A series of precise and controllable base editors with split-TadA-8e

Area of Science:

• Molecular Biology
• Gene Editing Technologies
• Biotechnology

Background:

• Adenine base editors (ABEs) are crucial for A-to-G DNA conversions in research and medicine.
• ABE8e, based on TadA-8e, is widely used but has safety concerns due to off-target mutations.
• Existing fusion-based editors like AYBE and eA&C-BEmax also face similar challenges.

Purpose of the Study:

• To develop a controllable adenine base editor with reduced off-target effects.
• To engineer split versions of ABE8e and its derivatives (AYBE, eA&C-BEmax) for enhanced safety and precision.
• To assess the on-target activity and off-target profile of the novel split base editors.

Main Methods:

• Splitting the TadA-8e component of ABE8e to create a rapamycin-inducible system (sABE8e).
• Developing split versions of AYBE (sAYBE) and eA&C-BEmax (seA&C-BEmax) using the split TadA-8e strategy.
• Evaluating on-target editing efficiency and off-target effects (DNA and RNA) of the engineered base editors.

Main Results:

• sABE8e demonstrated comparable on-target adenine editing activity to ABE8e.
• sABE8e exhibited significantly reduced DNA and RNA off-target effects compared to ABE8e.
• The controllable sAYBE and seA&C-BEmax showed similar or slightly lower editing efficiency but with decreased off-target mutations.

Conclusions:

• Split adenine base editors offer a precise and controllable alternative to existing ABEs.
• The developed sABE8e, sAYBE, and seA&C-BEmax enhance safety by minimizing off-target edits.
• These novel tools hold promise for advancing gene editing applications in basic research and clinical settings.