Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan.
Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan; Department of Chemistry and Biochemistry, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan.
Cell Chem Biol. 2022 Jul 21;29(7):1153-1161.e5. doi: 10.1016/j.chembiol.2022.05.006. Epub 2022 Jun 20.
Histone lysine methylation is an epigenetic mark that can control gene expression. In particular, H3K9me3 contributes to transcriptional repression by regulating chromatin structure. Successful mitotic progression requires correct timing of chromatin structure changes, including epigenetic marks. However, spatiotemporal information on histone modifications in living cells remains limited. In this study, we created an FRET-based probe for live-cell imaging based on the HP1α chromodomain (HP1αCD), which binds to H3K9me3. The probe was incorporated into chromatin and the emission ratio decreased after treatment with histone methyltransferase inhibitors, indicating that it successfully traced dynamic changes in H3K9me3. Upon entry into mitosis, the probe's emission ratio transiently increased with a concomitant increase in H3K9me3, then exhibited a stepwise decrease, probably due to loss of HP1αCD binding caused by phosphorylation of H3S10 and demethylation of H3K9me3. This probe will be a useful tool for detecting dynamic changes in chromatin structure associated with HP1α.
组蛋白赖氨酸甲基化是一种表观遗传标记，可以控制基因表达。特别是，H3K9me3 通过调节染色质结构来促进转录抑制。有丝分裂的成功进行需要正确的染色质结构变化的时间，包括表观遗传标记。然而，活细胞中组蛋白修饰的时空信息仍然有限。在这项研究中，我们基于结合 H3K9me3 的 HP1α 染色质域 (HP1αCD) 创建了一种基于 FRET 的用于活细胞成像的探针。该探针被整合到染色质中，并且在用组蛋白甲基转移酶抑制剂处理后，发射比降低，表明它成功地追踪了 H3K9me3 的动态变化。进入有丝分裂后，探针的发射比短暂增加，伴随着 H3K9me3 的增加，然后呈逐步下降，可能是由于 H3S10 的磷酸化和 H3K9me3 的去甲基化导致 HP1αCD 结合的丧失。该探针将是检测与 HP1α 相关的染色质结构动态变化的有用工具。
