Oxidative Stress, Transfer RNA Metabolism, and Protein Synthesis

Oxidative stress refers to excessive intracellular levels of reactive oxygen species (ROS) due to an imbalance between ROS production and the antioxidant defense system. Under oxidative stress conditions, cells trigger various stress response pathways to protect themselves, among which repression of messenger RNA (mRNA) translation is one of the key hallmarks promoting cell survival. This regulation process minimizes cellular energy consumption, enabling cells to survive in adverse conditions and to promote recovery from stress-induced damage. Recent studies suggest that transfer RNAs (tRNAs) play important roles in regulating translation as a part of stress response under adverse conditions. In particular, research relying on high-throughput techniques such as next-generation sequencing and mass spectrometry approaches has given us detailed information on mechanisms such as individual tRNA dynamics and crosstalk among post-transcriptional modifications. Oxidative stress leads to dynamic tRNA changes, including their localization, cleavage, and alteration of expression profiles and modification patterns. Growing evidence suggests that these changes not only are tightly regulated by stress response mechanisms, but also can directly fine-tune the translation efficiency, which contributes to cell- or tissue-specific response to oxidative stress. In this review, we describe recent advances in the understanding of the dynamic changes of tRNAs caused by oxidative stress. We also highlight the emerging roles of tRNAs in translation regulation under the condition of oxidative stress. In addition, we discuss future perspectives in this research field. Antioxid. Redox Signal. 40, 715-735.