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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Binding and modulation of p53 by p300/CBP coactivators
N L Lill1, S R Grossman, D Ginsberg
1The Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Nature
|June 19, 1997
Summary
Viral oncoproteins disrupt p53 function by interfering with p300/CBP binding. This interaction is crucial for p53
Area of Science:
- Molecular Biology
- Cell Biology
- Virology
Background:
- Adenovirus E1A and SV40 large-T-antigen oncoproteins interact with p300/CBP transcriptional coactivators.
- This interaction is linked to cellular transformation mechanisms.
- A shared binding region on T antigen suggests a connection between p53 and p300/CBP functions.
Purpose of the Study:
- To investigate the direct interaction between p300/CBP and p53.
- To determine the functional consequences of this interaction on p53-mediated cellular processes.
- To elucidate the role of p300/CBP as a mediator of p53 activity.
Main Methods:
- Co-immunoprecipitation assays to detect protein-protein interactions.
- Immunofluorescence microscopy to assess subcellular localization.
- Reporter gene assays to measure promoter activation.
- Cell cycle analysis and apoptosis assays to evaluate functional outcomes.
Main Results:
- p300/CBP directly binds to p53 in the absence of viral oncoproteins.
- p300 and p53 colocalize in the nucleus and form a stable DNA-binding complex.
- Adenovirus E1A disrupts p53-mediated transcriptional activation of p21 and bax promoters.
- E1A suppresses p53-induced G1 cell-cycle arrest and apoptosis.
Conclusions:
- p300/CBP acts as a transcriptional adaptor for p53.
- p300/CBP modulates p53's role in G1 cell-cycle checkpoint control and apoptosis induction.
- Disruption of the p300/p53 complex by viral oncoproteins contributes to cellular transformation.
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