An Open Chromatin Structure in a Liver-Specific Enhancer That Confers High Level Expression to Human Apolipoprotein B Transgenes in Mice
| Autor: | Sheryl A. Goodart, Travis J. Antes, Bernhard Paulweber, Beatriz Levy-Wilson, Soon-Youl Lee |
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| Rok vydání: | 2000 |
| Předmět: |
Apolipoprotein B
Molecular Sequence Data DNA Footprinting Mice Transgenic Mice Tumor Cells Cultured Animals Deoxyribonuclease I Humans Transgenes Binding site Nuclear protein Enhancer Molecular Biology Transcription factor Apolipoproteins B Cell Nucleus Binding Sites Base Sequence biology Sequence Analysis DNA Molecular biology Chromatin DNA binding site Enhancer Elements Genetic Liver Organ Specificity biology.protein Nucleic Acid Conformation 5' Untranslated Regions HeLa Cells Micrococcal nuclease |
| Zdroj: | Molecular Cell Biology Research Communications. 4:206-211 |
| ISSN: | 1522-4724 |
| DOI: | 10.1006/mcbr.2001.0279 |
| Popis: | A number of DNaseI-hypersensitive (DH) sites have been mapped within a regulatory region situated upstream of the human apolipoprotein B (apoB) promoter (−5262 to −899) that is required for high level expression of human apoB transgenes in the livers of mice. These DH sites were observed in nuclei from transcriptionally active liver-derived HepG2 cells, but were absent from transcriptionally inactive HeLa cell nuclei. Several nuclear protein binding sites were detected in the DNaseI-hypersensitive region by DNaseI footprinting with HepG2 nuclear extracts, representing putative binding sites for the liver-specific activators. The locations of binding sites for these transcription factors were revealed via computer analysis of the DNA sequence of this region against a transcription factor database. Many micrococcal nuclease hypersensitive (MH) sites were also observed in nuclei from HepG2 cells but not in HeLa cell nuclei, implying that in hepatic cells, nucleosomes are either absent or have been displaced from this region by the liver-specific transcriptional activators, as inferred by the correspondence between the DH sites, the MH sites and the footprints. |
| Databáze: | OpenAIRE |
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