Pax-8, a paired domain-containing protein, binds to a sequence overlapping the recognition site of a homeodomain and activates transcription from two thyroid-specific promoters.
The Pax-8 gene, a member of the murine family of paired box-containing genes (Pax genes), is expressed in adult thyroid and in cultured thyroid cell lines. The Pax-8 protein binds, through its paired domain, to the promoters of thyroglobulin and thyroperoxidase, genes that are exclusively expressed in the thyroid. In both promoters, the binding site of Pax-8 overlaps with that of TTF-1, a homeodomain-containing protein involved in the activation of thyroid-specific transcription. Pax-8 activates transcription from cotransfected thyroperoxidase and thyroglobulin promoters, indicating that it may be involved in the establishment, control, or maintenance of the thyroid-differentiated phenotype. Thus, the promoters of thyroglobulin and thyroperoxidase represent the first identified natural targets for transcriptional activation by a paired domain-containing protein.
Zannini
M
M
European Molecular Biology Laboratory, Heidelberg, Germany.
Francis-Lang
H
H
Plachov
D
D
Di Lauro
R
R
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D004247:DNA; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000235:genetics; D011401:Promoter Regions, Genetic; D051381:Rats; D013954:Thyroglobulin / Q000235:genetics; D013961:Thyroid Gland / Q000201:enzymology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D014157:Transcription Factors; D004247:DNA; D013954:Thyroglobulin; D010544:Peroxidases