CAREER: Investigating the Role of an RNA Interference Pathway in Safeguarding the Tetrahymena Thermophila Somatic Genome

Western Washington University, Bellingham WA

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Protection of our genomes from mutation and DNA damage is critical for sustaining life and preventing disease. While there are a variety of ways by which cells ensure genome integrity, recent studies have revealed new players in genome protection that consist of RNA molecules and RNA-associated proteins. Yet much remains to be understood about how these biomolecules function. Therefore, the goal of this project is to deepen our understanding of how RNA and RNA-associated proteins ensure the integrity of genomes through investigation of an RNA-based process in a single-celled organism that has long served as the basis of foundational discoveries in biology: Tetrahymena thermophila. The scientific insights afforded by this project are expected to have important implications for how diverse organisms, including humans, use RNA-based processes to protect their genomes and how disruptions to these processes may underlie disease. In addition, this project will provide opportunities to expand access to authentic research experiences and STEM professional development for undergraduate students at four primarily undergraduate institutions in the Northwest – Western Washington University, Heritage University, Pacific University, and Carroll College. The educational aspects of this project are anticipated to promote the retention and success of students in science, thereby strengthening our future scientific workforce. Biological processes as diverse as cell division and differentiation, defense against viruses and transposons, and organismal development depend on RNA interference (RNAi) pathways. While RNAi is best understood as a mechanism that represses gene expression and ensures proper chromatin structure around centromeres, recent studies in diverse eukaryotes have uncovered new roles for RNAi factors in preventing or repairing DNA damage. The details of these new roles and how evolutionarily conserved they are remain to be fully elucidated. This project will investigate the mechanisms and genomic locations for a newly uncovered role for RNAi in maintaining genome integrity in the ciliated model eukaryote Tetrahymena thermophila. This work will leverage established reverse genetic, fluorescence microscopy, and biochemical approaches developed or adapted for use in Tetrahymena. These studies have the potential to reveal both species-specific and broadly conserved mechanisms for RNAi-governed genome integrity, advancing our understanding of emerging roles for RNA in genome protection. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.