The impact of psuedouridine modification on human tRNA.

Transfer RNA (tRNA) is an important RNA in cells that decodes messenger RNA (mRNA) codons during protein translation to ensure correct amino acid sequences. The biogenesis of tRNA involves multiple processing steps to produce mature and functional molecules. Pseudouridine (Ψ), a derivative of uridine, is an abundant RNA modification and occurs at multiple positions within tRNAs. These modified sites are highly conserved across organisms. Classical biochemical studies have established that Ψ stabilises RNA-RNA interactions, but structural characterisations and molecular dynamics simulations reveal that Ψ can locally remodel tRNA architecture in ways that are dictated by where it is within tRNAs. Advances in transcriptome-wide Ψ mapping have uncovered additional modified sites beyond those previously described, with several novel sites appearing to be regulated in a cellular context-dependent manner. Furthermore, dysregulated pseudouridylation has been implicated in conditions ranging from cancer to inherited genetic disorders. Together, these developments reframe our understanding of Ψ from a well-established RNA stabiliser to a modification with roles far more dynamic, context-dependent, and clinically relevant than previously appreciated. The present review summarises and discusses the up-to-date developments in the impacts of pseudouridylation on human tRNA biogenesis, tRNA functions, and human health. More mechanistic questions remain open and will require further investigation. As pseudouridylation can also happen in mRNA and rRNA, exploring the interplay between these RNAs will be crucial for fundamental biology and advancing Ψ applications in biotechnology and biomedical uses.