In vivo analyses of UV-irradiation-induced p53 promoter binding using a novel quantitative real-time PCR assay
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Published on: January 31, 2018
Jenny C Potratz1, Barbara Mlody, Wolfgang E Berdel
1Department of Medicine, Hematology and Oncology, University of Münster, D-48149 Münster, Germany.
Abstract:
The p53 tumor suppressor protein mediates cell cycle arrest and apoptosis through transactivation of downstream target genes. While many target genes have been identified to date, the mechanisms and time course of their induction are still unclear. We investigated the kinetics of p53 binding to the p21CIP1, MDM2, BAX and PIG3 promoters in vivo using a novel quantitative real-time chromatin immunoprecipitation-PCR assay. Our results demonstrate distinct kinetics of p53 promoter binding dependent on the target gene promoters. The timed induction of target genes due to genotoxic stress is likely to play a pivotal role for the divergent functions of p53.
Insights
This study reveals that the p53 protein binds to different target gene promoters at distinct times after genotoxic stress. Understanding these p53 binding kinetics is crucial for the tumor suppressor
Area of Science:
- Molecular Biology
- Cancer Research
- Cell Biology
Background:
- The p53 protein is a critical tumor suppressor.
- p53 regulates cell cycle arrest and apoptosis.
- Mechanisms and timing of p53 target gene induction are not fully understood.
Purpose of the Study:
- To investigate the kinetics of p53 binding to specific gene promoters in vivo.
- To elucidate the time course of p53-promoter interactions.
- To understand how promoter binding kinetics relate to p53 function.
Main Methods:
- Utilized a quantitative real-time chromatin immunoprecipitation-PCR (ChIP-PCR) assay.
- Monitored p53 binding to p21CIP1, MDM2, BAX, and PIG3 promoters in vivo.
- Analyzed promoter binding kinetics following genotoxic stress.
Main Results:
- Demonstrated distinct kinetics of p53 binding across different target gene promoters.
- Observed varying time courses for p53 engagement with p21CIP1, MDM2, BAX, and PIG3.
- p53 binding kinetics are promoter-specific.
Conclusions:
- The timed induction of p53 target genes is critical for its diverse cellular functions.
- Distinct p53 promoter binding kinetics contribute to the differential regulation of target genes.
- Understanding these kinetics provides insight into p53's role in tumor suppression.
