RNA polymerase I transcription on nucleosomal templates: the transcription termination factor TTF-I induces chromatin remodeling and relieves transcriptional repression.
Eukaryotic ribosomal gene promoters are preceded by a terminator element which is recognized by the transcription termination factor TTF-I. We have studied the function of this promoter-proximal terminator and show that binding of TTF-I is the key event which leads to ATP-dependent nucleosome remodeling and transcriptional activation of mouse rDNA pre-assembled into chromatin. We have analyzed TTF-I mutants for their ability to bind to free or nucleosomal DNA, and show that the DNA binding domain of TTF-I on its own is not sufficient for interaction with chromatin, indicating that specific protein features exist that endow a transcription factor with chromatin binding and remodeling properties. This first analysis of RNA polymerase I transcription in chromatin provides a clue for the function of the upstream terminator and establishes a dual role for TTF-I both as a termination factor and a chromatin-specific transcription activator.
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German Cancer Research Center, Division of Molecular Biology of the Cell II, Heidelberg, Germany.
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Becker
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Grummt
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D000818:Animals; D002474:Cell-Free System; D002843:Chromatin / Q000378:metabolism*; D018983:DNA Footprinting; D004275:DNA, Ribosomal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D051379:Mice; D009707:Nucleosomes / Q000378:metabolism; D012318:RNA Polymerase I / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D017384:Sequence Deletion; D013698:Templates, Genetic; D013728:Terminator Regions, Genetic / Q000235:genetics; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics / Q000502:physiology
D002843:Chromatin; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D009707:Nucleosomes; D012333:RNA, Messenger; D014157:Transcription Factors; C504004:Ttf1 protein, mouse; D012318:RNA Polymerase I