PR-Set7 is a nucleosome-specific methyltransferase that modifies lysine 20 of histone H4 and is associated with silent chromatin
PR-Set7 is a nucleosome-specific methyltransferase that modifies lysine 20 of histone H4 and is associated with silent chromatin
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DOI：
10.1016/s1097-2765(02)00548-8
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发表时间：
2002-06-01
期刊：
影响因子：
16
通讯作者：
Reinberg, D
中科院分区：
文献类型：
--
作者：
Nishioka, K;Rice, JC;Reinberg, D
我们已经纯化了人组蛋白H4赖氨酸20甲基转移酶，并克隆了编码基因PR/SET 07。果蝇pr-set 7中的突变是致命的：第二次星内幼虫死亡与H4赖氨酸20甲基化的丧失同时发生，这表明PR-Set 7在发育中发挥着重要作用。转录活性区缺乏H4赖氨酸20甲基化，但修饰与多线染色体上的浓缩染色体区域一致，包括染色中心和常染色质臂。果蝇雄性X染色体在H4赖氨酸16处高度乙酰化，与雌性相比，其赖氨酸20甲基化水平显著降低。在体外，H4尾上赖氨酸20的甲基化和赖氨酸16的乙酰化是竞争性的。总之，这些结果支持了H4赖氨酸20的甲基化部分地通过排除H4尾上的相邻乙酰化来保持染色质沉默的假设。
We have purified a human histone H4 lysine 20 methyltransferase and cloned the encoding gene, PR/SET07. A mutation in Drosophila pr-set7 is lethal: second in-star larval death coincides with the loss of H4 lysine 20 methylation, indicating a fundamental role for PR-Set7 in development. Transcriptionally competent regions lack H4 lysine 20 methylation, but the modification coincided with condensed chromosomal regions on polytene chromosomes, including chromocenter and euchromatic arms. The Drosophila male X chromosome, which is hyperacetylated at H4 lysine 16, has significantly decreased levels of lysine 20 methylation compared to that of females. In vitro, methylation of lysine 20 and acetylation of lysine 16 on the H4 tail are competitive. Taken together, these results support the hypothesis that methylation of H4 lysine 20 maintains silent chromatin, in part, by precluding neighboring acetylation on the H4 tail.