Wang Jinxin, He Qingjing, Zeng Yuqiang, Wu Youming, Wang Mufeng, Xu Wenqing, Wang Zhizhi, Zhang Xiaohui
State Key Laboratory of Common Mechanisms Research for Major Diseases, Suzhou Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Suzhou 215123, China.
School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Mol Ther Nucleic Acids. 2025 Aug 12;36(3):102672. doi: 10.1016/j.omtn.2025.102672. eCollection 2025 Sep 9.
Adenine base editors (ABEs) enable efficient A-to-G base conversions in genomic DNA, serving as powerful tools for basic research and clinical disease treatment. TadA-8e with high processive and compatibility makes ABE8e to be the most widely used adenine base editor and has also facilitated the creation of more elegant base editors based on TadA-8e fusion, such as AYBE and eA&C-BEmax. However, ABE8e has more off-target events including DNA off-target and RNA off-target, which raises safety concerns for precision gene editing. Here, we split the TadA-8e of ABE8e (sABE8e) to enable controlled adenine base editing through rapamycin-induced dimerization between FRB and FKBP12. sABE8e has comparable on-target adenine editing activity to ABE8e while maintaining reduced DNA and RNA off-target effects. Harnessing this site of split TadA-8e, we have also developed controllable AYBE (sAYBE) and eA&C-BEmax (seA&C-BEmax), which both offer similar or slightly low base editing efficiency with decreased off-targets compared to AYBE or eA&C-BEmax. These precise and controllable base editing tools will advance the future application of base editors in basic research and clinical disease treatment.
腺嘌呤碱基编辑器（ABEs）能够在基因组DNA中实现高效的A到G碱基转换，是基础研究和临床疾病治疗的强大工具。具有高持续性和兼容性的TadA-8e使ABE8e成为使用最广泛的腺嘌呤碱基编辑器，也促进了基于TadA-8e融合的更优化碱基编辑器的创建，如AYBE和eA&C-BEmax。然而，ABE8e存在更多的脱靶事件，包括DNA脱靶和RNA脱靶，这引发了对精确基因编辑安全性的担忧。在此，我们拆分了ABE8e的TadA-8e（sABE8e），通过雷帕霉素诱导的FRB和FKBP12之间的二聚化实现可控的腺嘌呤碱基编辑。sABE8e具有与ABE8e相当的靶向腺嘌呤编辑活性，同时减少了DNA和RNA脱靶效应。利用这种拆分的TadA-8e位点，我们还开发了可控的AYBE（sAYBE）和eA&C-BEmax（seA&C-BEmax），与AYBE或eA&C-BEmax相比，它们都具有相似或略低的碱基编辑效率，且脱靶效应降低。这些精确且可控的碱基编辑工具将推动碱基编辑器在基础研究和临床疾病治疗中的未来应用。
