Ionizing Radiation and Translation Control: A Link to Radiation Hormesis?

Usha Kabilan,Tyson E Graber,Tommy Alain,Dmitry Klokov

doi:10.3390/ijms21186650

Abstract

Protein synthesis, or mRNA translation, is one of the most energy-consuming functions in cells. Translation of mRNA into proteins is thus highly regulated by and integrated with upstream and downstream signaling pathways, dependent on various transacting proteins and cis-acting elements within the substrate mRNAs. Under conditions of stress, such as exposure to ionizing radiation, regulatory mechanisms reprogram protein synthesis to translate mRNAs encoding proteins that ensure proper cellular responses. Interestingly, beneficial responses to low-dose radiation exposure, known as radiation hormesis, have been described in several models, but the molecular mechanisms behind this phenomenon are largely unknown. In this review, we explore how differences in cellular responses to high- vs. low-dose ionizing radiation are realized through the modulation of molecular pathways with a particular emphasis on the regulation of mRNA translation control.

Highlights

Ionizing radiation (IR) is ubiquitous in the Universe and on Earth and is able to elicit biological response due to the ionization of molecules in the cell
Nonconcordant transcriptional and translational profiles of cells exposed to IR suggest that translation control acts as a gatekeeper, ensuring homeostatic plasticity in the synthesis of a protein repertoire that is essential for a proper cellular response
Mild stress incurred by low-dose IR (LDR), typically encountered environmentally, occupationally or during medical diagnostic procedures, is likely to trigger these protective mechanisms, leading to biological benefits, called radiation hormesis

Summary

Introduction

Ionizing radiation (IR) is ubiquitous in the Universe and on Earth and is able to elicit biological response due to the ionization of molecules in the cell. A person receives an annualized average of 2.4 mSv from various sources, including background radiation [4]. This falls into the range of low-dose IR (LDR) defined as

Radiation Hormesis and Dose-Response Considerations

Radiation Adaptive Responses

Translation Control in Response to LDR

Summary and Future Perspectives