Vidali G, Boffa L C, Bradbury E M, Allfrey V G
Proc Natl Acad Sci U S A. 1978 May;75(5):2239-43. doi: 10.1073/pnas.75.5.2239.
Exposure of HeLa cells to Na butyrate leads to an accumulation of multiacetylated forms of histones H3 and H4. Our studies of histone acetylation in HeLa S-3 cells show that 7 mM butyrate suppresses the deacetylation of histones without influencing the rate of radioactive acetate incorporation. An alteration in nucleosome structure in highly acetylated chromatin is indicated by an increased rate of DNA degradation by DNase I. A close association of acetylated histones with the DNase I-sensitive sequences is confirmed by the finding that histones remaining after limited DNase I digestion are depleted in the multiacetylated forms of histones H3 and H4. DNase I treatment has also been found to selectively release [3H]acetyl-labeled H3 and H4 from avian erythrocyte nuclei under conditions previously shown to preferentially degrade the globlin genes in erthyrocyte chromatin. Our results are consistent with the view that histone acetylation provides a key to the mechanism for altering chromatin structure at the nucleosomal level, and that this may explain the selective DNase I sensitivity of transcriptionally active DNA sequences in different cell types.
将HeLa细胞暴露于丁酸钠会导致组蛋白H3和H4的多乙酰化形式积累。我们对HeLa S-3细胞中组蛋白乙酰化的研究表明，7 mM丁酸钠可抑制组蛋白的去乙酰化，而不影响放射性乙酸掺入的速率。DNase I对DNA的降解速率增加表明高度乙酰化染色质中的核小体结构发生了改变。有限的DNase I消化后残留的组蛋白中组蛋白H3和H4的多乙酰化形式减少，这一发现证实了乙酰化组蛋白与DNase I敏感序列密切相关。还发现，在先前显示优先降解红细胞染色质中球蛋白基因的条件下，DNase I处理可从禽红细胞核中选择性释放[3H]乙酰标记的H3和H4。我们的结果与以下观点一致，即组蛋白乙酰化是在核小体水平改变染色质结构机制的关键，这可能解释了不同细胞类型中转录活性DNA序列对DNase I的选择性敏感性。
