FORMATION OF HYBRID NUCLEOSOMES CONTAINING NEW AND OLD HISTONES
FORMATION OF HYBRID NUCLEOSOMES CONTAINING NEW AND OLD HISTONES
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DOI：
10.1093/nar/9.16.4129
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发表时间：
1981-01-01
影响因子：
14.9
通讯作者：
HANCOCK, R
中科院分区：
文献类型：
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作者：
RUSSEV, G;HANCOCK, R
5 mM的羟基脲（HU）在不到1小时的时间内抑制小鼠P815细胞的DNA合成95-97%。然而，组蛋白合成仍在继续，新合成的组蛋白以对照指数生长细胞中的约20%的速率掺入非复制染色质中。为了研究这些组蛋白在染色质中的组织，在含有致密（15 N，13 C，2 H）-取代氨基酸的培养基中用5 mM HU处理P815细胞。在抑制DNA合成后，用（3 H）-精氨酸标记新合成的组蛋白。90分钟后收获细胞，制备单核和寡核小体，并在甲泛酰胺-三乙醇胺（MA-TEA）密度梯度上进行分析。3 H-标记组蛋白在这些梯度中的分布分析表明，它们被纳入含有新的和旧的组蛋白的杂交单核小体中。这些杂合核小体不是随机分布的，而是在某些染色质区域表现出一定的聚集趋势。
5 mM hydroxyurea (HU) inhibits DNA synthesis in mouse P815 cells by 95–97% in less than 1 hr. Nevertheless, histone synthesis continues and newly-synthesised histones are incorporated into non-replicating chromatin at a rate of about 20% of that in control exponentially-growing cells. To study the organization of these histones in chromatin, P815 cells were treated with 5 mM HU in medium containing dense (15N,13C,2H)-substituted amino acids. After inhibition of DNA synthesis, newly-synthesised histones were labelled with (3H)-arginine. The cells were harvested 90 min later, and mono- and oligonucleosomes were prepared and analysed on metrizamide-triethanolamine (MA-TEA) density gradients. Analysis of the distribution of3H-labelled histones in these gradients shows that they are incorporated into hybrid mononucleosomes containing both new and old histones. It is also shown that these hybrid nucleosomes are not randomly distributed, but show a certain tendency to be clustered in certain chromatin regions.