Fob1p recruits DNA topoisomerase I to ribosomal genes locus and contributes to its transcriptional silencing maintenance

[Display omitted] •Top1p is recruited at rDNA by Fob1p at only RBF region.•Fob1p contributes to transcriptional silencing at E-PRO recruiting Top1p that, in turn, recruits Sir2p.•Two silencing mechasnims at rDNA exist involving Fob1-Top1-Sir2 at RFB and RNA Pol I-Net1p-Sir2p at C-PRO respectively. S...

Full description

Saved in:
Bibliographic Details
Published in:The international journal of biochemistry & cell biology 2019-05, Vol.110, p.143-148
Main Authors: Di Felice, Francesca, Egidi, Alessandra, D'Alfonso, Anna, Camilloni, Giorgio
Format: Article
Language:English
Subjects:
DNA Replication - genetics
DNA topoisomerase I
DNA Topoisomerases, Type I - metabolism
DNA-Binding Proteins - metabolism
Fob1p
Gene Silencing
Genetic Loci - genetics
Nsr1p
Replication fork barrier
Ribosomes - genetics
RNA, Ribosomal - genetics
S. cerevisiae
Saccharomyces cerevisiae - cytology
Saccharomyces cerevisiae - enzymology
Saccharomyces cerevisiae - genetics
Saccharomyces cerevisiae Proteins - metabolism
Transcription, Genetic - genetics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Top1p is recruited at rDNA by Fob1p at only RBF region.•Fob1p contributes to transcriptional silencing at E-PRO recruiting Top1p that, in turn, recruits Sir2p.•Two silencing mechasnims at rDNA exist involving Fob1-Top1-Sir2 at RFB and RNA Pol I-Net1p-Sir2p at C-PRO respectively. S. cerevisiae ribosomal DNA (rDNA) locus hosts a series of highly complex regulatory machineries for RNA polymerase I, II and III transcription, DNA replication and units recombination, all acting in the Non Transcribed Spacers (NTSs) interposed between the repeated units by which it is composed. DNA topoisomerase I (Top1p) contributes, recruiting Sir2p, to the maintenance of transcriptional silencing occurring at the RNA Polymerase II cryptic promoters, located in the NTS region. In this paper we found that Fob1p presence is crucial for Top1p recruitment at NTS, allowing transcriptional silencing to be established and maintained. We also showed the role of Nsr1p in Top1p recruitment to rDNA locus. Our work allows to hypothesize that Nsr1p targets Top1p into the nucleolus while Fob1p is responsible for its preferential distribution at RFB.
ISSN:1357-2725
1878-5875
DOI:10.1016/j.biocel.2019.03.006