Abstract
From insects to mammals, metallothionein genes are induced in response to heavy metal load by the transcription factor MTF-1, which binds to short DNA sequence motifs, termed metal response elements (MREs). Here we describe a novel and seemingly paradoxical role for MTF-1 in Drosophila in that it also mediates transcriptional activation of Ctr1B, a copper importer, upon copper depletion. Activation depends on the same type of MRE motifs in the upstream region of the Ctr1B gene as are normally required for metal induction. Thus, a single transcription factor, MTF-1, plays a direct role in both copper detoxification and acquisition by inducing the expression of metallothioneins and of a copper importer, respectively.
Publication types
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Comparative Study
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Biological Transport / physiology
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Cation Transport Proteins / metabolism*
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Cells, Cultured
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Computational Biology
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Copper / metabolism*
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Copper Transporter 1
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DNA-Binding Proteins
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Drosophila / metabolism*
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Electrophoretic Mobility Shift Assay
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Gene Components
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Gene Expression Regulation*
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Green Fluorescent Proteins
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Ion Transport / physiology
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Metallothionein / metabolism
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Protein Binding
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Transcription Factor MTF-1
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Transcription Factors / metabolism*
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Transfection
Substances
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Cation Transport Proteins
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Copper Transporter 1
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DNA-Binding Proteins
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Transcription Factors
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enhanced green fluorescent protein
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Green Fluorescent Proteins
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Copper
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Metallothionein