Histone Modification and Changes in Chromatin: Silencing of Tumor Suppressor Gene

真核生物的基因组DNA必须高度紧凑，才能包装在细胞的细胞核内。这 紧凑是通过形成一种称为染色质的复杂核蛋白结构来实现的。 染色质是一种高度动态的结构，它对细胞过程施加强大的影响，包括 获取染色体DNA。染色质的主要蛋白质成分是核心组蛋白H2A， H2B、H3和H4。核心组蛋白的翻译后修饰是一种重要的机制 哪种染色质结构受到调节。核心组蛋白已经被证明经历了几种类型的 修饰如乙酰化、甲基化、磷酸化、泛素化和ADP-核糖化。在……里面 此外，这些修饰经常在核心组蛋白的多个位置发现。我们的主要重点是 目前的建议是使用灵敏的质谱学技术作为基础 组蛋白翻译后修饰的全面鉴定、作图和表征。 我们在这些研究中的最初目标是使用质谱学来分析从牛中分离的核心组蛋白 胸腺。这将允许识别和绘制组蛋白翻译后的完整谱。 在更高的真核细胞染色质中存在修饰。因为新的修饰部位是 经过鉴定，它们在体内的功能特性将在酵母中完成，利用独特的 在基因上操纵这种有机体中的核心组蛋白的能力。 许多观察表明，染色质结构的适当调节在 预防癌症特有的不受控制的细胞生长。因此，我们建议进行实验， 寻求确定组蛋白修饰的范围或模式中与以下相关的特征变化 慢性淋巴细胞白血病。 正如本计划项目的其他部分所述，染色质结构的修改正在进行中 探索作为一种潜在的化疗策略。组蛋白脱乙酰酶的小分子抑制剂 显示出在控制癌细胞生长和分化方面的潜力。要最有效地利用这些资源 对于化合物，更准确地描述由其诱导的组蛋白修饰的变化是至关重要的 通过这些药物。因此，我们建议使用质谱学来全面表征 化疗药物处理白血病细胞引起的组蛋白修饰的变化 目标染色质结构。

The genomic DNA of eukaryotes must be highly compacted for packaging within the nuclei of cells. This compaction is achieved through the formation of a complex nucleoprotein structure known as chromatin. Chromatin is a highly dynamic structure that exerts a powerful influence over cellular processes that involve accessing chromosomal DNA. The primary protein components of chromatin are the core histones H2A, H2B, H3 and H4. The post-translational modification of the core histones is an important mechanism by which chromatin structure is regulated. The core histones have been shown to undergo several types of modification such as acetylation, methylation, phosphorylation, ubiquitination and ADP-ribosylation. In addition, these modifications are often found at multiple sites in the core histones. The main focus of our current proposal is to use the sensitive technique of mass spectrometry as a foundation for the comprehensive identification, mapping and characterization of histone post-translational modifications. Our initial aim in these studies is to use mass spectrometry to analyze core histones isolated from bovine thymus. This will allow for the identification and mapping of the complete spectrum of histone posttranslational modifications present in higher eukaryotic chromatin. As novel sites of modification are identified, the characterization of their in vivo function will be done in yeast, taking advantage of the unique ability to genetically manipulate the core histones in this organism. Many observations point to the critical role that the proper regulation of chromatin structure plays in preventing the uncontrolled cell growth characteristic of cancer. Therefore, we propose experiments that seek to identify characteristic alterations in the extent or pattern of histone modifications that correlate with Chronic Lymphocytic Leukemia. As described in other sections of this program project, the modification of chromatin structure is being explored as a potential chemotherapeutic strategy. Small molecule inhibitors of histone deacetylases have shown potential in controlling the growth and differentiation of cancer cells. To most effectively utilize these compounds, it is vital to more precisely characterize the alterations in histone modifications that are induced by these drugs. Therefore, we propose to use mass spectrometry to comprehensively characterize the changes in histone modification that result from the treatment of leukemia cells with chemotherapeutic agents that target chromatin structure.