Evolved cytidine and adenine base editors with high precision and minimized off-target activity by a continuous directed evolution system in mammalian cells
Na Zhao, Jian Zhou, Tianfu Tao, Qi Wang, Jie Tang, Dengluan Li, Shixue Gou, Zhihong Guan, Joshua Seun Olajide, Jiejing Lin, Shuo Wang, Xiaoping Li, Jiankui Zhou, Zongliang Gao, Gang Wang
{"title":"Evolved cytidine and adenine base editors with high precision and minimized off-target activity by a continuous directed evolution system in mammalian cells","authors":"Na Zhao, Jian Zhou, Tianfu Tao, Qi Wang, Jie Tang, Dengluan Li, Shixue Gou, Zhihong Guan, Joshua Seun Olajide, Jiejing Lin, Shuo Wang, Xiaoping Li, Jiankui Zhou, Zongliang Gao, Gang Wang","doi":"10.1038/s41467-024-52483-3","DOIUrl":null,"url":null,"abstract":"<p>Continuous directed evolution of base editors (BEs) has been successful in bacteria cells, but not yet in mammalian cells. Here, we report the development of a Continuous Directed Evolution system in Mammalian cells (CDEM). CDEM enables the BE evolution in a full-length manner with Cas9 nickase. We harness CDEM to evolve the deaminases of cytosine base editor BE3 and adenine base editors, ABEmax and ABE8e. The evolved cytidine deaminase variants on BE4 architecture show not only narrowed editing windows, but also higher editing purity and low off-target activity without a trade-off in on-targeting activity. The evolved ABEmax and ABE8e variants exhibit narrowed or shifted editing windows to different extents, and lower off-target effects. The results illustrate that CDEM is a simple but powerful approach to continuously evolve BEs without size restriction in the mammalian environment, which is advantageous over continuous directed evolution system in bacteria cells.</p>","PeriodicalId":19066,"journal":{"name":"Nature Communications","volume":null,"pages":null},"PeriodicalIF":14.7000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature Communications","FirstCategoryId":"103","ListUrlMain":"https://doi.org/10.1038/s41467-024-52483-3","RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Continuous directed evolution of base editors (BEs) has been successful in bacteria cells, but not yet in mammalian cells. Here, we report the development of a Continuous Directed Evolution system in Mammalian cells (CDEM). CDEM enables the BE evolution in a full-length manner with Cas9 nickase. We harness CDEM to evolve the deaminases of cytosine base editor BE3 and adenine base editors, ABEmax and ABE8e. The evolved cytidine deaminase variants on BE4 architecture show not only narrowed editing windows, but also higher editing purity and low off-target activity without a trade-off in on-targeting activity. The evolved ABEmax and ABE8e variants exhibit narrowed or shifted editing windows to different extents, and lower off-target effects. The results illustrate that CDEM is a simple but powerful approach to continuously evolve BEs without size restriction in the mammalian environment, which is advantageous over continuous directed evolution system in bacteria cells.
期刊介绍:
Nature Communications, an open-access journal, publishes high-quality research spanning all areas of the natural sciences. Papers featured in the journal showcase significant advances relevant to specialists in each respective field. With a 2-year impact factor of 16.6 (2022) and a median time of 8 days from submission to the first editorial decision, Nature Communications is committed to rapid dissemination of research findings. As a multidisciplinary journal, it welcomes contributions from biological, health, physical, chemical, Earth, social, mathematical, applied, and engineering sciences, aiming to highlight important breakthroughs within each domain.