Prime editing (PE) is a versatile and precise genome editing technique; however, its broad application has been limited by variable efficiency and specificity, often requiring extensive optimization for each target. To overcome some of these limitations, we developed proPE (prime editing with prolonged editing window), a PE tool that employs two sgRNA; one to introduce the nick and another non-cleaving sgRNA to position the reverse transcriptase template in close vicinity of the nick.
ProPE demonstrates significantly improved performance, particularly in editing contexts where standard PE is inefficient. For 76 editings where PE achieves less than 5% efficiency, proPE enhances efficiency up to 29.3% and improves both efficiency and specificity by 6.0 and 3.8-fold, respectively. By addressing key limitations of PE, proPE expands the range of targetable edits, including many pathogenic SNPs.
By extending the editing window and reducing the off-target effect, proPE offers a powerful tool for therapeutic applications.