第一代胞嘧啶碱基编辑器BE1由rAPOBEC1 (大鼠胞嘧啶脱氨酶)和完全失去切割活性的dCas9组成 [1]，可以在体外实现有效的碱基编辑 (25%~40%)，但在哺乳动物 细胞内的编辑效率大大下降 (0.8%~7.7%)。 主要原因是 细胞内存在尿嘧啶DNA糖基化酶 (UDG)，UDG可识别U•G错配，并切割尿嘧啶和磷酸骨架之间的糖苷键，通过细胞内的碱基切除修复途径 (BER)将U逆转为C。 第二代胞嘧啶碱基编辑器：rAPOBEC1-XTEN-dCas9-UGI. 为了抑制UDG的作用，David Liu实验室 …

Base changes from C•G-to-T•A are mediated by cytosine base editors (CBEs) and base changes from A•T-to-G•C are mediated by adenine base editors (ABEs). How does this work? Through molecular biology teamwork.

Apr 23, 2021 · CRISPR-Cas9 cytidine and adenosine base editors (CBEs and ABEs) can disrupt genes without introducing double-stranded breaks by inactivating splice sites (BE-splice) or by introducing premature...

CRISPR-mediated DNA base editors, which include cytosine base editors (CBEs) and adenine base editors (ABEs), are promising tools that can induce point mutations at desired sites in a targeted manner to correct or disrupt gene expression.

碱基编辑器（Base Editor, BE）是一种能够实现基因组中特定碱基转换的基因编辑技术，它在不产生DNA双链断裂的情况下，通过特定的酶作用于目标碱基，实现碱基的直接替换。 这种技术极大地降低了随机插入外源基因的机率，可以更精确地进行点突变。 主要的碱基编辑器包括： 胞嘧啶碱基编辑器（Cytosine Base Editor, CBE）：CBE通过将胞嘧啶脱氨酶、尿嘧啶糖基化酶抑制子和改造的Cas9蛋白融合，其中的胞嘧啶脱氨酶能够使非互补链中的胞嘧啶（C）经脱氨基作用变成 …

饰酶的不同可分为胞嘧啶碱基编辑器(cytosine base editor, CBE)和腺嘌呤碱基编辑器(adenine base editor, ABE) 。 这两类碱基编辑系统利用胞嘧啶脱氨酶或人工进化的腺嘌呤脱氨酶对靶位点进行精准的碱基编辑，最终可以分 别实现C-T (G-A)或A-G (T-C)的碱基替换。

Apr 13, 2020 · Adenine base editors (ABEs) allow the efficient programmable conversion of adenine to guanine in target DNA without creating double strand breaks (DSBs) 1, 2, 3.

Jul 11, 2023 · In this study, we found ABE is capable of tolerating substantial deletions of REC2 and HNH domains, whereas CBE and PE systems are unable to tolerate these domain deletions. Furthermore, the sABE achieves base editing both in vitro and in vivo.

CBE and ABE lead to 1.1% and ≤0.1% indels, respectively, compared to much higher 4.3% indels from Cas9-HDR editing [21,22]. Research into the characterization of the observed undesired indels, bystander, and off-target editing as either because of BEs or the Cas protein is required.

Dec 20, 2024 · Currently developed are cytidine base editors (CBEs), mutating C to T; adenine base editors (ABEs), changing A to G; and prime editors (PEs), enabling arbitrary base conversions, precise insertions, and deletions.