State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.
Experimental Center of Forestry in North China, Chinese Academy of Forestry, Beijing, 102300, China.
Adv Sci (Weinh). 2022 Feb;9(4):e2104789. doi: 10.1002/advs.202104789. Epub 2021 Dec 6.
Clustered regularly interspaced short palindromic repeat (CRISPR)/SaCas9 is the most popular tool for in vivo genome editing due to its high efficiency and small genome. The authors previously developed four SaCas9 orthologs as genome-editing tools. Here, to expand the targeting scope, they investigate the diversity of protospacer adjacent motifs (PAMs) by screening a list of 16 SaCas9 orthologs, twelve of which display editing activity in mammalian cells. They recognize five types of PAMs: NNGRRT, NNGRRR, NNGRC, NNGA, and NNGR. Importantly, SchCas9 recognizes the simple NNGR PAM, representing the most relaxed PAM preference of compact Cas9s to date. It is further demonstrated that SchCas9 enables efficient genome editing in multiple human cell lines. Altogether, these compact Cas9 tools offer a new option for both basic research and clinical applications.
成簇规律间隔短回文重复序列（CRISPR）/SaCas9 是最受欢迎的体内基因组编辑工具，因为它具有高效率和小基因组的特点。作者之前开发了四种 SaCas9 同源物作为基因组编辑工具。在这里，为了扩大靶向范围，他们通过筛选 16 种 SaCas9 同源物的列表来研究前导序列相邻基序（PAMs）的多样性，其中 12 种在哺乳动物细胞中具有编辑活性。他们识别出五种类型的 PAMs：NNGRRT、NNGRRR、NNGRC、NNGA 和 NNGR。重要的是，SchCas9 识别简单的 NNGR PAM，这代表了迄今为止紧凑型 Cas9 对 PAM 偏好最宽松的一种。进一步证明，SchCas9 能够在多种人类细胞系中进行有效的基因组编辑。总之，这些紧凑型 Cas9 工具为基础研究和临床应用提供了新的选择。
