SpRY-mediated screens facilitate functional dissection of non-coding sequences at single-base resolution

作者：Yao Yao, Zhiwei Zhou, Xiaoling Wang, Zhirui Liu, Yixin Zhai, Xiaolin Chi, Jingyi Du, Liheng Luo, Zhigang Zhao, Xiaoyue Wang, Chaoyou Xue, Shuquan Rao · 发表于：Cell Genomics · 年份：2024 · DOI：10.1016/j.xgen.2024.100583 · 被引用次数：6 · 研究领域：CRISPR and Genetic Engineering、Plant Virus Research Studies、RNA and protein synthesis mechanisms

CRISPR mutagenesis screens conducted with SpCas9 and other nucleases have identified certain cis-regulatory elements and genetic variants but at a limited resolution due to the absence of protospacer adjacent motif (PAM) sequences. Here, leveraging the broad targeting scope of the near-PAMless SpRY variant, we have demonstrated that saturated SpRY mutagenesis and base editing screens can faithfully identify functional regulatory elements and essential genetic variants for target gene expression at single-base resolution. We further extended this methodology to investigate a genome-wide association study (GWAS) locus at 10q22.1 associated with a red blood cell trait, where we identified potential enhancers regulating HK1 gene expression, despite not all of these enhancers exhibiting typical chromatin signatures. More importantly, our saturated base editing screens pinpoint multiple causal variants within this locus that would otherwise be missed by Bayesian statistical fine-mapping. Our approach is generally applicable to functional interrogation of all non-coding genomic elements while complementing other high-coverage CRISPR screens.