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14:57
Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Directed evolution of p53 variants with altered DNA-binding specificities by in vitro compartmentalization
Chen Xue Fen1, David W Coomber, David P Lane
1Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore, 138673.
Journal of Molecular Biology
|July 6, 2007
Summary
Researchers evolved p53 tumor suppressor variants with enhanced DNA binding. These variants show altered gene transactivation, impacting cell fate decisions and highlighting the complexity of p53-mediated responses.
Area of Science:
- Molecular Biology
- Cancer Research
- Genetics
Background:
- The p53 tumor suppressor protein plays a critical role in regulating cell fate by controlling the expression of various target genes.
- Understanding how p53 discriminates between different target gene promoters is crucial for deciphering its tumor-suppressive functions.
Purpose of the Study:
- To evolve p53 variants with altered DNA-binding affinities for specific response elements.
- To investigate the functional consequences of these evolved p53 variants on gene transactivation and cellular outcomes.
Main Methods:
- Utilized in vitro compartmentalization (IVC) to evolve p53 variants with enhanced binding to p21 and PUMA gene promoter response elements.
- Analyzed mutations in the L1 loop of the p53 DNA binding domain and the N-terminal proline-rich domain.
- Assessed transactivation activity using reporter gene assays and measured endogenous p21 up-regulation.
Main Results:
- Evolved p53 variants exhibited increased binding affinity for both distal p21 and low-affinity PUMA BS1 response elements.
- These variants demonstrated enhanced transactivation of target promoters and increased up-regulation of endogenous p21 compared to wild-type p53.
- A variant selected for dual response element binding showed increased apoptotic function, suggesting complex phenotypic outcomes.
Conclusions:
- p53 variants with altered DNA-binding properties can be generated using IVC, leading to differential gene transactivation.
- The study underscores that predicting p53's phenotypic outcome based on single-gene transcriptional activation is challenging due to the intricate network of its response.
- These findings provide insights into p53's regulatory mechanisms and their implications for cancer biology.
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