Distinct localization of histone H3 acetylation and H3-K4 methylation to the transcription start sites in the human genome
Distinct localization of histone H3 acetylation and H3-K4 methylation to the transcription start sites in the human genome
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DOI：
10.1073/pnas.0401866101
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发表时间：
2004-05-11
影响因子：
11.1
通讯作者：
Jones, PA
中科院分区：
文献类型：
--
作者：
Liang, GN;Lin, JCY;Jones, PA
几乎1-2%的人类基因组位于转录起始位点两侧的500 bp内，而更大比例（约25%）可能通过延长RNA聚合酶转录。这一观察结果提出了一个问题，即基因组如何被包装到染色质中，以允许起始位点被调控机制识别，同时转录起始（而不是延伸）在25%的基因内DNA中被阻断。我们开发了一种名为ChAP的染色质扫描技术，将染色质免疫沉淀测定与任意引发的PCR结合起来，可以快速、公正地比较真核细胞核内的组蛋白修饰模式。组蛋白H3的甲基化赖氨酸4（K4）和乙酰化K9/14都高度定位于转录活性的人类基因的5'区域，但在起始位点的下游大大减少。我们的研究结果表明，人类基因的大的转录区域保持在一个脱乙酰化的构象，在延长聚合酶读取的区域。因此，描述广泛的组蛋白乙酰化和K4甲基化在整个转录单位的常见模型不适用于大多数人类基因。
Almost 1-2% of the human genome is located within 500 bp of either side of a transcription initiation site, whereas a far larger proportion (approximate to25%) is potentially transcribable by elongating RNA polymerases. This observation raises the question of how the genome is packaged into chromatin to allow start sites to be recognized by the regulatory machinery at the same time as transcription initiation, but not elongation, is blocked in the 25% of intragenic DNA. We developed a chromatin scanning technique called ChAP, coupling the chromatin immunoprecipitation assay with arbitrarily primed PCR, which allows for the rapid and unbiased comparison of histone modification patterns within the eukaryotic nucleus. Methylated lysine 4 (K4) and acetylated K9/14 of histone H3 were both highly localized to the 5' regions of transcriptionally active human genes but were greatly decreased downstream of the start sites. Our results suggest that the large transcribed regions of human genes are maintained in a deacetylated conformation in regions read by elongating polymerase. Common models depicting widespread histone acetylation and K4 methylation throughout the transcribed unit do not therefore apply to the majority of human genes.