Role of UTX condensation in chromatin regulation

UTX 缩合在染色质调控中的作用

• 批准号: 10365699
• 负责人: Hao Jiang
• 金额: $ 41.88万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10365699
• 关键词: Binding; Biochemical; Biological; Biological Assay; Biological Process; Biophysics; CRISPR/Cas technology; Cancer Biology; Cancer Cell Growth; Cell Differentiation process; Cells; ChIP-seq; Chimeric Proteins; Chromatin; Core Protein; Development; Developmental Process; Disease; EP300 gene; Engineering; Enhancers; Gene Expression; Genes; Genetic Transcription; Genomics; Histones; Homologous Gene; Human; Impairment; In Vitro; Kabuki Make-Up Syndrome; Liquid substance; Malignant Neoplasms; Mediating; Methylation; Methyltransferase; Missense Mutation; Molecular; Mus; Mutate; Mutation; Neurodevelopmental Disorder; Patients; Phase; Physical condensation; Physiological; Process; Property; Protein Dynamics; Proteins; Publications; RNA Splicing; Regulation; Role; Stem Cell Development; System; Transcription Initiation Site; Tumor Suppression; Tumor Suppressor Proteins; Variant; Work; Y Chromosome; biophysical analysis; biophysical properties; cancer cell; chromatin modification; demethylation; embryonic stem cell; genome editing; insight; mutant; neoplastic cell; novel; programs; reconstitution; recruit; stem cell differentiation; tumor; tumorigenesis

PROJECT ABSTRACT UTX/KDM6A is an important tumor suppressor and developmental regulator, and is frequently mutated in human cancers and certain neurodevelopmental disorders including Kabuki syndrome. Though UTX is a histone H3K27 demethylase, the demethylase activity is often dispensable in mediating tumor suppression and developmental regulation, and the key molecular activity of UTX in these processes remains elusive. UTX is thought to regulate chromatin activity by associating with and coordinating the function of MLL3/KMT2C and MLL4/KMT2D, the major H3K4 mono-methylase at enhancers, and the p300 histone acetyltransferase, all of which are also frequently mutated in human cancers. In our preliminary studies, we found that the tumor suppressive activity of UTX requires its phase separation property conferred by its core Intrinsically Disordered Region (cIDR). Endogenous UTX forms dynamic condensates in mouse embryonic stem cells (ESCs) and its cIDR is important for ESC differentiation. UTX and MLL4 form co-condensates that enhance the H3K4 mono-methylation activity. We also found that UTY, the Y chromosome homolog of UTX, has weaker tumor suppressive activity that is associated with formation of less dynamic condensates. These results let us formulate our central hypothesis that UTX needs to be in condensates with appropriate biophysical properties to be active in regulating gene expression on chromatin in regulating tumorigenesis and stem cell differentiation. We proposal two Specific Aims. Aim 1. Determine the mechanisms by which UTX condensation regulates chromatin activity. We will determine how UTX condensation regulates chromatin modification activities by biochemical reconstitution, and also through integrative analyses of multiple levels of chromatin activity in both transduced cancer cells and endogenous Utx-edited ESCs. Aim 2. Determine how biophysical properties of the UTX condensates regulate its biological activities. We will study biophysical properties of UTX WT and variant condensates and its associated co-activators. We will determine impacts of condensate properties on biological activities at different levels in in both transduced cancer cells and endogenous Utx-edited ESCs. We will also examine effect of disease-associated missense mutations of UTX on condensate properties.

项目摘要 UTX/KDM6A 是一种重要的肿瘤抑制因子和发育调节因子，并且经常被 在人类癌症和某些神经发育障碍（包括歌舞伎）中发生突变 综合症。虽然 UTX 是一种组蛋白 H3K27 去甲基化酶，但去甲基化酶活性通常 在介导肿瘤抑制和发育调节中不可或缺的关键分子 UTX 在这些过程中的活动仍然难以捉摸。 UTX被认为可以调节染色质活性 通过关联和协调 MLL3/KMT2C 和 MLL4/KMT2D 的功能，主要 增强子处的 H3K4 单甲基化酶和 p300 组蛋白乙酰转移酶，所有这些都是 在人类癌症中也经常发生突变。在我们的初步研究中，我们发现肿瘤 UTX 的抑制活性需要其核心赋予的相分离特性 本质无序区域（cIDR）。内源性 UTX 在小鼠体内形成动态冷凝物 胚胎干细胞 (ESC) 及其 cIDR 对于 ESC 分化很重要。 UTX 和 MLL4 形成增强 H3K4 单甲基化活性的共缩合物。我们还发现UTY， UTX 的 Y 染色体同源物，具有较弱的肿瘤抑制活性，这与 形成动力较小的冷凝物。这些结果让我们制定了我们的中心假设 UTX 需要处于具有适当生物物理特性的冷凝物中才能发挥活性 调节染色质上的基因表达以调节肿瘤发生和干细胞分化。 我们提出两个具体目标。 目标 1. 确定 UTX 缩合调节染色质的机制 活动。我们将通过以下方式确定UTX缩合如何调节染色质修饰活性： 生化重建，以及通过多水平染色质的综合分析 转导的癌细胞和内源性 Utx 编辑的 ESC 中的活性。 目标 2. 确定 UTX 冷凝物的生物物理特性如何调节其 生物活性。我们将研究 UTX WT 和变体缩合物的生物物理特性 及其相关的共激活剂。我们将确定凝结水特性对生物的影响 在转导的癌细胞和内源性 Utx 编辑的 ESC 中具有不同水平的活性。 我们还将研究与疾病相关的 UTX 错义突变对冷凝物的影响 特性。