Bioorganic Mechanisms of Chromatin Modifying Enzymes

染色质的调节性质和物理结构是由后调节蛋白动态调节的 核心组蛋白的翻译修饰。组蛋白的最新发现 去甲基酶引发了我们对应用调控知识的快速增长 和去除组蛋白修饰。赖氨酸特异性脱甲基酶1(LSD1)，也称为 KDM1和BCH110)在已知的人类组蛋白去甲基酶中是独一无二的 黄素依赖胺氧化酶家族的成员及其功能 作为转录激活因子或抑制因子，取决于赖氨酸残基的特性 这是去甲基化的。LSD1与多种基因的调控有关，从 核激素受体对造血分化因子的作用。此外，身份识别 肿瘤抑制基因P53作为LSD1介导的去甲基化的非组蛋白底物 使其生理作用进一步复杂化。初步迹象表明，LSD1的变化 活性可能在致癌转化中发挥作用强调了更好的 了解LSD1的功能。然而，人们对这种病毒的分子细节知之甚少 组蛋白去甲基酶的作用及其与蛋白质辅因子的相互作用。在这份提案中，我们 将建立对LSD1的这些分子细节的理解，长期目标是 设计LSD1活性调节器，使我们能够进一步探索其功能并评估 体内修饰LSD1活性的可能性。在目标1中，我们将调查有趣的 通过多肽的使用和定义的LSD1不同但高度调节的底物特异性 核小体底物。在目标2中，我们将研究LSD1活性的两个关键因素对LSD1活性的影响 伙伴蛋白、Corest和HDAC1，并确定Coest之间的相互作用位点， LSD1，以及促进核小体去甲基化的核小体。Corest将作为一种 了解相互作用的蛋白质如何影响LSD1特异性的模型系统 行动。总之，这些研究的结果将阐明LSD1功能的化学基础和 为进一步合理探讨LSD1的生理功能奠定了基础。

The regulatory nature and physical structure of chromatin are dynamically regulated by post- translational modifications of core histone proteins. The recent discovery of histone demethylases has initiated a rapid increase in our knowledge about the regulation of application and removal of histone modifications. Lysine-specific demethylase 1 (LSD1, also known as KDM1 and BCH110) is unique among known human histone demethylases in both its membership in the flavin-dependent amine oxidase family of enzymes and its ability to function as either a transcriptional activator or repressor, depending upon the identity of the lysine residue that is demethylated. LSD1 has been implicated in the regulation of a variety of genes, from nuclear hormone receptors to hematopoietic differentiation factors. In addition, the identification of the tumor-suppressor p53 as a non-histone substrate for LSD1-mediated demethylation adds further complexity to its physiological role. Preliminary indications that alterations in LSD1 activity may play a role in oncogenic transformation accentuate the need for a better understanding of the function of LSD1. However, little is known about the molecular details of both histone demethylase action and its interaction with protein cofactors. In this proposal we will establish an understanding of these molecular details of LSD1, with a long-term goal of designing modulators of LSD1 activity that will allow us to further probe its function and assess the potential for modifying LSD1 activity in vivo. In Aim 1 we will investigate the intriguingly diverse yet highly regulated substrate specificity of LSD1 through the use of peptides and defined nucleosomal substrates. In Aim 2 we will examine the effect on LSD1 activity by two of its key partner proteins, CoREST and HDAC1, and identify the interaction sites between CoREST, LSD1, and the nucleosome that facilitate nucleosomal demethylation. CoREST will serve as a model system for understanding how interacting proteins contribute to the specificity of LSD1 action. Together, the results of these studies will clarify the chemical basis for LSD1 function and provide a foundation to further probe the physiological function of LSD1 in a rational manner.