Abstract
Mitochondria perform a central function in the biogenesis of cellular iron-sulphur (Fe/S) proteins. It is unknown to date why this biosynthetic pathway is indispensable for life, the more so as no essential mitochondrial Fe/S proteins are known. Here, we show that the soluble ATP-binding cassette (ABC) protein Rli1p carries N-terminal Fe/S clusters that require the mitochondrial and cytosolic Fe/S protein biogenesis machineries for assembly. Mutations in critical cysteine residues of Rli1p abolish association with Fe/S clusters and lead to loss of cell viability. Hence, the essential character of Fe/S clusters in Rli1p explains the indispensable character of mitochondria in eukaryotes. We further report that Rli1p is associated with ribosomes and with Hcr1p, a protein involved in rRNA processing and translation initiation. Depletion of Rli1p causes a nuclear export defect of the small and large ribosomal subunits and subsequently a translational arrest. Thus, ribosome biogenesis and function are intimately linked to the crucial role of mitochondria in the maturation of the essential Fe/S protein Rli1p.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP-Binding Cassette Transporters / chemistry
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ATP-Binding Cassette Transporters / genetics
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ATP-Binding Cassette Transporters / metabolism*
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Amino Acid Sequence
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Base Sequence
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Biological Transport, Active
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Cytosol / metabolism
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DNA, Fungal / genetics
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Genes, Fungal
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Iron-Sulfur Proteins / chemistry
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Iron-Sulfur Proteins / genetics
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Iron-Sulfur Proteins / metabolism*
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Mitochondria / metabolism*
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Peptide Initiation Factors / genetics
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Peptide Initiation Factors / metabolism
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Protein Biosynthesis
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Protein Structure, Tertiary
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Ribosomes / metabolism*
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Saccharomyces cerevisiae / cytology
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Sequence Homology, Amino Acid
Substances
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ATP-Binding Cassette Transporters
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DNA, Fungal
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HCR1 protein, S cerevisiae
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Iron-Sulfur Proteins
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Peptide Initiation Factors
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RLI1 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins