Cao Xiaofang, Guo Junfan, Huang Shisheng, Yu Wenxia, Li Guanglei, An Lisha, Li Xiangyang, Tao Wanyu, Liu Qing, Huang Xingxu, Jin Xiaohua, Ma Xu
National Research Institute for Family Planning, Beijing 100081, China.
Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China.
Mol Ther Nucleic Acids. 2022 May 4;28:732-742. doi: 10.1016/j.omtn.2022.04.032. eCollection 2022 Jun 14.
About 47% of pathogenic point mutations could be corrected by ABE-induced A·T-to-G·C conversions. However, the applications of ABEs are still hindered by undesired editing efficiency, limited editing scopes, and off-targeting effects. Here, we develop a new adenine base editor, by embedding TadA-8e monomer into SpRY-nCas9, named as CE-8e-SpRY, which exhibits higher activity at NRN than NYN PAMs favored by SpRY nuclease. CE-8e-SpRY could target nearly all genomic sites in principle and induces the highest targeting efficiency among tested SpRY-based ABEs. In addition, CE-8e-SpRY also shows reduced RNA and DNA off-targeting activities. With optimized sgRNAs, CE-8e-SpRY induces efficient or desired target editing at some disease-relevant loci where conventional ABEs were unable to induce precise and satisfied editing. Taken together, our CE-8e-SpRY could broaden the applicability of ABEs in correcting or introducing pathogenic point mutations.
约47%的致病性点突变可通过ABE诱导的A·T到G·C转换得到纠正。然而，ABE的应用仍然受到不理想的编辑效率、有限的编辑范围和脱靶效应的阻碍。在此，我们通过将TadA-8e单体嵌入SpRY-nCas9中开发了一种新的腺嘌呤碱基编辑器，命名为CE-8e-SpRY，它在NRN处比SpRY核酸酶青睐的NYN PAMs表现出更高的活性。CE-8e-SpRY原则上可以靶向几乎所有基因组位点，并且在测试的基于SpRY的ABE中诱导出最高的靶向效率。此外，CE-8e-SpRY还表现出降低的RNA和DNA脱靶活性。通过优化的sgRNA，CE-8e-SpRY在一些传统ABE无法诱导精确和满意编辑的与疾病相关的位点上诱导了高效或理想的靶标编辑。综上所述，我们的CE-8e-SpRY可以拓宽ABE在纠正或引入致病性点突变方面的适用性。
