Specific Binding of High-Mobility-Group I (HMGI) Protein and Histone H1 to the Upstream AT-Rich Region of the Murine Beta Interferon Promoter: HMGI Protein Acts as a Potential Antirepressor of the Promoter
| Autor: | Eliette Bonnefoy, Janine Doly, Marie-Thérèse Bandu |
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| Rok vydání: | 1999 |
| Předmět: |
Molecular Sequence Data
DNA Footprinting Response Elements Histones Mice Histone H1 Transcription (biology) Animals HMGA1a Protein Binding site Promoter Regions Genetic Scaffold/matrix attachment region Molecular Biology Transcription factor Transcriptional Regulation Binding Sites Base Sequence biology DNA Superhelical Adenine Distamycins High Mobility Group Proteins Promoter Interferon-beta Cell Biology Molecular biology Chromatin Histone Gene Expression Regulation Mutation biology.protein Thymine Protein Binding Transcription Factors |
| Zdroj: | Molecular and Cellular Biology. 19:2803-2816 |
| ISSN: | 1098-5549 |
| Popis: | The high-mobility-group I (HMGI) protein is a nonhistone component of active chromatin. In this work, we demonstrate that HMGI protein specifically binds to the AT-rich region of the murine beta interferon (IFN-beta) promoter localized upstream of the murine virus-responsive element (VRE). Contrary to what has been described for the human promoter, HMGI protein did not specifically bind to the VRE of the murine IFN-beta promoter. Stably transfected promoters carrying mutations on this HMGI binding site displayed delayed virus-induced kinetics of transcription. When integrated into chromatin, the mutated promoter remained repressed and never reached normal transcriptional activity. Such a phenomenon was not observed with transiently transfected promoters upon which chromatin was only partially reconstituted. Using UV footprinting, we show that the upstream AT-rich sequences of the murine IFN-beta promoter constitute a preferential binding region for histone H1. Transfection with a plasmid carrying scaffold attachment regions as well as incubation with distamycin led to the derepression of the IFN-beta promoter stably integrated into chromatin. In vitro, HMGI protein was able to displace histone H1 from the upstream AT-rich region of the wild-type promoter but not from the promoter carrying mutations on the upstream high-affinity HMGI binding site. Our results suggest that the binding of histone H1 to the upstream AT-rich region of the promoter might be partly responsible for the constitutive repression of the promoter. The displacement by HMGI protein of histone H1 could help to convert the IFN-beta promoter from a repressed to an active state. |
| Databáze: | OpenAIRE |
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