Biogenesis of cytosolic ribosomes requires the essential iron-sulphur protein Rli1p and mitochondria.
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.
Kispal
Gyula
G
Institute of Biochemistry, University Medical School of Pecs, Hungary.
Sipos
Katalin
K
Lange
Heike
H
Fekete
Zsuzsanna
Z
Bedekovics
Tibor
T
Janáky
Tamás
T
Bassler
Jochen
J
Aguilar Netz
Daili J
DJ
Balk
Janneke
J
Rotte
Carmen
C
Lill
Roland
R
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001693:Biological Transport, Active; D003600:Cytosol / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D005800:Genes, Fungal; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D018528:ATP-Binding Cassette Transporters; D004271:DNA, Fungal; C121939:HCR1 protein, S cerevisiae; D007506:Iron-Sulfur Proteins; D010448:Peptide Initiation Factors; C492990:RLI1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins