Exploring novel regulatory mechanisms underlying enhancer activation and cell fate transition

探索增强子激活和细胞命运转变的新调控机制

• 批准号: 10259871
• 负责人: Kaixiang Cao
• 金额: $ 24.09万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-08 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10259871
• 关键词: 3-Dimensional; Animals; Architecture; Award; Binding; Binding Proteins; Biochemistry; Bioinformatics; Biological Assay; Biology; Bruck-de Lange syndrome; CRISPR screen; Cell Differentiation process; Cell Maintenance; Cells; Chromatin; Chromatin Structure; Data; Deposition; Development; Disease; Dose; Down-Regulation; ES Cell Line; Educational workshop; Embryonic Development; Enhancers; Ensure; Environment; Enzymes; Epigenetic Process; Equilibrium; Family; Gene Expression; Genes; Genetic Transcription; Genome; Genomic approach; Goals; Grant; Hi-C; Higher Order Chromatin Structure; Histone H3; Human; Instruction; KDM1A gene; Kabuki Make-Up Syndrome; Knock-out; Lead; Leadership; Lysine; Malignant Neoplasms; Mentors; Methylation; Modeling; Molecular; Mutation; Names; Output; Pathogenesis; Pathology; Pathway interactions; Phase; Play; Pluripotent Stem Cells; Postdoctoral Fellow; Process; Proteomics; Regulation; Research; Role; SET Domain; Stem Cell Factor; Testing; Thalassemia; Training; Transcriptional Regulation; Universities; Writing; base; cancer type; career; career development; chromosome conformation capture; clinical application; course development; developmental disease; driver mutation; embryonic stem cell; experience; genetic corepressor; genome wide screen; genome-wide; graduate student; high throughput screening; histone methyltransferase; human disease; inhibitor/antagonist; innovation; insight; loss of function; loss of function mutation; medical schools; member; new therapeutic target; novel; pluripotency; programs; protein complex; recruit; skills; stem cell biology; stem cell differentiation; stem cells; targeted treatment; therapy development; transcription factor; transcriptome

Project Summary/Abstract Misregulation of enhancer activity leads to various developmental disorders including thalassemia, Cornelia de Lange syndrome, and Kabuki syndrome. The major enhancer regulator Mll4 belongs to the family of the Su(var)3- 9, Enhancer-of-zeste, Trithorax (SET) domain containing histone methyltransferases named COMplex of Proteins ASsociated with Set1 (COMPASS), which places methylation marks at lysine 4 of histone H3 (H3K4). Mll4 is essential for mammalian development and its heterozygous loss-of-function mutations lead to various human diseases including Kabuki syndrome and cancer. I recently demonstrated that Mll4 is the major enzyme depositing mono-methylation at H3K4 (H3K4me1), an enhancer-decorating epigenetic mark whose function remains elusive. Moreover, I have defined catalytic activity dependent and independent functions of Mll4 in enhancer modulation and stem cell differentiation, and have unveiled an antagonism between enhancer-binding epigenetic machineries in transcriptional control that could underlie the developmental consequences of the heterozygous loss-of-function mutations of Mll4 in human disease. Based on these findings, I hypothesize that Mll4 cooperates with key transcription factors and epigenetic modifiers to modulate enhancer activity, chromatin structure, and transcriptional outputs during stem cell maintenance and differentiation. The studies proposed here aim to elucidate the molecular mechanisms of enhancer regulation, and to provide insights for developing novel therapies targeting diseases driven by the loss of function of epigenetic modifiers. Specifically, the outlined research will 1) elucidate how epigenetic marks impact enhancer functions and cell fate transition; 2) determine the role of higher order chromatin structure in stem cell maintenance and differentiation; 3) identify novel factors and pathways involved in modulating enhancer activity and determining cell fate. To achieve the long-term career goal of defining the epigenetic mechanisms underlying mammalian development and disease, I will acquire training in biochemistry, proteomics, bioinformatics, stem cell biology, and genome-wide screening during the mentored phase of this application. Moreover, I will participate in grant writing workshops and career development courses to strengthen my skills in writing and leadership. With the acquired training, I will be well- prepared for the task of delineating the machineries and mechanisms in modulating gene expression, chromatin structure, and cell fate determination in the independent R00 phase. In summary, the K99/R00 award, together with the experiences that I have garnered as a graduate student and postdoc, the guidance from the mentors and collaborators, and the superb research environment at Northwestern University's Feinberg School of Medicine, will ensure a successful transition for me to continue my independent scientific career in the field of stem cell biology and epigenetics.

项目摘要/摘要 增强剂活性的不正体导致各种发育障碍，包括丘陵，Cornelia de 兰格综合征和Kabuki综合征。主要增强子调节剂MLL4属于SU（VAR）3-家族 9，含有组蛋白甲基转移酶复合酶复合酶的trithorax（set）结构域的增强剂 与set1（指南针）相关的蛋白质，该蛋白将甲基化标记放在组蛋白H3的赖氨酸4（H3K4）处。 MLL4对于哺乳动物的发育至关重要，其杂合功能丧失突变导致不同 包括Kabuki综合征和癌症在内的人类疾病。我最近证明MLL4是主要酶 在H3K4（H3K4ME1）处沉积单甲基化，这是一种装饰表观遗传标记的功能 仍然难以捉摸。此外，我已经定义了MLL4在 增强子调制和干细胞分化，并在增强子结合之间揭示了拮抗作用 转录控制中的表观遗传机械可能是可能的基础 MLL4在人类疾病中的杂合丧失功能突变。根据这些发现，我假设 MLL4与关键转录因子和表观遗传修饰剂合作以调节增强剂活性，染色质 干细胞维持和分化过程中的结构和转录输出。研究提出 这里的目的是阐明增强子调节的分子机制，并为发展提供见解 由表观遗传修饰剂功能丧失驱动的针对疾病的新型疗法。具体来说，概述 研究将1）阐明表观遗传标记如何影响增强子功能和细胞命运转变； 2）确定 高阶染色质结构在干细胞维持和分化中的作用； 3）确定新因素 以及涉及调节增强子活性和确定细胞命运的途径。实现长期职业 定义哺乳动物发育和疾病的表观遗传机制的目标，我将获得 在生物化学，蛋白质组学，生物信息学，干细胞生物学和全基因组筛查中接受培训 该应用程序的指导阶段。此外，我将参加赠款写作研讨会和职业 开发课程，以增强我在写作和领导方面的技能。通过获得的培训，我会很好 为在调节基因表达，染色质中描述机制和机制的任务准备 在独立R00相中的结构和细胞命运确定。总而言之，K99/R00奖一起 有了我作为研究生和博士后获得的经验，导师的指导 和合作者，以及西北大学Feinberg学校的精湛研究环境 医学，将确保我成功过渡，以继续我的独立科学生涯 干细胞生物学和表观遗传学。