Chromatin-specific regulation of mammalian rDNA transcription by clustered TTF-I binding sites.

ABSTRACT: Enhancers and promoters often contain multiple binding sites for the same transcription factor, suggesting that homotypic clustering of binding sites may serve a role in transcription regulation. Here we show that clustering of binding sites for the transcription termination factor TTF-I downstream of the pre-rRNA coding region specifies transcription termination, increases the efficiency of transcription initiation and affects the three-dimensional structure of rRNA genes. On chromatin templates, but not on free rDNA, clustered binding sites promote cooperative binding of TTF-I, loading TTF-I to the downstream terminators before it binds to the rDNA promoter. Interaction of TTF-I with target sites upstream and downstream of the rDNA transcription unit connects these distal DNA elements by

SUBMITTER: Diermeier SD 

PROVIDER: S-EPMC3772059 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature