TRUB1 is a pseudouridine synthase that catalyzes pseudouridylation of both mRNAs and tRNAs in humans 123. As the major mRNA pseudouridine synthase, TRUB1 recognizes mRNAs with the consensus sequence 5'-GUUCNANNC-3' containing stem-loop structures 12. Quantitative mapping reveals TRUB1 targets exhibit the highest modification stoichiometry among pseudouridine synthases 4. In mitochondria, TRUB1 catalyzes pseudouridine(55) synthesis in a subset of tRNAs (tRNAAsn, tRNAGln, tRNAGlu, tRNAPro), with deficiency impairing mitochondrial translation and oxidative phosphorylation biogenesis 5. Additionally, TRUB1 regulates microRNA maturation independently of its synthase activity by binding pri-let-7 stem-loops and preventing LIN28 binding, thereby enhancing DGCR8-mediated let-7 processing 36. Recent evidence indicates TRUB1-installed pseudouridine sites promote mRNA transcript stabilization 7. TRUB1 and PUS10 exhibit functional redundancy for cytosolic tRNA Ψ55 modification 8. Clinically, low TRUB1 expression correlates with poor glioblastoma prognosis 9.