron Transport Complex I; D003545:Cysteine