PseudoUridine (Ψ) is a tautomer of uridine. Among the many known RNA chemical modifications, Ψ is a common modification with high abundance. Ψ is widely found in mRNA, tRNA, rRNA and snRNA.
Formation of PseudoUridine in RNA
- The mechanism depends only on proteins, i.e., pseudoUridine synthases or PUS. (Exist in eukaryotes and prokaryotes)
- Depends on a complex formed by snRNA (a class of H/ACA box small ribonucleic acid) and the corresponding protein. (Exist only in eukaryotes)
Function of PseudoUridine
- Ψ modifications in rRNA are ubiquitous in large and small subunits of human RNA and are mainly clustered and distributed in functionally important regions, and may affect the folding of rRNA, the assembly of ribosomes, and the maintenance of corresponding higher structures.
- Ψ modifications in snRNA act mainly through the interaction between RNA and RNA during splicing.
- The introduction of Ψ modification in the stop codon can turn the stop codon into a sense codon, which changes the gene coding function. When the in vitro transcribed mRNA containing Ψ modification was injected into the body, the translation rate and stability of the modified RNA were increased compared with the mRNA without Ψ modification.
Application of pseudoUridine
- R&D and production of drugs
- mRNA vaccine
- Clinical disease diagnostic testing