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Epigenetic regulation of TTF‐I‐mediated promoter–terminator interactions of rRNA genes
Author(s) -
Németh Attila,
Guibert Sylvain,
Tiwari Vijay Kumar,
Ohlsson Rolf,
Längst Gernot
Publication year - 2008
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2008.57
Subject(s) - biology , genetics , epigenetics , gene , terminator (solar) , promoter , ribosomal rna , microbiology and biotechnology , gene expression , ionosphere , physics , astronomy
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.