Steroid receptor coactivator-1 and its family members differentially regulate transactivation by the tumor suppressor protein p53.
The tumor suppressor protein p53 exerts its cell cycle-regulatory effects through its ability to function as a sequence-specific DNA-binding transcription factor. Herein, we show that p53 physically interacts with specific subregions of steroid receptor coactivator-1 (SRC-1) and its family members, p/CIP (p300/CBP interacting protein), xSRC-3, and AIB1 (amplified in breast cancer), originally isolated as transcription coactivators of nuclear receptors, as demonstrated by the yeast and mammalian two-hybrid tests as well as glutathione S-transferase pull-down assays. Interestingly, cotransfection of HeLa cells with SRC-1- or p/CIP expression vector potentiated the p53-mediated transactivation, whereas AIB1 and xSRC-3 were repressive. All of these SRC-1 members, however, similarly stimulated transactivation mediated by nuclear receptors and AP-1, as previously described. These results suggest that SRC-1 and its family members may differentially modulate the p53 transactivation in vivo.
Pubmed ID: 10551785 RIS Download
Acetyltransferases | Bacterial Proteins | HeLa Cells | Histone Acetyltransferases | Humans | Nuclear Receptor Coactivator 1 | Nuclear Receptor Coactivator 3 | Oncogene Proteins | Protein Isoforms | Recombinant Proteins | Serine Endopeptidases | Trans-Activators | Transcription Factors | Transcriptional Activation | Transfection | Tumor Suppressor Protein p53