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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Modulation of microRNA processing by p53
Hiroshi I Suzuki1, Kaoru Yamagata, Koichi Sugimoto
1Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Nature
|July 24, 2009
Summary
The tumor suppressor p53 enhances microRNA (miRNA) maturation after DNA damage by interacting with the Drosha complex. This reveals a new role for p53 in regulating miRNA biogenesis and tumor suppression.
Area of Science:
- Molecular Biology
- Cancer Biology
- RNA Biology
Background:
- MicroRNAs (miRNAs) are crucial post-transcriptional gene regulators with roles in both promoting and suppressing tumors.
- Downregulation of miRNAs is common in human cancers, highlighting their tumor-suppressive significance.
- The interplay between tumor suppressor networks and miRNA biogenesis machinery is not fully understood.
Purpose of the Study:
- To investigate the connection between the tumor suppressor p53 and miRNA biogenesis.
- To determine if p53 influences the processing of specific tumor-suppressive miRNAs.
- To elucidate the mechanism by which p53 affects miRNA maturation.
Main Methods:
- Studied the effect of p53 on miRNA processing in HCT116 cells and human diploid fibroblasts.
- Investigated the interaction between p53, the Drosha complex, and DEAD-box RNA helicase p68 (DDX5).
- Utilized transcriptionally inactive p53 mutants to assess the impact on miRNA processing.
Main Results:
- p53 enhances the post-transcriptional maturation of growth-suppressive miRNAs (e.g., miR-16-1, miR-143, miR-145) in response to DNA damage.
- p53 associates with the Drosha processing complex via p68 (DDX5), facilitating primary miRNA to precursor miRNA processing.
- Inactive p53 mutants disrupt the p53-p68-Drosha complex assembly, impairing miRNA processing.
Conclusions:
- p53 plays a transcription-independent role in modulating miRNA biogenesis, integral to its tumor suppressive function.
- This newly identified function of p53 in miRNA processing offers insights into cancer biology.
- p53's regulation of miRNA maturation represents a critical link between cellular stress response and tumor suppression.
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