Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Marburg, Germany.
Institute for Medical Bioinformatics and Biostatistic, Philipps-University, Marburg, Germany.
Cell Rep. 2022 May 31;39(9):110895. doi: 10.1016/j.celrep.2022.110895.
The ATP-dependent nucleosome remodeler Mi-2/CHD4 broadly modulates chromatin landscapes to repress transcription and to maintain genome integrity. Here we use individual nucleotide resolution crosslinking and immunoprecipitation (iCLIP) to show that Drosophila Mi-2 associates with thousands of mRNA molecules in vivo. Biochemical data reveal that recombinant dMi-2 preferentially binds to G-rich RNA molecules using two intrinsically disordered regions of unclear function. Pharmacological inhibition of transcription and RNase digestion approaches establish that RNA inhibits the association of dMi-2 with chromatin. We also show that RNA inhibits dMi-2-mediated nucleosome mobilization by competing with the nucleosome substrate. Importantly, this activity is shared by CHD4, the human homolog of dMi-2, strongly suggesting that RNA-mediated regulation of remodeler activity is an evolutionary conserved mechanism. Our data support a model in which RNA serves to protect actively transcribed regions of the genome from dMi-2/CHD4-mediated establishment of repressive chromatin structures.
ATP 依赖的核小体重塑酶 Mi-2/CHD4 广泛调节染色质景观，以抑制转录并维持基因组完整性。在这里，我们使用单个核苷酸分辨率交联和免疫沉淀（iCLIP）显示果蝇 Mi-2 与体内数千个 mRNA 分子相关联。生化数据表明，重组 dMi-2 优先使用两个功能不明的固有无序区域与富含 G 的 RNA 分子结合。转录的药理学抑制和 RNase 消化方法表明 RNA 抑制 dMi-2 与染色质的结合。我们还表明，RNA 通过与核小体底物竞争来抑制 dMi-2 介导的核小体迁移。重要的是，CHD4（dMi-2 的人类同源物）具有这种活性，这强烈表明 RNA 介导的重塑酶活性调节是一种进化保守的机制。我们的数据支持这样一种模型，即 RNA 用于保护基因组中活跃转录的区域免受 dMi-2/CHD4 介导的抑制性染色质结构的建立。
