Both environmental and endogenous processes generate pathologically high levels of ROS, with subsequent damage to lipids, proteins and DNA promoting mutation and cell death. However, low levels of ROS are physiologically important in regulating cell proliferation and gene expression.1,2 Cells must thus prevent the detrimental and promote the beneficial aspects of ROS, which suggests that there are precise regulatory strategies to maintain proper ROS levels. We propose to test the hypothesis that cells manage ROS balance by turning-on and turning-off the translation of ROS detoxification and DNA damage response proteins, using the opposing activities of the RNA methyltransferases ALKBH8 and TRM9L. The underlying mechanism arises from our discovery that enzyme-catalyzed methylation signals by ALKBH8, operating at the level of tRNA modification to anticodons, can translationally up-regulate selenocysteine (Sec)-containing ROS management proteins. These RNA modifications are required for stop-codon recoding - the mechanism of reading internal stop-codons as Sec-codons in mRNAs for Sec-containing glutathione peroxidases (GPXs, antioxidants) and thioredoxin reductases (TrxRs, regulate ribonucleotide reductase activity to promote the DNA damage response). We hypothesize that dueling RNA modifications control stop-codon recoding to promote (ALKBH8) or prevent (TRM9L) the translation of Sec-proteins and thus regulate ROS and DNA damage responses. Further, we hypothesize that part of the process of carcinogenicity involves hijacking of RNA modification systems to turn-off stress responses and promote a pro-mutagenic program of ROS-induced DNA damage and decreased DNA repair. To facilitate our studies, we have developed a modification analysis platform to monitor 33 human tRNA modifications and we have demonstrated that anticodon modifications are significantly regulated in response to ROS stress. Together with our RNA modification analysis platform, we will use biochemical, molecular and computational analyses to test our hypothesis in a robust set of normal, cancer- derived and engineerable lines. Importantly, our studies will define a novel system of translational control of stress response, dissect the mechanism a pro-mutagenic program, and reveal new targets and strategies for cancer treatment and prevention.

Public Health Relevance

Reactive oxygen species (ROS) can damage DNA, promote mutations and cause disease in humans. Cellular ROS detoxification and DNA repair are therefore essential processes for maintaining genome stability and preventing cancer. In this application, we propose to better understand how cells manage ROS by testing a novel hypothesis that cells respond to ROS by modulating opposing RNA modification enzymes to turn-on or turn-off the translation of key ROS-detoxification and DNA damage response proteins. Further, we will define how dysregulation of the RNA modification systems during environmental stresses and pathological conditions can promote DNA damage and carcinogenesis, with our results providing critical information for improving cancer prevention and treatment strategies.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES024615-02
Application #
8911316
Study Section
Cancer Etiology Study Section (CE)
Program Officer
Reinlib, Leslie J
Project Start
2014-08-15
Project End
2016-05-31
Budget Start
2015-06-01
Budget End
2016-05-31
Support Year
2
Fiscal Year
2015
Total Cost
Indirect Cost
Name
State University of New York at Albany
Department
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
152652822
City
Albany
State
NY
Country
United States
Zip Code
12222
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Rothenberg, Daniel A; Taliaferro, J Matthew; Huber, Sabrina M et al. (2018) A Proteomics Approach to Profiling the Temporal Translational Response to Stress and Growth. iScience 9:367-381
Chan, Cheryl; Pham, Phuong; Dedon, Peter C et al. (2018) Lifestyle modifications: coordinating the tRNA epitranscriptome with codon bias to adapt translation during stress responses. Genome Biol 19:228
Idelchik, MarĂ­a Del Pilar Sosa; Begley, Ulrike; Begley, Thomas J et al. (2017) Mitochondrial ROS control of cancer. Semin Cancer Biol 47:57-66
Molinie, Benoit; Wang, Jinkai; Lim, Kok Seong et al. (2016) m(6)A-LAIC-seq reveals the census and complexity of the m(6)A epitranscriptome. Nat Methods 13:692-8
Doyle, Frank; Leonardi, Andrea; Endres, Lauren et al. (2016) Gene- and genome-based analysis of significant codon patterns in yeast, rat and mice genomes with the CUT Codon UTilization tool. Methods 107:98-109
Shen, Lisha; Liang, Zhe; Gu, Xiaofeng et al. (2016) N(6)-Methyladenosine RNA Modification Regulates Shoot Stem Cell Fate in Arabidopsis. Dev Cell 38:186-200
Endres, Lauren; Begley, Ulrike; Clark, Ryan et al. (2015) Alkbh8 Regulates Selenocysteine-Protein Expression to Protect against Reactive Oxygen Species Damage. PLoS One 10:e0131335
Chan, Clement T Y; Deng, Wenjun; Li, Fugen et al. (2015) Highly Predictive Reprogramming of tRNA Modifications Is Linked to Selective Expression of Codon-Biased Genes. Chem Res Toxicol 28:978-88
Deng, Wenjun; Babu, I Ramesh; Su, Dan et al. (2015) Trm9-Catalyzed tRNA Modifications Regulate Global Protein Expression by Codon-Biased Translation. PLoS Genet 11:e1005706

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