Increasing the targeting scope and efficiency of base editing with Proxy-BE strategy

Area of Science:

• Molecular Biology
• Gene Editing Technologies
• Biotechnology

Background:

• Base editors (BEs) are advanced tools for precise gene editing.
• BE efficiency is often limited by obstacles, potentially including the chromatin microenvironment.

Purpose of the Study:

• To develop an improved gene editing strategy, termed Proxy-BE, to enhance base editor efficiency.
• To investigate the role of the chromatin microenvironment in base editing efficiency.

Main Methods:

• Developed Proxy-BE by combining a nuclease-dead Cas9 (dCas9) with established base editors (SaKKH-BE3 and dCpf1-BE).
• dCas9 was targeted to a site near the DNA target to potentially alter the local chromatin structure.
• Evaluated the impact of Proxy-BE on the efficiency of the tested base editors.

Main Results:

• Proxy-BE significantly enhanced the efficiency of both SaKKH-BE3 and dCpf1-BE.
• The strategy effectively doubled the canonical base editing efficiency compared to base editors used alone.
• The findings suggest that altering the DNA accessibility via dCas9 improves the editing microenvironment.

Conclusions:

• Proxy-BE offers a novel and effective approach to enhance base editing efficiency.
• This strategy holds promise for advancing biological research and therapeutic applications of gene editing.
• The development of Proxy-BE addresses key limitations in current base editing technologies.