title: Nob1p is required for cleavage of the 3' end of 18S rRNA.
abstract: We report the characterization of a novel factor, Nob1p (Yor056c), which is essential for the synthesis of 40S ribosome subunits. Genetic depletion of Nob1p strongly inhibits the processing of the 20S pre-rRNA to the mature 18S rRNA, leading to the accumulation of high levels of the 20S pre-rRNA together with novel degradation intermediates. 20S processing occurs within a pre-40S particle after its export from the nucleus to the cytoplasm. Consistent with a direct role in this cleavage, Nob1p was shown to be associated with the pre-40S particle and to be present in both the nucleus and the cytoplasm. This suggests that Nob1p accompanies the pre-40S ribosomes during nuclear export. Pre-40S export is not, however, inhibited by depletion of Nob1p.
authors.affiliation: Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fatica
authors.forename: Marlene
authors.initials: M
authors.lastname: Oeffinger
authors.forename: Mensur
authors.initials: M
authors.lastname: Dlakić
authors.forename: David
authors.initials: D
authors.lastname: Tollervey
mesh_terms: D021581:Active Transport, Cell Nucleus; D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003593:Cytoplasm / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005656:Fungal Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D009841:Oligonucleotides / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D012335:RNA, Ribosomal / Q000378:metabolism; D012337:RNA, Ribosomal, 18S / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013395:Sucrose / Q000494:pharmacology; D013997:Time Factors; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; C405962:NOB1 protein, S cerevisiae; D009687:Nuclear Proteins; D009841:Oligonucleotides; D012335:RNA, Ribosomal; D012337:RNA, Ribosomal, 18S; D029701:Saccharomyces cerevisiae Proteins; D013395:Sucrose