Discovering and Exploiting Selectivity within Tandem Bromodomains

项目摘要 这一行政补充请求的目标是提供一个最先进的结晶仪器， 布罗莫结构域与代谢衍生组蛋白酰基赖氨酸和小分子结合的结构研究 R35 GM 128840母公司奖项涵盖的抑制剂。布罗莫结构域调控的转录在 在临床试验中使用布罗莫结构域抑制剂对人类疾病有很好的认识。尽管取得了这些成就， 几个关键问题仍然存在。例如，布罗莫结构域不成比例地位于超- 增强剂。这种定位的基础是未知的，但重要的是，考虑到超级增强子富集在 具有致癌潜力的基因座。我们假设串联的溴结构域作为乙酰化的支架- 依赖染色质重组，例如，将启动子与增强子连接以驱动转录 （焦点1）。我们正在采取结构和生物物理的方法来研究串联的作用， 溴结构域在维持染色质构象中的作用。我们还假设代谢变化诱导 组蛋白上的翻译后修饰被布罗莫结构域“读取”。然而，酰化和蛋白质结合 溴结构域的特异性知之甚少。为了解决这个代谢问题，我们使用生物物理， 结构生物学和蛋白质组学技术来研究溴结构域酰化选择性和连接酰基辅酶A 代谢与转录（焦点2）。为了帮助机械调查，我们正在开发抑制剂， 溴结构域使用一种新的基于片段的NMR筛选策略，目前的重点是PBRM 1 溴结构域（焦点3）。这些化学工具将区分溴结构域的不同活性， 疾病模型，并导致靶向癌症中的PBRM 1轴的治疗。为了确定最佳条件 对于与配体结合的溴结构域的X射线结构测定， 提供了必要的平台和基础设施来筛选和自动化几个数量级的 比单个分配器所能执行的更大。此外，该筛选平台将用于协作 项目的化学生物学计划在威斯康星州医学院（MCW）和开放给所有MCW investigators.仪表将安装在受控的共用结晶仪表室中 由生物化学系。由于这种仪器将取代过时的14岁的仪器， 该房间配备有安装和操作所需的空间和基础设施。的 仪器将由博士水平的研究跟踪教师和工作人员维护。与其记录一致， 在生物物理研究基础设施和设施的重大投资，MCW已承诺资金， 总成本、所需仪器的放置空间、50%的维护费用和工资 支持培训和监督。

PROJECT SUMMARY The goal of this administrative supplement request is to provide a state-of-the-art crystallization instrument for structural studies of bromodomain binding to metabolically-derived histone acyl-lysines and small-molecule inhibitors covered by the R35 GM128840 parent award. The role of bromodomain-regulated transcription in human disease is well appreciated with bromodomain inhibitors in clinical trials. Despite these achievements, several critical questions remain. For example, bromodomains are localized disproportionately at super- enhancers. The basis of this localization is unknown but important given that super-enhancers are enriched at loci with oncogenic potential. We hypothesize that tandem bromodomains act as a scaffold for acetylation- dependent chromatin reorganization, for instance, joining promotors with enhancers to drive transcription (Focus 1). We are taking a structural and biophysical approach to investigate the role of tandem bromodomains in maintaining chromatin conformations. We also hypothesize that metabolic changes induce post-translational modifications on histones “read” by bromodomains. Yet, the acylation and protein binding specificity of bromodomains are poorly understood. To address this metabolic question, we use biophysical, structural biology, and proteomic techniques to investigate bromodomain acylation selectivity and link acyl-CoA metabolism with transcription (Focus 2). To aid mechanistic inquiries, we are developing inhibitors of bromodomains using a novel fragment-based NMR screening strategy with a current focus on the PBRM1 bromodomains (Focus 3). These chemical tools will distinguish the differential activities of bromodomains in disease models and lead to therapeutics targeting the PBRM1 axis in cancer. To determine optimal conditions toward x-ray structure determination of bromodomains bound to ligands, the proposed instrumentation provides the necessary platform and infrastructure to screen and automate several orders of magnitude greater than a single dispenser can perform. Furthermore, this screening platform will be used for collaborative projects for the Program in Chemical Biology at the Medical College of Wisconsin (MCW) and open to all MCW investigators. The instrumentation will be installed in the shared crystallization instrumentation room controlled by the Department of Biochemistry. As this instrumentation will replace obsolete 14-year-old instrumentation, this room is equipped with the necessary space and infrastructure for the installation and operation. The instrumentation will be maintained by PhD-level research-track faculty and staff. Consistent with its record of significant investments in biophysical research infrastructure and facilities, MCW has committed funds toward the total cost, space to house the requested instrument, 50% of the expenses for its maintenance, and salary support for training and supervision.