Gcn5 promotes acetylation, eviction, and methylation of nucleosomes in transcribed coding regions
Gcn5 promotes acetylation, eviction, and methylation of nucleosomes in transcribed coding regions
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DOI：
10.1016/j.molcel.2006.11.020
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发表时间：
2007-01-12
期刊：
影响因子：
16
通讯作者：
Hinnebusch, Alan G.
中科院分区：
文献类型：
--
作者：
Govind, Chhabi K.;Zhang, Fan;Hinnebusch, Alan G.
我们的报告，辅激活佐贺，含有HAT Gcn 5 p，占据GAL土地ARG 1编码序列在转录诱导，依赖于PIC组装和Ser 5磷酸化的Pol II CTD。GAL 1的诱导增加ORF中每个核小体的H3乙酰化，这依赖于佐贺完整性，而不是替代的Gcn 5 p-HAT复合物ADA。出乎意料的是，由于与ORE相关的多个HDA的相反活性，ARG 1编码序列中的H3乙酰化在诱导期间不增加。值得注意的是，Gcn 5 p的失活减少了从GAL 1和从GAL 1启动子转录的长（类似于8 kb）ORF的核小体驱逐。这与长ORF的3'端Pol II占据减少和mRNA产生选择性减少有关。Gcn 5 p还增强ARG 1 ORF和大量组蛋白中的H3-K4三甲基化。因此，Gcn 5 p，最有可能在佐贺中，刺激转录的编码序列中的核小体的修饰和驱逐，并促进Pol II延伸。
We report that coactivator SAGA, containing the HAT Gcn5p, occupies the GAL land ARG1 coding sequences during transcriptional induction, dependent on PIC assembly and Ser5 phosphorylation of the Pol II CTD. Induction of GAL1 increases H3 acetylation per nucleosome in the ORF, dependent on SAGA integrity but not the alternative Gcn5p-HAT complex ADA. Unexpectedly, H3 acetylation in ARG1 coding sequences does not increase during induction due to the opposing activities of multiple HDAs associated with the ORE Remarkably, inactivation of Gcn5p decreases nucleosome eviction from both GAL1 and a long (similar to 8 kb) ORF transcribed from the GAL1 promoter. This is associated with reduced Pol II occupancy at the 3' end and decreased mRNA production, selectively, for the long ORF. Gcn5p also enhances H3-K4 trimethylation in the ARG1 ORF and bulk histones. Thus, Gcn5p, most likely in SAGA, stimulates modification and eviction of nucleosomes in transcribed coding sequences and promotes Pol II elongation.