Transcriptome-wide Analysis of Roles for tRNA Modifications in Translational Regulation.

Covalent nucleotide modifications in noncoding RNAs affect a plethora of biological processes, and new functions continue to be discovered even for well-known modifying enzymes. To systematically compare the functions of a large set of noncoding RNA modifications in gene regulation, we carried out ribosome profiling in budding yeast to characterize 57 nonessential genes involved in tRNA modification. Deletion mutants exhibited a range of translational phenotypes, with enzymes known to modify anticodons, or non-tRNA substrates such as rRNA, exhibiting the most dramatic translational perturbations. Our data build on prior reports documenting translational upregulation of the nutrient-responsive transcription factor Gcn4 in response to numerous tRNA perturbations, and identify many additional translationally regulated mRNAs throughout the yeast genome. Our data also uncover unexpected roles for tRNA-modifying enzymes in regulation of TY retroelements, and in rRNA 2'-O-methylation. This dataset should provide a rich resource for discovery of additional links between tRNA modifications and gene regulation.