Abstract
Chromatin insulators affect interactions between promoters and enhancers/silencers and function as barriers for spreading of repressive chromatin. The Su(Hw) protein is responsible for activity of the best-studied Drosophila insulators. Here we demonstrate that an evolutionarily conserved protein, E(y)2/Sus1, is recruited to the Su(Hw) insulators via binding to the zinc-finger domain of Su(Hw). Partial inactivation of E(y)2 in a weak mutation, e(y)2(u1), impairs only the barrier, but not the enhancer-blocking, activity of the Su(Hw) insulators. Whereas neither su(Hw)(-) nor e(y)2(u1) affects fly viability, their combination proves lethal, testifying to functional interaction between Su(Hw) and E(y)2 in vivo. Apparently, different domains of Su(Hw) recruit proteins responsible for enhancer-blocking and for the barrier activity.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Genetically Modified
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Binding Sites
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Conserved Sequence
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / genetics*
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DNA-Binding Proteins / metabolism*
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Drosophila / genetics*
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Drosophila / metabolism*
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Drosophila Proteins / chemistry
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Drosophila Proteins / genetics*
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Drosophila Proteins / metabolism*
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Evolution, Molecular
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Genes, Insect
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Mutation
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Repressor Proteins / chemistry
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Repressor Proteins / genetics*
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Repressor Proteins / metabolism*
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Transcription Factors / chemistry
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Transcription Factors / genetics*
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Transcription Factors / metabolism*
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Two-Hybrid System Techniques
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Zinc Fingers
Substances
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DNA-Binding Proteins
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Drosophila Proteins
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Recombinant Proteins
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Repressor Proteins
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Transcription Factors
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e(y)2 protein, Drosophila
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su(Hw) protein, Drosophila