Broadening prime editing toolkits using RNA-Pol-II-driven engineered pegRNA.

Area of Science:

• Molecular Biology
• Gene Editing Technologies
• Cellular and Genetic Engineering

Background:

• Prime editing (PE) enables precise DNA modifications like point mutations, insertions, and deletions.
• The canonical PE3 system exhibits limitations in efficiency, particularly in primary and pluripotent stem cells.

Purpose of the Study:

• To enhance the efficiency and expand the applications of prime editing.
• To overcome limitations associated with RNA polymerase III (RNA-Pol-III) promoters in PE systems.
• To achieve efficient and accurate genetic editing in human embryonic stem cells.

Main Methods:

• Utilized RNA polymerase II promoters for Csy4-processed intronic prime editing guide RNAs (pegRNAs).
• Implemented optimizations including poly(T)-containing pegRNAs for improved targeting.
• Investigated simultaneous suppression of DNA mismatch repair and DNA damage response pathways.

Main Results:

• Achieved efficient genetic targeting and editing using the modified PE system.
• Enabled combinatorial and conditional genetic editing strategies.
• Demonstrated highly efficient and accurate prime editing in human embryonic stem cells through pathway suppression.

Conclusions:

• The developed system overcomes RNA-Pol-III promoter restrictions, broadening prime editing applications.
• Optimized pegRNA design and promoter choice enhance editing efficiency.
• Suppression of DNA repair pathways is crucial for efficient editing in human stem cells.