Expanding the understanding of tRNA lifecycle under cellular stress - Project Summary/Abstract Cellular stress response is a complex and cascading mechanism that affects a multitude of cellular functions aiming on cell survival. Recent studies from the perspective of cellular stress response have expanded our understanding of tRNA to be a diverse and multifunctional molecule. tRNA has been linked to cellular stress response through specific cleavage in the form of tRNA halves (tRNA-derived stress-induced RNAs, or tiRNAs) or smaller tRNA fragments. These tRNA-derived RNAs are commonly found in certain diseases, suggesting their potential importance in disease progression. However, the function and regulation of these alternative tRNA derivatives are not well understood. We hypothesize that tRNA cleavage is regulated by differential RNA modification, and that tiRNAs act as signaling molecules to healthy cells. In the first aim of this study, we will investigate how covalent modifications found in tRNA affect tiRNA synthesis by the RNase angiogenin. We will determine this by two means: the first by directly measuring modifications in cleaved and uncleaved species using mass spectrometry, and the second by looking at tiRNA-protein assosication in the presence and absence of specific modifications. In the second aim of this study, we will test functionality of tiRNA by studying its longevity inside and outside the cell, as well as probe the hypothesis that healthy neighboring cells respond to exported tiRNA. This project will expand our understanding of the roles of tRNA in cellular stress, as well as provide a more detailed information of the tRNA interactome and stress-modulated changes in life cycle. Because of the role that tRNA plays in a multitude of cellular processes, expanding our knowledge of tRNA life cycle has broad implications in the fields of RNA biology, cancer biology, and possibly early disease diagnostics. This grant will provide not just the opportunity for research, but also a foundation in molecular biology techniques. It will also allow me to pursue a new and developing field of research, different from my previous trainings, better preparing me for a future as a PI. This research will take place at Brigham and Women’s Hospital in an open lab space conducive to exchange of ideas and collaboration. Brigham and Women’s provides access to state-of- the-art resources and equipment to complete this research.
