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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Stimulus-specific transcriptional regulation within the p53 network
Aaron Joseph Donner1, Jennifer Michelle Hoover, Stephanie Aspen Szostek
1Department of Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado, USA.
Cell Cycle (Georgetown, Tex.)
|October 25, 2007
Summary
The p53 protein
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- The p53 protein network regulates stress responses, including cell cycle arrest and apoptosis.
- Differential activation of p53 target genes is crucial for stress-specific outcomes but remains unclear.
- Understanding these mechanisms is vital for cancer therapy development.
Purpose of the Study:
- To investigate how distinct p53 target genes are differentially activated by various stimuli.
- To elucidate the role of transcriptional coregulators in mediating stimulus-specific p53 target gene expression.
- To analyze the p53 transcriptional program in response to DNA damage (UVC, doxorubicin) and non-genotoxic activation (Nutlin-3).
Main Methods:
- Quantitative gene expression analysis to classify p53 target genes.
- Chromatin immunoprecipitation (ChIP) to analyze p53 binding and histone acetylation at the p21 locus.
- Investigation of the human Mediator complex's role in p21 transcription.
Main Results:
- p53 target genes were grouped into three classes based on activation profiles under different stress conditions.
- The cyclin-dependent kinase inhibitor p21 (CDK-inhibitor p21) was activated during cell cycle arrest but not UVC-induced apoptosis.
- Stimulus-specific coregulators, particularly the Mediator complex CDK-module, modulate p53-dependent p21 transcription.
Conclusions:
- The Mediator complex CDK-module acts as a stimulus-specific positive coregulator for p53 target genes like p21.
- Differential gene activation within the p53 network is controlled by downstream coregulators, enabling distinct cellular responses.
- This provides insight into the precise control of stress responses mediated by the p53 network.
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