Direct interaction between the transcriptional activation domain of human p53 and the TATA box-binding protein.

R Truant,H Xiao,C.J Ingles,J Greenblatt

doi:10.1016/s0021-9258(18)53769-8

Abstract

The human p53 tumor suppressor gene product can activate transcription by RNA polymerase II in the yeast, Saccharomyces cerevisiae, as well as in human cells. Several viral transcriptional activator proteins have been shown to directly contact TBP, the TATA box-binding subunit of the general initiation factor, TFIID. In this report, we use protein affinity chromatography to show that the cellular transcription factor, p53, interacts directly and specifically with yeast TBP. The TBP binding domain of p53 was localized to its N-terminal 73 amino acids. This highly acidic portion of p53 functions as a transcriptional activation domain and is deleted in some tumors induced by the Friend leukemia virus. A human tumor-derived oncogenic point mutation of p53, which lies outside the activation domain of p53, but reduces its ability to activate transcription, greatly reduced the ability of p53 to bind yeast TBP in vitro. This mutation probably affects the overall conformation of the protein and indirectly interferes with the ability of p53 to contact TBP and activate transcription. In contrast, a mutated oncogenic form of p53 that is unaffected in its ability to activate transcription bound yeast TBP as well as wild type p53. The human TBP activity in a HeLa extract also bound to the activation domain of p53. Our data support a general model in which DNA-bound activator proteins activate transcription by interacting with TBP.

Highlights

From the Banting and Best InstituotfeMedical Research in transfectedcells (8)and usually affect the abilityof p53 to and the Departmentof Molecular and Medical Genetics, bind to DNA(9)
The acidic activation domain of tography to show that the cellular transcription factor, virion protein 16 (VP16) has beenshown to interact directlywith the TATA
A human tumor-derived oncogenic point mutation ofp53, which lies outside the activation box-binding protein, TBP,’a subunit of the RNApolymerase I1 general initiation factor TFIID (11).Mutations in VP16 that compromise its ability to activate transcriptio(1n2) compromise its ability to bind TB(P13)

Summary

Introduction

From the Banting and Best InstituotfeMedical Research in transfectedcells (8)and usually affect the abilityof p53 to and the Departmentof Molecular and Medical Genetics, bind to DNA(9). The TBP-binding region of p53 was activate transcription. Genic form of p53 that is unaffected in its ability to The human TFIID activity in a HeLa cell extract was activate transcriptionbound yeast TBP as well awsild detected binding to this activation domain of p53.

Results

Conclusion