Dual roles of p300 in chromatin assembly and transcriptional activation in cooperation with nucleosome assembly protein 1 in vitro
Dual roles of p300 in chromatin assembly and transcriptional activation in cooperation with nucleosome assembly protein 1 in vitro
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DOI：
10.1128/mcb.22.9.2974-2983.2002
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发表时间：
2002-05-01
影响因子：
5.3
通讯作者：
Montminy, M
中科院分区：
文献类型：
--
作者：
Asahara, H;Tartare-Deckert, S;Montminy, M
在酵母双杂交筛选，以确定蛋白结合的KIX结构域的辅激活蛋白p300，我们获得的cDNA编码核小体组装蛋白1（NAP-1），60 kDa的组蛋白H2 A-H2 B穿梭蛋白，促进组蛋白沉积。p300优先与H2 A-H2 B结合形式的NAP-1结合，而不是与未结合形式的NAP-1结合。NAP-1-p300复合物的形成被发现在S期增加，这表明p300在染色质组装中的潜在作用。在微球菌核酸酶和超螺旋测定中，除了p300促进有效的染色质组装在体外与NAP-1和ATP利用染色质组装和重塑因子，这种效果部分依赖于内在的组蛋白乙酰转移酶活性的p300。令人惊讶的是，NAP-1有效地抑制了核心组蛋白被p300乙酰化，这表明有效的组装需要NAP-1或p300本身的乙酰化。由于p300与NAP-1在体外刺激染色质模板转录中起协同作用，我们的研究结果表明NAP-1-p300复合物在促进染色质组装和转录激活中具有双重作用。
In a yeast two-hybrid screen to identify proteins that bind to the KIX domain of the coactivator p300, we obtained cDNAs encoding nucleosome assembly protein 1 (NAP-1), a 60-kDa histone H2A-H2B shuttling protein that promotes histone deposition. p300 associates preferentially with the H2A-H2B-bound form of NAP-1 rather than with the unbound form of NAP-1. Formation of NAP-1-p300 complexes was found to increase during S phase, suggesting a potential role for p300 in chromatin assembly. In micrococcal nuclease and supercoiling assays, addition of p300 promoted efficient chromatin assembly in vitro in conjunction with NAP-1 and ATP-utilizing chromatin assembly and remodeling factor; this effect was dependent in part on the intrinsic histone acetyltransferase activity of p300. Surprisingly, NAP-1 potently inhibited acetylation of core histones by p300, suggesting that efficient assembly requires acetylation of either NAP-1 or p300 itself. As p300 acted cooperatively with NAP-1 in stimulating transcription from a chromatin template in vitro, our results suggest a dual role of NAP-1-p300 complexes in promoting chromatin assembly and transcriptional activation.