Poster abstracts
Poster number 33 submitted by Sophie Cihan
Binding Preferences amongst Three Saccharomyces cerevisiae tRNA Primary Nuclear Exportins
Sophie Cihan (Department of Molecular Genetics, The Ohio State University), Jackson Hastings (Department of Molecular Genetics, The Ohio State University), Anita K. Hopper (Department of Molecular Genetics, The Ohio State University)
Abstract:
tRNAs are diverse, highly modified molecules. Disruptions in tRNA biogenesis are linked to human diseases, including neuronal disorders, neurodegenerative disorders, and cancer. tRNAs must be trafficked out of the nucleus to perform their iterative function in the cytoplasm by a pathway termed primary nuclear export. There are 42 tRNA gene families in Saccharomyces cerevisiae, 10 of which contain introns which are spliced in the cytoplasm. Primary tRNA nuclear export employs at least three nuclear exportins: Los1, Mex67-Mtr2, and Crm1. However, the binding preferences these three exportins have for different intron-containing tRNAs is not understood.
We aim to uncover new insights regarding pre-tRNA and nuclear exportin preferences in primary nuclear export. Two approaches offer different perspectives into this pathway. First, we are currently purifying intron-containing pre-tRNAs via pulldowns using biotinylated oligonucleotides complementary to their introns. The relative abundances of co-purifying exporters will be identified via Mass Spectrometry. To ensure the specificity of the methods, biotinylated tRNA pulldowns were optimized using purified small RNA preparations. Second, we utilized qRT-PCR to measure relative abundances of intron-containing tRNAs between Wild-Type and los1∆ strains. A given tRNA’s dependence on Los1 for export can then be inferred by the relative difference between that tRNA’s abundance in los1∆ compared to Wild-Type strains.
References:
1. Phizicky EM, Hopper AK. The life and times of a tRNA. RNA. 2023 Jul;29(7):898-957.
2. Huang HY, Hopper AK. Multiple Layers of Stress-Induced Regulation in tRNA Biology. Life (Basel). 2016 Mar 23;6(2):16.
3. Chatterjee K, Nostramo RT, Wan Y, Hopper AK. tRNA dynamics between the nucleus, cytoplasm and mitochondrial surface: Location, location, location. Biochim Biophys Acta Gene Regul Mech. 2018 Apr;1861(4):373-386.
4. Chatterjee K, Marshall WA, Hopper AK. Three tRNA nuclear exporters in S. cerevisiae: parallel pathways, preferences, and precision. Nucleic Acids Res. 2022 Sep 23;50(17):10140-10152.
Keywords: tRNA, nuclear trafficking, S cerevisiae