Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Nat Commun. 2023 Mar 3;14(1):1224. doi: 10.1038/s41467-023-36887-1.
Base editors, including dual base editors, are innovative techniques for efficient base conversions in genomic DNA. However, the low efficiency of A-to-G base conversion at positions proximal to the protospacer adjacent motif (PAM) and the A/C simultaneous conversion of the dual base editor hinder their broad applications. In this study, through fusion of ABE8e with Rad51 DNA-binding domain, we generate a hyperactive ABE (hyABE) which offers improved A-to-G editing efficiency at the region (A-A) proximal to the PAM, with 1.2- to 7-fold improvement compared to ABE8e. Similarly, we develop optimized dual base editors (eA&C-BEmax and hyA&C-BEmax) with markedly improved simultaneous A/C conversion efficiency (1.2-fold and 1.5-fold improvement, respectively) compared to A&C-BEmax in human cells. Moreover, these optimized base editors catalyze efficiently nucleotide conversions in zebrafish embryos to mirror human syndrome or in human cells to potentially treat genetic diseases, indicating their great potential in broad applications for disease modeling and gene therapy.
碱基编辑器，包括双碱基编辑器，是在基因组 DNA 中进行高效碱基转换的创新技术。然而，在接近前导序列邻近基序 (PAM) 的位置处 A 到 G 的碱基转换效率低，以及双碱基编辑器中 A/C 的同时转换，阻碍了它们的广泛应用。在这项研究中，我们通过将 ABE8e 与 Rad51 DNA 结合结构域融合，生成了一种超活的 ABE（hyABE），它在靠近 PAM 的区域（A-A）提供了改进的 A 到 G 的编辑效率，与 ABE8e 相比提高了 1.2-7 倍。同样，我们开发了优化的双碱基编辑器（eA&C-BEmax 和 hyA&C-BEmax），与 A&C-BEmax 相比，在人类细胞中同时 A/C 转换效率显著提高（分别提高了 1.2 倍和 1.5 倍）。此外，这些优化的碱基编辑器能够在斑马鱼胚胎中有效地催化核苷酸转换，以模拟人类综合征，或在人类细胞中潜在地治疗遗传疾病，表明它们在疾病建模和基因治疗的广泛应用中具有巨大的潜力。
