PAX 8 activates the enhancer of the human thyroperoxidase gene.
In this study we report on a novel natural target of the paired domain transcription factor PAX 8 in the enhancer element of the human thyroperoxidase gene, one of the most important thyroid differentiation markers. It is the primary enzyme involved in thyroid hormone synthesis and PAX 8 has been previously identified as an activating factor of the rat thyroperoxidase gene promoter. In vitro, PAX 8 binds a cis element of the human enhancer and its exogenous expression induces the enhancer activity in co-transfection experiments in Cos-7 cells. When mutated at this binding site, the enhancer is no longer activated by PAX 8. Our finding strengthens the PAX 8 role in the maintenance of thyroid differentiation and in particular in the tissue-specific thyroperoxidase gene expression.
Esposito
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Istituto di Medicina Sperimentale, CNR, Viale C. Marx 15, 00137 Roma, Italy.
Miccadei
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Saiardi
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Civitareale
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D000818:Animals; D019556:COS Cells; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D009687:Nuclear Proteins; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; D010544:Peroxidases / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D013961:Thyroid Gland / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors; C499497:Pax8 protein, rat; D015534:Trans-Activators; D010544:Peroxidases