Understanding how two related mammalian histone acetyl transferase co-activators, SAGA and ATAC, differentially regulate chromatin dynamics and transcription

了解两种相关的哺乳动物组蛋白乙酰转移酶共激活剂 SAGA 和 ATAC 如何差异调节染色质动力学和转录

• 批准号: 10092202
• 负责人: Michael Guy Poirier
• 金额: $ 34.87万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10092202
• 关键词: Acetylation; Acetyltransferase; Affect; Aging; Binding; Biochemical; Biochemistry; Biophysics; Cardiac Myocytes; Catalytic Domain; Cells; Cellular biology; Chromatin; Chromatin Structure; Complex; DNA Repair; DNA biosynthesis; Data; Development; Disease; Drosophila genus; Drug resistance; Enhancers; Ensure; Epigenetic Process; Fluorescence; Foundations; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genome; Genome Stability; HIV; Heart Diseases; Histone Acetylation; Histones; Human; In Vitro; Individual; Knock-out; Knowledge; Malignant Neoplasms; Mammalian Cell; Messenger RNA; Methods; Modification; Molecular; Multiprotein Complexes; Mus; Mutagenesis; Mutation; N-terminal; Nature; Nucleosomes; Peptides; Pharmacotherapy; Post-Translational Protein Processing; Property; Protein Subunits; Proteins; Publishing; Reader; Reading; Recombinants; Regulation; Research; SAGA; Site; Structure; Tail; Techniques; Transcription Coactivator; Transcriptional Regulation; Transferase; Translations; Work; Writing; XCL1 gene; base; design; embryonic stem cell; epigenetic drug; epigenetic therapy; genome-wide; genome-wide analysis; histone acetyltransferase; in vivo; insight; multidisciplinary; mutant; nerve stem cell; novel therapeutics; preference; preservation; promoter; protein function; single molecule; success; tumorigenesis

UNDERSTANDING HOW TWO RELATED HISTONE ACETYL TRANSFERASE CO-ACTIVATORS, SAGA AND ATAC, DIFFERENTIALLY REGULATE CHROMATIN DYNAMICS AND TRANSCRIPTION PROJECT SUMMARY Histone post translational modifications (PTMs) and the complexes that install them and read them, control many aspects of eukaryotic genome function including transcription, DNA repair and replication. As a result of histone PTM writer’s broad functions, they are essential in organismal development, aging and numerous diseases including cancer, heart disease, and even HIV integration. The majority of histone writers target the disordered N-terminal tail regions. Numerous histone writers have been identified and studied genetically, biochemically and structurally. Surprisingly, mechanistic studies are primarily limited to interactions between histone tail peptides and catalytic subunits, resulting in key gaps in understanding how histone readers/writers within their full native complexes interact and regulate chromatin structure, dynamics, accessibility and transcription. Recently, we developed the methods to purify biochemical quantities of endogenous human SAGA and ATAC complexes, which are related, but functionally distinct essential transcription co-activators. This allows us to quantitatively investigate how these two large multi-subunit complexes function relative to their common catalytic subunit, KAT2A, alone. Leveraging this, we recently found that (i) The endogenous SAGA and ATAC complexes acetylate histone octamers much more efficiently than the KAT2A acetyltransferase alone. (ii) The acetylation efficiency of endogenous SAGA and ATAC complexes are dramatically inhibited by unmodified nucleosomes relative to unmodified histone octamer. (iii) The SAGA and ATAC HAT modules acetylate histone H3K9 similarly relative to KAT2A alone, but the SAGA HAT module acetylates H3K9 in unmodified nucleosomes much more efficiently than the ATAC HAT complex or KAT2A alone. (iv) In mouse ES cells, deletion of the SAGA HAT module does not strongly affect global H3K9 acetylation, while deletion of the ATAC HAT module results in a significant reduction in overall H3K9 acetylation. These findings have led us to investigate the hypothesis that histone PTM readers/writers target chromatin properties through their accessory proteins to dynamically influence chromatin dynamics and accessibility. (1) Determine the chromatin properties that regulate reading and writing by the mammalian HAT complex SAGA. (2) Elucidate how the different subunits of the related mammalian HAT complexes, SAGA and ATAC, differentially control their targeting and chromatin modifying activity. (3) Determine the functional differences between SAGA and ATAC in mouse embryonic stem cells and during their differentiation. Together these aims provide a mechanistic and functional foundation for understanding of how two key transcriptional co-activators, SAGA and ATAC, differentially regulate chromatin dynamic and transcription.

了解两种相关的组蛋白乙酰转移酶共激活剂，佐贺 和ATAC，差异调节染色质的染色质构象和转换 项目摘要 组蛋白翻译后修饰（PTM）和安装它们并读取它们的复合物， 真核生物基因组功能的许多方面，包括转录、DNA修复和复制。的结果 组蛋白PTM作家的广泛功能，他们是必不可少的生物体发育，老化和众多 包括癌症，心脏病，甚至艾滋病毒的整合。大多数组蛋白作者的目标是 无序的N-末端尾部区域。许多组蛋白作者已被确定和遗传学研究， 在生物化学和结构上。令人惊讶的是，机制研究主要限于 组蛋白尾肽和催化亚基，导致理解组蛋白读者/作家如何 在其完整的天然复合物内相互作用并调节染色质结构、动力学、可及性和 转录。近年来，我们发展了纯化内源性人体生化量的方法， 佐贺和ATAC复合物，它们是相关的，但功能不同的必需转录共激活因子。 这使我们能够定量研究这两个大的多亚基复合物相对于 它们共同的催化亚基KAT 2A。利用这个，我们最近发现， (i)内源性佐贺和ATAC复合物乙酰化组蛋白八聚体比乙酰化组蛋白八聚体更有效。 单独的KAT 2A乙酰转移酶。(ii)内源性佐贺和ATAC复合物的乙酰化效率为 相对于未修饰的组蛋白八聚体，未修饰的核小体显著抑制。(iii)佐贺和 ATAC HAT模块相对于单独的KAT 2A类似地乙酰化组蛋白H3 K9，但是佐贺HAT模块 乙酰化未修饰核小体中的H3 K9比ATAC HAT复合物或KAT 2A更有效 一个人(iv)在小鼠ES细胞中，佐贺HAT模块的缺失不会强烈影响全局H3 K9 乙酰化，而ATAC HAT模块的缺失导致总体H3 K9 乙酰化 这些发现使我们研究了组蛋白PTM阅读器/写入器靶向染色质的假设 通过其辅助蛋白质的性质，动态地影响染色质动力学和可及性。 (1)确定哺乳动物HAT复合物调控阅读和写的染色质特性 佐贺。 (2)阐明相关哺乳动物HAT复合物佐贺和ATAC的不同亚基， 差异地控制它们的靶向和染色质修饰活性。 (3)确定佐贺和ATAC在小鼠胚胎干细胞中的功能差异， 他们的区别。 这些目标一起为理解两个关键的 转录共激活因子佐贺和ATAC差异调节染色质动力学和转录。