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刘如谦团队利用噬菌体辅助进化产生更高效的腺嘌呤碱基编辑器
2020-03-18 13:15

美国哈佛大学刘如谦(David R. Liu)研究小组利用噬菌体辅助进化,产生了具有Cas结构域兼容性与活性提升的腺嘌呤碱基编辑器(ABE)。2020年3月17日,《自然—生物技术》杂志在线发表了这一最新研究成果。

ABE的应用受到脱氧腺苷脱氨酶组分与SpCas9以外Cas同系物的有限兼容性限制。研究人员使用噬菌体辅助的非连续和连续进化(PANCE和PACE)来改进了ABE7.10的脱氨酶成分,从而产生了ABE8e。与ABE7.10相比,ABE8e包含8个额外的突变,可将活性(kapp)提高590倍。
 
与各种Cas9或Cas12同源物配对时,ABE8e可以大大提高编辑效率。ABE8e比ABE7.10更具处理能力,这可能有益于筛选、调节区域的破坏和多重碱基编辑应用程序。
 
通过在TadA-8e域中引入其他突变,可以改善Cas9依赖性和非依赖性DNA脱靶编辑以及转录组范围的RNA脱靶编辑的一定增加。
 
最后,研究人员证明ABE8e可以有效地实现天然突变,从而在人细胞中BCL11A增强子或HBG启动子中上调胎儿血红蛋白的表达,而这些靶点被ABE7.10编辑的效果不佳。ABE8e增强了腺嘌呤碱基编辑的有效性和适用性。
 
附:英文原文

Title: Phage-assisted evolution of an adenine base editor with improved Cas domain compatibility and activity

Author: Michelle F. Richter, Kevin T. Zhao, Elliot Eton, Audrone Lapinaite, Gregory A. Newby, Benjamin W. Thuronyi, Christopher Wilson, Luke W. Koblan, Jing Zeng, Daniel E. Bauer, Jennifer A. Doudna, David R. Liu

Issue&Volume: 2020-03-16

Abstract: Applications of adenine base editors (ABEs) have been constrained by the limited compatibility of the deoxyadenosine deaminase component with Cas homologs other than SpCas9. We evolved the deaminase component of ABE7.10 using phage-assisted non-continuous and continuous evolution (PANCE and PACE), which resulted in ABE8e. ABE8e contains eight additional mutations that increase activity (kapp) 590-fold compared with that of ABE7.10. ABE8e offers substantially improved editing efficiencies when paired with a variety of Cas9 or Cas12 homologs. ABE8e is more processive than ABE7.10, which could benefit screening, disruption of regulatory regions and multiplex base editing applications. A modest increase in Cas9-dependent and -independent DNA off-target editing, and in transcriptome-wide RNA off-target editing can be ameliorated by the introduction of an additional mutation in the TadA-8e domain. Finally, we show that ABE8e can efficiently install natural mutations that upregulate fetal hemoglobin expression in the BCL11A enhancer or in the the HBG promoter in human cells, targets that were poorly edited with ABE7.10. ABE8e augments the effectiveness and applicability of adenine base editing.

DOI: 10.1038/s41587-020-0453-z

Source: https://www.nature.com/articles/s41587-020-0453-z

Nature Biotechnology:《自然—生物技术》,创刊于1996年。隶属于施普林格·自然出版集团,最新IF:68.164
官方网址:https://www.nature.com/nbt/
投稿链接:https://mts-nbt.nature.com/cgi-bin/main.plex


本期文章:《自然—生物技术》:Online/在线发表

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