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Published on: February 7, 2019
Identification of p53 regulators by genome-wide functional analysis
Qihong Huang1, Angel Raya, Paul DeJesus
1Department of Chemistry, The Scripps Research Institute, Mail Stop SR202, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Summary
Researchers identified nine genes that regulate the p53 tumor-suppressor protein. Key transcription factors like HES1 and HEY1 activate p53, impacting cell growth and apoptosis.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- The p53 protein is a crucial tumor suppressor controlling cell cycle arrest and apoptosis.
- Understanding p53 regulation is vital for cancer research and therapeutic development.
Purpose of the Study:
- To identify novel proteins that modulate p53 transcriptional activity.
- To elucidate the mechanisms by which these proteins regulate p53 function.
Main Methods:
- A large-scale gain-of-function cellular screen using an arrayed cDNA library (approx. 20,000 cDNAs).
- Analysis of gene overexpression effects on p53 activity in mammalian cells.
- Investigating the impact of identified factors on HDM2 transcription.
- In vivo studies in zebrafish and avian models, and mouse embryonic fibroblast transformation assays.
Main Results:
- Nine novel genes regulating p53 activity were identified.
- Seven genes (e.g., HEY1, HES1, TFAP4) up-regulated p53 activity, while two (M17S2, cathepsin B) down-regulated it.
- HES1, HEY1, TFAP4, and OSR1 activated p53 by repressing HDM2 transcription.
- Overexpression of these factors induced apoptosis in vivo and abrogated ras/myc-mediated transformation in a p53-dependent manner.
Conclusions:
- Identified transcription factors are part of an evolutionarily conserved network regulating p53.
- These factors represent potential targets for cancer therapy by modulating p53 pathway.
- The findings provide new insights into the complex regulation of the p53 tumor suppressor.
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