Poster abstracts

Poster number 119 submitted by Ernesto Roldan-Bonet

Genome-wide application of a tRNA assay to uncover proteins involved in the tRNA retrograde pathway

Ernesto J. Roldan-Bonet (Department of Molecular Genetics, The Ohio State University), Paolo L. Sinopoli (Department of Molecular Genetics, The Ohio State University), Anita K. Hopper (Department of Molecular Genetics, The Ohio State University)

Abstract:
Transfer RNAs(tRNAs) are initially transcribed in the nucleus and subsequently transported to the cytoplasm where they function as essential adaptor molecules in translation. Given their cytoplasmic function, tRNA subcellular trafficking was thought to be unidirectional – from the nucleus to the cytoplasm. It is now well documented that tRNAs are shuttled back into the nucleus via the tRNA retrograde nuclear import step before re-localizing to the cytoplasm via tRNA nuclear re-export. These latter two subcellular trafficking steps have been implicated in several important functions. Substantial progress has been made in the identification of the proteins involved in tRNA nuclear re-export, yet the proteins involved in tRNA retrograde nuclear import are largely unknown. We recently developed, and validated, an assay in Saccharomyces cerevisiae to identify proteins involved in the tRNA nuclear retrograde pathway of tRNAPhe, taking advantage of the post-transcriptional modification wybutosine (yW). Now, we are employing this assay at a genome-wide level. We optimized the procedures and have screened over 400 gene deletion mutants. So far, we have unbiasedly identified Tyw2, a protein normally required for yW synthesis – validating our approach. Taken together, our study aims to further the understanding of proteins involved in the tRNA nuclear retrograde pathway – a widely conserved process.

References:
Chatterjee, K., Marshall, W. A., & Hopper, A. K. (2022). Three tRNA nuclear exporters in S. cerevisiae: parallel pathways, preferences, and precision. Nucleic Acids Research, 50(17), 10140–10152. https://doi.org/10.1093/nar/gkac754

Nostramo, R. T., & Hopper, A. K. (2020). A novel assay provides insight into tRNAPhe retrograde nuclear import and re-export in S. Cerevisiae. Nucleic Acids Research, 48(20), 11577–11588. https://doi.org/10.1093/nar/gkaa879

Keywords: wybutosine, tRNA retrograde pathway, subcellular trafficking