Dez C, et al. (2006) Surveillance of nuclear-restricted pre-ribosomes within a subnucleolar region of Saccharomyces cerevisiae. EMBO J 25(7):1534-46
Abstract: We previously hypothesized that HEAT-repeat (Huntington, elongation A subunit, TOR) ribosome synthesis factors function in ribosome export. We report that the HEAT-repeat protein Sda1p is a component of late 60S pre-ribosomes and is required for nuclear export of both ribosomal subunits. In strains carrying the ts-lethal sda1-2 mutation, pre-60S particles were rapidly degraded following transfer to 37 degrees C. Polyadenylated forms of the 27S pre-rRNA and the 25S rRNA were detected, suggesting the involvement of the Trf4p/Air/Mtr4p polyadenylation complex (TRAMP). The absence of Trf4p suppressed polyadenylation and stabilized the pre-rRNA and rRNA. The absence of the nuclear exosome component Rrp6p also conferred RNA stabilization, with some hyperadenylation. We conclude that the nuclear-restricted pre-ribosomes are polyadenylated by TRAMP and degraded by the exosome. In sda1-2 strains at 37 degrees C, pre-40S and pre-60S ribosomes initially accumulated in the nucleoplasm, but then strongly concentrated in a subnucleolar focus, together with exosome and TRAMP components. Localization of pre-ribosomes to this focus was lost in sda1-2 strains lacking Trf4p or Rrp6p. We designate this nucleolar focus the No-body and propose that it represents a site of pre-ribosome surveillance.
|Status: Published||Type: Journal Article | Research Support, Non-U.S. Gov't||PubMed ID: 16541108|
Topics addressed in this paper
Number of different genes curated to this paper: 13
- To go to the Locus page for a gene, click on the gene name.
|Topics||Genes (#1 - 10 )|
|Topics||Genes (#11 - 13 )|
|Protein-Nucleic Acid Interactions|