State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Nat Genet. 2011 Jun 5;43(7):715-9. doi: 10.1038/ng.854.
Polycomb group (PcG)-mediated histone H3 lysine 27 trimethylation (H3K27me3) has a key role in gene repression and developmental regulation. There is evidence that H3K27me3 is actively removed in plants, but it is not known how this occurs. Here we show that RELATIVE OF EARLY FLOWERING 6 (REF6), also known as Jumonji domain-containing protein 12 (JMJ12), specifically demethylates H3K27me3 and H3K27me2, whereas its metazoan counterparts, the KDM4 proteins, are H3K9 and H3K36 demethylases. Plants overexpressing REF6 resembled mutants defective in H3K27me3-mediated gene silencing. Genetic interaction tests indicated that REF6 acts downstream of H3K27me3 methyltransferases. Mutations in REF6 caused ectopic and increased H3K27me3 level and decreased mRNA expression of hundreds of genes involved in regulating developmental patterning and responses to various stimuli. Our work shows that plants and metazoans use conserved mechanisms to regulate H3K27me3 dynamics but use distinct subfamilies of enzymes.
多梳抑制复合物（PcG）介导的组蛋白 H3 赖氨酸 27 三甲基化（H3K27me3）在基因沉默和发育调控中起关键作用。有证据表明，H3K27me3 在植物中被主动去除，但具体机制尚不清楚。本文中，我们发现 RELATIVE OF EARLY FLOWERING 6（REF6），又名 Jumonji 结构域蛋白 12（JMJ12），特异性地去除 H3K27me3 和 H3K27me2，而其后生动物同源物 KDM4 蛋白则为 H3K9 和 H3K36 去甲基酶。过量表达 REF6 的植物与 H3K27me3 介导的基因沉默缺陷突变体表型相似。遗传互作测试表明 REF6 位于 H3K27me3 甲基转移酶的下游。REF6 突变导致数百个参与调控发育模式和响应各种刺激的基因的 H3K27me3 水平异位增加和 mRNA 表达降低。我们的工作表明，植物和后生动物使用保守的机制来调节 H3K27me3 动力学，但使用不同的酶亚家族。
