Affordable Access

Molecular mechanisms mediating methylation-dependent silencing of ribosomal gene transcription.

Authors
  • Santoro, R
  • Grummt, I
Type
Published Article
Journal
Molecular Cell
Publisher
Elsevier
Publication Date
Sep 01, 2001
Volume
8
Issue
3
Pages
719–725
Identifiers
PMID: 11583633
Source
Medline
License
Unknown

Abstract

Epigenetic control mechanisms silence about half of ribosomal RNA genes (rDNA) in metabolically active cells. In the mouse, 40% of rDNA repeats are methylated and can be activated by 5-azacytidine treatment. In exploring the effect of methylation on rDNA transcription, we found that methylation of a single CpG dinucleotide within the upstream control element of the rDNA promoter (at -133) abrogates rDNA transcription both in transfection experiments and in in vitro assays using chromatin templates. Chromatin immunoprecipitation assays demonstrate that methylation of the cytosine at -133 inhibits binding of the transcription factor UBF to nucleosomal rDNA, thereby preventing initiation complex formation. Thus, methylation may be a mechanism to inactivate rDNA genes and propagate transcriptional silencing through cell division.

Report this publication

Statistics

Seen <100 times