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TAp73 contributes to the oxidative stress response by regulating protein synthesis.

Published version
Peer-reviewed

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Authors

Marini, A 
Rotblat, B 
Sbarrato, T 
Niklison-Chirou, MV 
Knight, JRP 

Abstract

TAp73 is a transcription factor that plays key roles in brain development, aging, and cancer. At the cellular level, TAp73 is a critical homeostasis-maintaining factor, particularly following oxidative stress. Although major studies focused on TAp73 transcriptional activities have indicated a contribution of TAp73 to cellular metabolism, the mechanisms underlying its role in redox homeostasis have not been completely elucidated. Here we show that TAp73 contributes to the oxidative stress response by participating in the control of protein synthesis. Regulation of mRNA translation occupies a central position in cellular homeostasis during the stress response, often by reducing global rates of protein synthesis and promoting translation of specific mRNAs. TAp73 depletion results in aberrant ribosomal RNA (rRNA) processing and impaired protein synthesis. In particular, polysomal profiles show that TAp73 promotes the integration of mRNAs that encode rRNA-processing factors in polysomes, supporting their translation. Concurrently, TAp73 depletion causes increased sensitivity to oxidative stress that correlates with reduced ATP levels, hyperactivation of AMPK, and translational defects. TAp73 is important for maintaining active translation of mitochondrial transcripts in response to oxidative stress, thus promoting mitochondrial activity. Our results indicate that TAp73 contributes to redox homeostasis by affecting the translational machinery, facilitating the translation of specific mitochondrial transcripts. This study identifies a mechanism by which TAp73 contributes to the oxidative stress response and describes a completely unexpected role for TAp73 in regulating protein synthesis.

Description

Keywords

ROS, TAp73, mitochondria, p53 family, translation, A549 Cells, HEK293 Cells, Humans, Mitochondria, Oxidative Stress, Protein Biosynthesis, Reactive Oxygen Species, TOR Serine-Threonine Kinases, Tumor Protein p73

Journal Title

Proc Natl Acad Sci U S A

Conference Name

Journal ISSN

0027-8424
1091-6490

Volume Title

115

Publisher

Proceedings of the National Academy of Sciences
Sponsorship
MRC (TOX GRA 06 02 013)
Wellcome Trust (201847/Z/16/Z)