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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Wild-type p53 activates transcription in vitro.
G Farmer1, J Bargonetti, H Zhu
1Department of Biological Sciences, Columbia University, New York 10027.
Nature
|July 2, 1992
Summary
Wild-type p53 protein directly activates transcription in vitro, a function crucial for regulating cell growth. Mutant p53 proteins and SV40 large T antigen can inhibit this transcriptional activation.
Area of Science:
- Molecular Biology
- Cancer Research
- Biochemistry
Background:
- The p53 protein is a critical factor in human cancer, known for its role in regulating cell growth.
- p53 is a sequence-specific DNA-binding protein with a potent activation domain, but its direct role in transcription regulation was unconfirmed.
Purpose of the Study:
- To investigate whether wild-type p53 protein directly regulates transcription.
- To determine the effect of tumor-derived mutant p53 proteins and simian virus 40 large T antigen on p53's transcriptional activity.
Main Methods:
- In vitro transcription assays using purified wild-type and mutant human/murine p53 proteins.
- Analysis of p53 binding to DNA templates containing p53-binding sequences.
- Assessment of inhibition by mutant p53 and SV40 large T antigen.
Main Results:
- Intact purified wild-type p53 proteins strongly activated transcription in vitro.
- Transcriptional activation by p53 was dependent on its ability to bind to a specific DNA sequence.
- Tumor-derived mutant p53 proteins failed to activate transcription and inhibited wild-type p53 activity.
- Simian virus 40 large T antigen inhibited wild-type p53-mediated transcriptional activation.
Conclusions:
- Wild-type p53 directly activates transcription, supporting its role as a transcriptional regulator.
- Mutant p53 proteins and SV40 large T antigen can inhibit p53's transcriptional activity through direct interaction.
- These findings elucidate mechanisms of p53 regulation and its disruption in cancer and viral infections.
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