Yvh1 is required for a late maturation step in the 60S biogenesis pathway.
Before entering translation, preribosomal particles undergo sequential late maturation steps. In the case of pre-60S particles, these steps involve the release of shuttling maturation factors and transport receptors. In this study, we report a new maturation step in the 60S biogenesis pathway in budding yeast. We show that efficient release of the nucleolar/nuclear ribosomal-like protein Mrt4 (homologous to the acidic ribosomal P-protein Rpp0) from pre-60S particles requires the highly conserved protein Yvh1, which associates only with late pre-60S particles. Cell biological and biochemical analyses reveal that Mrt4 fails to dissociate from late pre-60S particles in yvh1Delta cells, inducing a delay in nuclear pre-ribosomal RNA processing and a pre-60S export defect in yvh1Delta cells. Moreover, we have isolated gain of function alleles of Mrt4 that specifically bypass the requirement for Yvh1 and rescue all yvh1Delta-associated phenotypes. Together, our data suggest that Yvh1-mediated release of Mrt4 precedes cytoplasmic loading of Rpp0 on pre-60S particles and is an obligatory late step toward construction of translation-competent 60S subunits.
Institute of Biochemistry, ETH Zürich, CH-8093 Zürich, Switzerland.
Stefan
S
Kemmler
Laura
L
Occhipinti
Maria
M
Veisu
Vikram Govind
VG
Panse
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D001665:Binding Sites; D054637:Dual-Specificity Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005838:Genotype; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011487:Protein Conformation; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D054683:Ribosome Subunits, Large, Eukaryotic / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
C121972:MRT4 protein, S cerevisiae; C056002:RPP0 protein, S cerevisiae; D012269:Ribosomal Proteins; C525863:Rpl12 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D054637:Dual-Specificity Phosphatases; C121559:YVH1 protein, S cerevisiae