染色质调控涉及有选择地招募染色质因子来促进DNA修复、复制和转录。在这里，我们展示了将无偏向功能基因组学与染色质免疫沉淀（CRISPR-ChIP）结合使用的实用性，以鉴定与哺乳动物细胞中活性染色质修饰相关的因子。具体来说，一个集成了感兴趣的顺式调控元件和单导RNA的报告基因耦合提供了一个染色质化的模板，用于直接读取与主动转录基因相关的组蛋白修饰调节因子，如H3K4me3和H3K79me2。通过CRISPR-ChIP，我们鉴定了所有非冗余的COMPASS复合物成员，这些成员对于H3K4me3的修饰是必需的，并且证明了RNA聚合酶II在维持H3K4me3中是可有可无的。由于H3K79me2在MLL易位引发的白血病细胞中具有潜在的致癌功能，使用CRISPR-ChIP，我们揭示了H3K79甲基化的两个不同调节单元的功能分区：一个由MLL融合蛋白依赖Menin调控的致癌DOT1L复合物，以及一个独立的内源性DOT1L复合物，其催化活性由MLLT10调控。总体而言，CRISPR-ChIP为无偏向地探究染色质调控机制提供了一个强大的工具。© 2023. 作者，在Springer Nature America, Inc.的独家许可下。

Chromatin regulation involves the selective recruitment of chromatin factors to facilitate DNA repair, replication and transcription. Here we demonstrate the utility of coupling unbiased functional genomics with chromatin immunoprecipitation (CRISPR-ChIP) to identify the factors associated with active chromatin modifications in mammalian cells. Specifically, an integrated reporter containing a cis-regulatory element of interest and a single guide RNA provide a chromatinized template for a direct readout for regulators of histone modifications associated with actively transcribed genes such as H3K4me3 and H3K79me2. With CRISPR-ChIP, we identify all the nonredundant COMPASS complex members required for H3K4me3 and demonstrate that RNA polymerase II is dispensable for the maintenance of H3K4me3. As H3K79me2 has a putative oncogenic function in leukemia cells driven by MLL translocations, using CRISPR-ChIP we reveal a functional partitioning of H3K79 methylation into two distinct regulatory units: an oncogenic DOT1L complex directed by the MLL fusion protein in a Menin-dependent manner and a separate endogenous DOT1L complex, where catalytic activity is directed by MLLT10. Overall, CRISPR-ChIP provides a powerful tool for the unbiased interrogation of the mechanisms underpinning chromatin regulation.© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.