美国华盛顿大学Jay Shendure等研究人员合作揭示先导编辑的染色质背景依赖性调控和表观遗传操控。相关论文于2024年4月11日在线发表在《细胞》杂志上。

研究人员致力于详尽描述顺式染色质环境对基因组工程精确工具（先导编辑）的影响。研究人员使用一种高灵敏度的方法来绘制了随机整合报告的基因组位置图，发现了巨大的位置效应，例如，对于相同的目标位点和编辑，编辑效率从0%到94%不等。染色质标记（如H3K79me2和H3K9me3）可以很好地预测位置对先导编辑效率的影响。

接下来，研究人员开发了一个多重扰动框架，以评估反式作用因子与顺式染色质环境对编辑结果的相互作用。将这一框架应用于DNA修复因子，研究人员发现HLTF是先导编辑的环境依赖性抑制因子。

最后，一些证据表明，活跃的转录伸长会增强先导编辑。与此相一致，该研究表明，在先导编辑之前，通过CRISPR介导的沉默或激活，可以分别有力地降低或提高先导编辑的效率。

附：英文原文

Title: Chromatin context-dependent regulation and epigenetic manipulation of prime editing

Author: Xiaoyi Li, Wei Chen, Beth K. Martin, Diego Calderon, Choli Lee, Junhong Choi, Florence M. Chardon, Troy A. McDiarmid, Riza M. Daza, Haedong Kim, Jean-Benot Lalanne, Jenny F. Nathans, David S. Lee, Jay Shendure

Issue&Volume: 2024-04-11

Abstract: We set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing, a precise genome engineering tool. Using a highly sensitive method for mapping the genomic locations of randomly integrated reporters, we discover massive position effects, exemplified by editing efficiencies ranging from ～0% to 94% for an identical target site and edit. Position effects on prime editing efficiency are well predicted by chromatin marks, e.g., positively by H3K79me2 and negatively by H3K9me3. Next, we developed a multiplex perturbational framework to assess the interaction of trans-acting factors with the cis-chromatin environment on editing outcomes. Applying this framework to DNA repair factors, we identify HLTF as a context-dependent repressor of prime editing. Finally, several lines of evidence suggest that active transcriptional elongation enhances prime editing. Consistent with this, we show we can robustly decrease or increase the efficiency of prime editing by preceding it with CRISPR-mediated silencing or activation, respectively.

DOI: 10.1016/j.cell.2024.03.020

Source: https://www.cell.com/cell/fulltext/S0092-8674(24)00311-8