Institute of Molecular Biology, University of Oregon, Eugene, OR 97403.
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.
Proc Natl Acad Sci U S A. 2020 May 26;117(21):11614-11623. doi: 10.1073/pnas.1918776117. Epub 2020 May 11.
Methylation of histone H3 lysine 27 (H3K27) is widely recognized as a transcriptionally repressive chromatin modification but the mechanism of repression remains unclear. We devised and implemented a forward genetic scheme to identify factors required for H3K27 methylation-mediated silencing in the filamentous fungus and identified a bromo-adjacent homology (BAH)-plant homeodomain (PHD)-containing protein, EPR-1 (effector of polycomb repression 1; NCU07505). EPR-1 associates with H3K27-methylated chromatin, and loss of EPR-1 de-represses H3K27-methylated genes without loss of H3K27 methylation. EPR-1 is not fungal-specific; orthologs of EPR-1 are present in a diverse array of eukaryotic lineages, suggesting an ancestral EPR-1 was a component of a primitive Polycomb repression pathway.
组蛋白 H3 赖氨酸 27（H3K27）的甲基化被广泛认为是一种转录抑制性染色质修饰，但抑制机制尚不清楚。我们设计并实施了一项正向遗传学方案，以鉴定丝状真菌中 H3K27 甲基化介导沉默所需的因子，并鉴定出一种溴相邻同源（BAH）-植物同源域（PHD）包含蛋白，EPR-1（多梳抑制效应因子 1；NCU07505）。EPR-1 与 H3K27 甲基化染色质相关联，并且 EPR-1 的缺失会解除 H3K27 甲基化基因的抑制，而不会失去 H3K27 甲基化。EPR-1 不是真菌特异性的；EPR-1 的同源物存在于各种真核生物谱系中，表明原始 EPR-1 是原始多梳抑制途径的一个组成部分。
