Nucleosome assembly protein 1 exchanges histone H2A-H2B dimers and assists nucleosome sliding
Nucleosome assembly protein 1 exchanges histone H2A-H2B dimers and assists nucleosome sliding
复制标题
DOI：
10.1074/jbc.m411347200
复制
发表时间：
2005-01-21
影响因子：
4.8
通讯作者：
Luger, K
中科院分区：
文献类型：
--
作者：
Park, YJ;Chodaparambil, JV;Luger, K
真核染色质是高度动态的，即使在没有DNA复制的情况下也能迅速翻转。在这里，我们表明，酸性组蛋白伴侣核小体组装蛋白1（NAP-1）从酵母可逆地删除和取代组蛋白二聚体H2 A-H2 B或组蛋白变体二聚体从组装的核小体，导致活跃的组蛋白交换。H2 A-H2 B二聚体的瞬时去除促进核小体沿DNA沿着滑动到对生物学有利的位置。组蛋白交换以及核小体滑动不依赖于ATP，并且依赖于酵母NAP-1的C-末端酸性结构域的存在，即使该区域对于组蛋白结合和染色质组装不是必需的。我们的研究结果表明NAP-1（也许还有其他酸性组蛋白伴侣）在通过掺入组蛋白变体和协助核小体滑动来介导染色质流动性方面具有新的作用。NAP-1可以发挥非靶向作用（如果单独作用），也可以通过与其他因子的相互作用靶向基因组内的特定区域。
Eukaryotic chromatin is highly dynamic and turns over rapidly even in the absence of DNA replication. Here we show that the acidic histone chaperone nucleosome assembly protein 1 (NAP-1) from yeast reversibly removes and replaces histone protein dimer H2A-H2B or histone variant dimers from assembled nucleosomes, resulting in active histone exchange. Transient removal of H2A-H2B dimers facilitates nucleosome sliding along the DNA to a thermodynamically favorable position. Histone exchange as well as nucleosome sliding is independent of ATP and relies on the presence of the C-terminal acidic domain of yeast NAP-1, even though this region is not required for histone binding and chromatin assembly. Our results suggest a novel role for NAP-1 ( and perhaps other acidic histone chaperones) in mediating chromatin fluidity by incorporating histone variants and assisting nucleosome sliding. NAP-1 may function either untargeted ( if acting alone) or may be targeted to specific regions within the genome through interactions with additional factors.