project 2

既然人类基因组已经测序，我们必须学习理解这些信息 由其结构组织进行编码。细胞机制如何以及何时读取特定基因是至关重要的 细胞生命、分化和死亡的方方面面。有几种复杂的机制致力于解码 每个基因的结构组织中所固有的信息。组蛋白乙酰转移酶(HATS)是 翻译后乙酰化组蛋白和其他蛋白质的赖氨酸侧链的酶。组蛋白 伴侣是一组不同的酸性蛋白质，在组蛋白结合、核小体组装和 拆卸。HAT和伴侣活动协同作用调节的新兴概念 结合X射线结晶学方法在鲁格计划中解决染色质结构问题 生物物理学、酶学、分子生物学和生物化学。拟议的研究得到扩充，并 通过该方案内的其他两个项目的参与加以补充，并依赖于 由三个核心提供的服务。 POI的三个项目将追求三个共同目标。鲁格项目将检验第一个假设 (“分子伴侣动员组蛋白需要组蛋白乙酰化”) 量化组蛋白乙酰化对伴侣蛋白-组蛋白相互作用和核小体稳定性的影响。这 AIM还将揭示不同组蛋白伴侣蛋白之间的功能和机制差异 不同的生物功能。为了检验第二个假说(组蛋白伴侣调节组蛋白 乙酰基转移酶“)，我们将从结构和功能上表征伴侣和 HATS使用x射线结晶学和酶学。我们对假设3(组蛋白伴侣)的贡献 单核小体以外的功能“)将涉及染色质影响的生物物理特征 伴侣函数的紧致性。总而言之，该项目中的实验将产生前所未有的 组蛋白乙酰化、核小体组装和核小体相互联系的定量洞察 拆卸。

Now that the human genome has been sequenced, we must leam to understand the information that is encoded by its stmctural organization. How and when a particular gene is read by the cell's machinery is vital to all aspects of cell life, differentiation, and death. Several complex mechanisms are devoted to decoding the information that is inherent in each gene's stmctural organization. Histone acetyltransferases (HATs) are enzymes that posttranslationally acetylate lysine side chains of histones and other proteins. Histone chaperones are a diverse group of acidic proteins with roles in histone binding, nucleosome assembly and disassembly. The emerging concept that HAT and chaperone activities act synergistically to modulate chromatin stmcture v^dll be addressed in the Luger Project by combining x-ray crystallography mth methods in biophysics, enzymology, molecular biology, and biochemistry. The proposed studies are augmented and complemented through the participation of the other two Projects within this POI, and are dependent on the services provided by the three Cores. The three Projects of the POI will pursue three common aims. The Luger Project will test the first hypothesis ("histone mobilization by chaperones requires histone acetylation") by kinetically and thermodynamically quantifying the effects of histone acetylation on chaperone-histone interaction and nucleosome stability. This aim will also uncover functional and mechanistic differences between different histone chaperones with diverging biological functions. To test the second hypothesis ("histone chaperones regulate histone acetyltransferases"), we will stmcturally and functionally characterize the interaction between chaperones and HATs using x-ray crystallography and enzymology. Our contribution to hypothesis 3 ("histone chaperones function beyond the mononucleosome") will involve a biophysical characterization of the effect of chromatin compaction on chaperone function. Together, the experiments in this Project will yield unprecedented quantitative insight into the interconnection of histone acetylation, nucleosome assembly, and nucleosome disassembly.