Epigenetic regulation of TTF-I-mediated promoter-terminator interactions of rRNA genes.
EMBO J
; 27(8): 1255-65, 2008 Apr 23.
Article
em En
| MEDLINE
| ID: mdl-18354495
ABSTRACT
Ribosomal RNA synthesis is the eukaryotic cell's main transcriptional activity, but little is known about the chromatin domain organization and epigenetics of actively transcribed rRNA genes. Here, we show epigenetic and spatial organization of mouse rRNA genes at the molecular level. TTF-I-binding sites subdivide the rRNA transcription unit into functional chromatin domains and sharply delimit transcription factor occupancy. H2A.Z-containing nucleosomes occupy the spacer promoter next to a newly characterized TTF-I-binding site. The spacer and the promoter proximal TTF-I-binding sites demarcate the enhancer. DNA from both the enhancer and the coding region is hypomethylated in actively transcribed repeats. 3C analysis revealed an interaction between promoter and terminator regions, which brings the beginning and end of active rRNA genes into close contact. Reporter assays show that TTF-I mediates this interaction, thereby linking topology and epigenetic regulation of the rRNA genes.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
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Regiões Promotoras Genéticas
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Regiões Terminadoras Genéticas
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Genes de RNAr
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Epigênese Genética
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Proteínas de Ligação a DNA
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article