Histone H3 lysine 9 methylation and HP1γ are associated with transcription elongation through mammalian chromatin
Histone H3 lysine 9 methylation and HP1γ are associated with transcription elongation through mammalian chromatin
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DOI：
10.1016/j.molcel.2005.06.011
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发表时间：
2005-08-05
期刊：
影响因子：
16
通讯作者：
Blobel, GA
中科院分区：
文献类型：
--
作者：
Vakoc, CR;Mandat, SA;Blobel, GA
组蛋白的甲基化调节染色质的结构和功能。然而，组蛋白H3在赖氨酸4、36和79上的甲基化与基因激活有关，H3在赖氨酸9和27上的甲基化以及组蛋白H4在赖氨酸20上的甲基化与异染色质和常染色质内的一些受抑制的基因有关。在这里，我们表明，H3 K9的二-和三甲基化发生在哺乳动物染色质中的活性基因的转录区域。这种修饰是动态的，因为它在转录激活过程中增加，并在基因阻遏时迅速去除。异染色质蛋白1 γ（HP 1 γ），一种含有识别H3 K9甲基化的染色体结构域的蛋白质，也存在于所有检测的活性基因的转录区。HP 1 γ和H3 K9甲基化的存在都依赖于RNA聚合酶II的延伸。这些发现证明了H3 K9甲基化和HP 1 γ在转录激活中的新作用。
Methylation of histones modulates chromatin structure and function. Whereas methylation of histone H3 on lysines 4, 36, and 79 has been linked with gene activation, methylation of H3 on lysines 9 and 27 and histone H4 on lysine 20 is associated with heterochromatin and some repressed genes within euchromatin. Here, we show that H3K9 di- and trimethylation occur in the transcribed region of active genes in mammalian chromatin. This modification is dynamic, as it increases during activation of transcription and is rapidly removed upon gene repression. Heterochromatin Protein 1 gamma (HP1 gamma), a protein containing a chromodomain that recognizes H3K9 methylation, is also present in the transcribed region of all active genes examined. Both the presence of HP1 gamma and H3K9 methylation are dependent upon elongation by RNA polymerase II. These findings demonstrate novel roles for H3K9 methylation and HP1 gamma in transcription activation.