Prime editing turns tRNAs into universal suppressors for nonsense mutations
Researchers used prime editing to convert a single endogenous tRNA into an optimized suppressor tRNA, enabling permanent readthrough of premature stop codons without overexpression. The PERT strategy restored protein function in multiple human cell models and rescued disease pathology in a mouse model while showing no detected increase in natural stop codon readthrough.
- PERT permanently converts a dispensable endogenous tRNA into an engineered suppressor tRNA using prime editing.
- An iterative screen of thousands of variants across all 418 human tRNAs identified potent suppressor tRNAs, especially for TAG stop codons.
- A single genomic copy of engineered suppressor tRNAs restored 20 to 70 percent of normal enzyme activity in cell models of Batten disease, Tay Sachs disease and cystic fibrosis.
- In mice a single prime editor produced about 25 percent full-length GFP from a reporter and about 6 percent IDUA enzyme activity in a Hurler syndrome model, leading to near complete rescue of disease pathology.
- The reported experiments found no detectable readthrough of natural stop codons and no major transcriptomic or proteomic changes.
- The method is disease agnostic for many premature termination codons but TAA suppression was ineffective and further work on delivery, long term safety and clinical translation is still required.