The local density of H3K9me3 dictates the stability of HP1a condensates-mediated genomic interactions
The local density of H3K9me3 dictates the stability of HP1a condensates-mediated genomic interactions
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DOI：
10.1016/j.jgg.2023.04.006
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发表时间：
2023
影响因子：
5.9
通讯作者：
Hanhui Ma
中科院分区：
文献类型：
--
作者：
Ying Feng;Li Guo;Chen Yang;Hui Zheng;Xiao Xiao;Hanhui Ma
The human genome can be demarcated into domains based on distinct epigenetic states. The trimethy- lation of histone H3 lysine 9 (H3K9me3) is essential for the formation of constitutive heterochromatin nanodomains. However, the extent to which genomic regions require specific densities or degrees of H3K9me3 for stable interactions remains unclear. Here, we utilize CRISPR-based DNA imaging to inves- tigate the role of endogenous or ectopic H3K9me3 in chromatin dynamics and genomic interactions. We select three loci (IDR3, TCF3, and PR1) with distinct levels of H3K9me3 to examine the genomic interactions and association with endogenous Heterochromatin Protein 1 (HP1a) condensates. Our results demonstrate a positive correlation between the levels of H3K9me3 at the loci and their association with HP1a con- densates. By dual-color labeling and long-term tracking of IDR3 and PR1 loci, we find a periodical asso- ciation between the two ranging from one to three hours. Epigenetic perturbation-induced Genome organization (EpiGo)-KRAB introduces ~20 kilobases of H3K9me3 at the TCF3 locus, which is sufficient to establish a stable association between TCF3 and HP1a condensates. In addition, EpiGo-mediated H3K9me3 also leads to stable genomic interaction between IDR3 and TCF3. Briefly, these data suggest that the density of H3K9me3 could dictate the stability of interactions between genomic loci and HP1a condensates.
