Improved USER cloning for TALE assembly and its application to base editing

Area of Science:

• Molecular Biology
• Gene Editing Technologies
• Synthetic Biology

Background:

• Transcription activator-like effectors (TALEs) are versatile tools for genome editing, transcriptional regulation, and DNA imaging.
• Traditional TALE construction is complex and time-consuming, limiting their routine laboratory use.

Purpose of the Study:

• To develop a simple, rapid, and laboratory-friendly method for TALE assembly.
• To create efficient base editing systems using the improved TALE construction technique.

Main Methods:

• Utilized uracil-specific excision reagent (USER) cloning for TALE assembly.
• Employed polymerase chain reaction with TALE trimer templates and deoxyuridine-containing primers.
• Hierarchically rejoined TALE trimer units using USER and T4 DNA Ligase for high-efficiency vector construction.

Main Results:

• Successfully constructed TALE-deaminases using the USER assembly method.
• Demonstrated efficient C-to-T and A-to-G base editing when TALE-deaminases were combined with Cas9 nickases.
• Eliminated predictable DNA off-target effects in base editing applications.

Conclusions:

• The improved USER assembly is a highly efficient and rapid technique for TALE construction.
• This method simplifies TALE-based genome engineering and base editing.
• The technique offers a valuable, laboratory-friendly approach for DNA targeting applications.