Genetic and Molecular Definition of Histone Modifying Enzyme Functions

组蛋白修饰酶功能的遗传学和分子定义

• 批准号: 9889968
• 负责人: SHARON Y. R. DENT
• 金额: $ 40万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9889968
• 关键词: Address; Affect; Alleles; Biochemical; Biological; Bromodomain; Cell Nucleus; Cells; Cerebellar Ataxia; Cerebellum; Chromatin; Complex; Development; Disease; Embryo; Enzymes; Foundations; Funding; Gene Expression; Gene Expression Regulation; Genetic; Genetic Transcription; Genome; Genomics; Goals; Growth; Histones; Human; Knowledge; Link; LoxP-flanked allele; Malignant Neoplasms; Mammalian Cell; Molecular; Mutant Strains Mice; Mutate; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Pathway interactions; Proteins; Research; Role; SAGA; Spinal; Tissues; Work; XCL1 gene; cell behavior; enzyme activity; flexibility; histone acetyltransferase; histone modification; human disease; insight; novel; novel therapeutics; programs; stem cells

Understanding how histone modifications are regulated is fundamentally important for understanding mechanisms of chromatin organization and gene regulation in both normal and disease states. The overall goal of our research is to address this challenging question, using genetic and molecular approaches to define which histone modifying enzymes, and by extension, which histone modifications, govern specific gene expression programs in particular biological contexts. Our work is focused largely on the Gcn5 histone acetyltransferase (HAT) and the USP22 histone deubiquitylase (DUB), which are both components of a large multiprotein assembly termed SAGA. Gcn5, USP22 and other SAGA components have been implicated in human maladies, including cancer and neurodegeneration, but the molecular mechanisms underlying such effects are not known. Over the past 20 years, we have created a novel toolkit of Gcn5 and USP22 mutant mice and cells, including null alleles, conditional (floxed) alleles, and point mutated alleles (in the Gcn5 HAT domain, the Gcn5 bromodomain, or the USP22 DUB domain) that affect the activity of these enzymes. Our studies of Gcn5 mutations revealed key insights to both transcriptional and non-transcriptional functions for this HAT during development, and most recently, they revealed important connections between Gcn5 and Myc functions both in normal stem cells and in cancer. Our USP22 mutant mice revealed that this DUB is also critical for embryo survival, but through different pathways than those affected by Gcn5 loss. Despite these advances, many significant gaps in knowledge still remain. We have only a partial view of which transcription programs require Gcn5 in mammalian cells. Moreover, Gcn5 is now known to be part of a second histone modifying complex called ATAC, but we do not know how Gcn5 is apportioned between these complexes or their relative roles in development or disease. We also have an incomplete understanding of the roles of USP22 and the SAGA DUB module in specific tissues such as the cerebellum, which is especially relevant since specific components of the SAGA DUB module are linked to a debilitating neurodegenerative disease, spinal cerebellar ataxia type 7 (SCA7). This MIRA will provide us stable and flexible funding to continue our genetic, biochemical, and molecular studies to address these critically important questions. In the longer term, definition of the normal functions of Gcn5 and USP22 will provide molecular foundations for development of new therapeutic options for diseases in which these factors are mis-regulated.

了解组蛋白修饰是如何调节的对于 了解正常和正常情况下染色质组织和基因调控的机制 疾病状态。我们研究的总体目标是解决这个具有挑战性的问题，使用 遗传和分子方法来定义哪些组蛋白修饰酶，并通过扩展， 哪些组蛋白修饰控制特定生物中的特定基因表达程序 上下文。我们的工作主要集中在 Gcn5 组蛋白乙酰转移酶 (HAT) 和 USP22 组蛋白去泛素化酶 (DUB)，两者都是大型多蛋白的组成部分 组件称为SAGA。 Gcn5、USP22 和其他 SAGA 组件均涉及 人类疾病，包括癌症和神经退行性疾病，但分子机制 造成这种影响的根本原因尚不清楚。在过去的 20 年里，我们创建了一个新颖的工具包 Gcn5 和 USP22 突变小鼠和细胞，包括无效等位基因、条件（floxed）等位基因和 点突变等位基因（在 Gcn5 HAT 结构域、Gcn5 bromodomain 或 USP22 DUB 中） 域）影响这些酶的活性。我们对 Gcn5 突变的研究揭示了关键 深入了解该 HAT 在开发过程中的转录和非转录功能， 最近，他们揭示了 Gcn5 和 Myc 功能之间的重要联系 正常干细胞和癌症中的干细胞。我们的 USP22 突变小鼠揭示了这种 DUB 也至关重要 胚胎存活，但通过与受 Gcn5 损失影响的途径不同的途径。尽管 尽管取得了这些进展，但知识方面仍然存在许多重大差距。我们只能看到片面的 哺乳动物细胞中哪些转录程序需要 Gcn5。此外，现在已知Gcn5 成为称为 ATAC 的第二个组蛋白修饰复合物的一部分，但我们不知道 Gcn5 是如何存在的 这些复合物之间的分配或它们在发育或疾病中的相对作用。我们也 对USP22和SAGA DUB模块在具体中的作用了解不完全 小脑等组织尤其重要，因为小脑的特定成分 SAGA DUB 模块与一种使人衰弱的神经退行性疾病（脊髓小脑）有关 7 型共济失调 (SCA7)。这个 MIRA 将为我们提供稳定和灵活的资金来继续我们的遗传、 生物化学和分子研究来解决这些至关重要的问题。在较长的时间里 术语，Gcn5 和 USP22 正常功能的定义将为 为这些因素被错误调节的疾病开发新的治疗方案。