p53 Transcriptional Activation Mediated by Coactivators TAF II 40 and TAF II 60

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Abstract
The tumor suppressor protein p53 is a transcriptional regulator that enhances the expression of proteins that control cellular proliferation. The multisubunit transcription factor IID (TFIID) is thought to be a primary target for site-specific activators of transcription. Here, a direct interaction between the activation domain of p53 and two subunits of the TFIID complex, TAFII40 and TAFII60, is reported. A double point mutation in the activation domain of p53 impaired the ability of this domain to activate transcription and, simultaneously, its ability to interact with both TAFII40 and TAFII60. Furthermore, a partial TFIID complex containing Drosophila TATA binding protein (dTBP), human TAFII250, dTAFII60, and dTAFII40 supported activation by a Gal4-p53 fusion protein in vitro, whereas TBP or a subcomplex lacking TAFII40 and TAFII60 did not. Together, these results suggest that TAFII40 and TAFII60 are important targets for transmitting activation signals between p53 and the initiation complex.