腺嘌呤碱基编辑器的优化与调控

Optimization and Regulation of Adenine Base Editors

腺嘌呤碱基编辑器(adenine base editor,ABE)是基于CRISPR/Cas系统开发的单碱基编辑系统。ABE通过人工进化的大肠杆菌中的腺嘌呤脱氨酶(tRNA specific adenosine deaminase,TadA*)与酿脓链球菌单切口酶(streptococcus pyogenes Cas9 nickase,nSpCas9)融合,实现了对基因组DNA的A·T>G·C单碱基替换。自开发以来,ABE经历了多轮进化以提升编辑效率。同时人们筛选出一系列针对ABE活性的调控因子(包括化学小分子、噬菌体多肽等),通过改变蛋白结构、提高蛋白表达水平或调控DNA修复通路等方式改善编辑效率和精度,增加编辑的可控性,拓宽了ABE的应用范围。目前,ABE及其调控手段已展现出巨大的基础研究价值与临床应用潜力。该文综述了ABE的优化历程及调控手段,并展望了ABE编辑技术的未来发展方向。

ABE(adenine base editor)is a single-base editing system based on the CRISPR/Cas system.ABEs are constructed by fusing artificially evolved TadA*(adenine deaminase)with Streptococcus pyogenes Cas nickase to achieve A·T>G·C single-base substitutions in genomic DNA.Since its development,ABE has undergone multiple rounds of evolution to improve its editing efficiency.Meanwhile,a series of regulatory factors targeting structural modules of ABE or related cellular pathways have been identified,enabling spatial-temporal control of their activity and greatly expanding their applications.Currently,ABEs,as well as regulatory factors,have shown great potential in basic research and clinical applications.This article reviews the evolution of ABE and the investigation of their regulatory approaches,and prospects for the development of adenine base editing technology.