Nucleolar KKE/D repeat proteins Nop56P and Nop58P interact with Nop1p and are required for ribosome biogenesis

Different point mutations in the nucleolar protein fibrillarin (Nop1p in Saccharomyces cerevisiae) can inhibit different steps in ribosome synthesis. A screen for mutations that are synthetically lethal (sl) with the nop1-5 allele, which inhibits pre-rRNA processing, identified NOP56. An independent...

Full description

Saved in:
Bibliographic Details
Main Authors: Gautier, Thierry (Author) , Bergès, Thierry (Author) , Tollervey, David (Author) , Hurt, Ed (Author)
Format: Article (Journal)
Language:English
Published: 1997
In: Molecular and cellular biology
Year: 1997, Volume: 17, Issue: 12, Pages: 7088-7098
ISSN:1098-5549
DOI:10.1128/MCB.17.12.7088
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1128/MCB.17.12.7088
Get full text
Author Notes:Thierry Gautier, Thierry Bergès, David Tollervey, Ed Hurt
Description
Summary:Different point mutations in the nucleolar protein fibrillarin (Nop1p in Saccharomyces cerevisiae) can inhibit different steps in ribosome synthesis. A screen for mutations that are synthetically lethal (sl) with the nop1-5 allele, which inhibits pre-rRNA processing, identified NOP56. An independent sl mutation screen with nop1-3, which inhibits pre-rRNA methylation, identified a mutation in NOP58. Strikingly, Nop56p and Nop58p are highly homologous (45% identity). Both proteins were found to be essential and localized to the nucleolus. A temperature-sensitive lethal mutant allele, nop56-2, inhibited many steps in pre-rRNA processing, particularly on the pathway of 25S/5.8S rRNA synthesis, and led to defects in 60S subunit assembly. Epitope-tagged constructs show that both Nop56p and Nop58p are associated with Noplp in complexes, Nop56p and Nop1p exhibiting a stoichiometric association. These physical interactions presumably underlie the observed sl phenotypes. Well-conserved homologs are present in a range of organisms, including humans (52% identity between human hNop56p and yeast Nop56p), suggesting that these complexes have been conserved in evolution.
Item Description:Elektronische Reproduktion der Druck-Ausgabe 29. März 2023
Gesehen am 01.12.2025
Physical Description:Online Resource
ISSN:1098-5549
DOI:10.1128/MCB.17.12.7088