Programmable deaminase-free base editors for G-to-Y conversion by engineered glycosylase  

作　　者：Huawei Tong Nana Liu Yinghui Wei Yingsi Zhou Yun Li Danni Wu Ming Jin Shuna Cui Hengbin Li Guoling Li Jingxing Zhou Yuan Yuan Hainan Zhang Linyu Shi Xuan Yao Hui Yang 

机构地区：[1]HuidaGene Therapeutics Co.,Ltd.,Shanghai 200131,China [2]Institute of Neuroscience,Center for Excellence in Brain Science and Intelligence Technology,Chinese Academy of Sciences,Shanghai 200031,China [3]Shanghai Center for Brain Science and Brain-Inspired Intelligence,Shanghai 200031,China [4]Department of Neurology and Institute of Neurology of First Affiliated Hospital,Institute of Neuroscience,and Fujian Key Laboratory of Molecular Neurology,Fujian Medical University,Fuzhou 350004,China

出　　处：《National Science Review》2023年第8期72-81,共10页国家科学评论（英文版）

基　　金：This work was supported by HuidaGene Therapeutics Co.,Ltd.(H.T.).

摘　　要：Current DNA base editors contain nuclease and DNA deaminase that enables deamination of cytosine(C)or adenine(A),but no method for guanine(G)or thymine(T)editing is available at present.Here we developed a deaminase-free glycosylase-based guanine base editor(gGBE)with G editing ability,by fusing Cas9 nickase with engineered N-methylpurine DNA glycosylase protein(MPG).By several rounds of MPG mutagenesis via unbiased and rational screening using an intron-split EGFP reporter,we demonstrated that gGBE with engineered MPG could increase G editing efficiency by more than 1500 fold.Furthermore,this gGBE exhibited high base editing efficiency(up to 81.2%)and high G-to-T or G-to-C(i.e.G-to-Y)conversion ratio(up to 0.95)in both cultured human cells and mouse embryos.Thus,we have provided a proof-of-concept of a new base editing approach by endowing the engineered DNA glycosylase the capability to selectively excise a new type of substrate.

关 键 词：GLYCOSYLASE base excision repair base editor depurination deaminase-free TRANSVERSION 

分 类 号：Q78[生物学—分子生物学]