芝加哥大学汤玮欣团队的一项最新研究通过进化脱氨酶核酸识别热点的高精度胞嘧啶碱基编辑器。相关论文于2025年7月7日发表于国际顶尖学术期刊《自然—生物技术》杂志上。

在这里，课题组人员设计了大肠杆菌转移RNA特异性腺苷脱氨酶（TadA）的核苷酸和上下文特异性，以精确定位胞嘧啶编辑。通过定向进化战略性地采样多个核酸识别热点，研究组开发了16个TadA衍生的NCN特异性脱氨酶，涵盖了目标胞嘧啶的每种可能的-1和+1上下文，为编辑器化提供了按需脱氨酶选择。课题组将这些变异应用于(1)纠正ClinVar记录的疾病相关的T: A到C:G转变，在81.5%的病例中获得比传统CBEs更高的准确性；(2)在体外模拟两种癌症驱动突变——KRASG12D（ACC）和TP53R248Q （CCG）。他们的方法为潜在的临床应用提供了一种获取精确碱基编辑器的一般策略。

据介绍，碱基编辑器（BEs）是胞嘧啶或腺嘌呤脱氨酶与核酸酶受损的CRISPR蛋白的共价离子，介导基因组中C:G到T: A（CBEs）或A:T到G:C（ABEs）的位点特异性转化。现有的BEs在编辑窗口内修改所有的胞嘧啶或腺嘌呤，这限制了它们的精度。

附：英文原文

Title: High-precision cytosine base editors by evolving nucleic-acid-recognition hotspots in deaminase

Author: Wu, Yuan, Xiao, Yu-Lan, Tang, Weixin

Issue&Volume: 2025-07-07

Abstract: Base editors (BEs), covalent fusions of a cytosine or adenine deaminase with a nuclease-impaired CRISPR protein, mediate site-specific conversion of C:G to T:A (CBEs) or A:T to G:C (ABEs) in the genome. Existing BEs modify all cytosines or adenines within the editing window, which limits their precision. Here we engineer nucleotide and context specificity of the Escherichia coli transfer RNA-specific adenosine deaminase (TadA) to pinpoint cytosine editing. Strategically sampling multiple nucleic-acid-recognition hotspots through directed evolution, we develop 16 TadA-derived NCN-specific deaminases that cover every possible -1 and +1 context for a target cytosine, providing on-demand deaminase choices for editor customization. We apply these variants to (1) correct disease-associated T:A-to-C:G transitions documented by ClinVar, achieving greater accuracy than conventional CBEs in 81.5% of cases, and (2) model two cancer-driver mutations—KRASG12D (ACC) and TP53R248Q (CCG)—in vitro. Our approach offers a general strategy to access precise base editors for potential clinical applications.

DOI: 10.1038/s41587-025-02678-w

Source: https://www.nature.com/articles/s41587-025-02678-w