Abstract
Here we have examined HIV-1 nucleosome remodeling upon the binding of transcription factors and the SWI/SNF complex using a novel approach. The approach combines UV laser protein-DNA crosslinking, electrophoretic mobility-shift analysis and DNase I protection analysis with immunochemical techniques. It was found that single activator-bound HIV-1 nucleosomes exhibit very weak perturbation in histone NH(2) tail-DNA interactions. However, the simultaneous binding of the transcription activators Sp1, NF-kB1, LEF-1 and USF synergistically increased the release of histone NH(2) tails from nucleosomal DNA. In contrast, the binding of SWI/SNF complex to HIV-1 nucleosome disrupted structured histone domain-DNA contacts, but not histone NH(2) tail-DNA interactions. Stable remodeled nucleosomes, (obtained after detachment of SWI/SNF), displayed identical structural alterations with those bound to SWI/SNF. These results demonstrate a different in vitro remodeling of the HIV-1 nucleosome upon the binding of multiple transcription activators and of SWI/SNF complex.
Copyright 2000 Academic Press.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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DNA Footprinting
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DNA Helicases
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DNA, Viral / chemistry
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DNA, Viral / genetics
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DNA, Viral / metabolism
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DNA-Binding Proteins / metabolism*
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Deoxyribonuclease I / metabolism
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Gene Expression Regulation, Viral
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HIV-1 / genetics*
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Histones / chemistry
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Histones / metabolism
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Humans
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Lasers
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Lymphoid Enhancer-Binding Factor 1
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Macromolecular Substances
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NF-kappa B / metabolism
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Nuclear Proteins*
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Nucleic Acid Conformation*
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Nucleosomes / chemistry*
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Nucleosomes / genetics
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Nucleosomes / metabolism*
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Precipitin Tests
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Protein Binding
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Sp1 Transcription Factor / metabolism
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Trans-Activators / metabolism*
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Transcription Factors / metabolism*
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Transcription, Genetic / genetics
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Ultraviolet Rays
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Upstream Stimulatory Factors
Substances
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DNA, Viral
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DNA-Binding Proteins
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Histones
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LEF1 protein, human
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Lymphoid Enhancer-Binding Factor 1
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Macromolecular Substances
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NF-kappa B
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Nuclear Proteins
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Nucleosomes
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SMARCA1 protein, human
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SMARCA2 protein, human
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Sp1 Transcription Factor
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Trans-Activators
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Transcription Factors
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USF1 protein, human
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Upstream Stimulatory Factors
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Deoxyribonuclease I
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SMARCA4 protein, human
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DNA Helicases