Role for p300 in Pax 8 induction of thyroperoxidase gene expression.
The nuclear p300 protein functions as a co-activator of gene transcription. Here we show that p300 works as a co-activator of the transcription factor Pax 8 on the thyroperoxidase gene promoter. Consistent with its role as co-activator, p300 potentiates Pax 8-activated transcription. Furthermore, we provide evidence supporting the formation of a complex between both factors in vivo and in vitro. This interaction involves the amino-terminal and CH3 domains of p300 and the trans-activation domain of Pax 8 at its carboxyl-terminal end. We show that the CH3 domain is crucial for the co-activator role of p300 on the thyroperoxidase gene promoter. In agreement with our finding and with the ability of the adenoviral protein E1A to bind p300, we show that E1A down-regulates Pax 8 activity.
Laboratory of Molecular Pathology and Ultrastructure, Regina Elena Cancer Institute, Via delle Messi d'Oro 156, 00158 Rome, Italy.
R
R
De Leo
S
S
Miccadei
E
E
Zammarchi
D
D
Civitareale
D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D007453:Iodide Peroxidase / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; D011485:Protein Binding; D015534:Trans-Activators / Q000378:metabolism / Q000502:physiology*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors; D015534:Trans-Activators; D007453:Iodide Peroxidase