Investigating the Regulatory Roles of Histone Chaperones in Cellular Plasticity

研究组蛋白伴侣在细胞可塑性中的调节作用

• 批准号: 10714076
• 负责人: Sihem Cheloufi
• 金额: $ 38.88万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10714076
• 关键词: Binding; Biochemical; Cell Fate Control; Cell Proliferation; Cells; Chromatin; Complex; DNA; DNA biosynthesis; Development; Differentiated Gene; Disease; Elements; Enhancers; Genes; Genetic Recombination; Genetic Transcription; Genome; Goals; Health; Heterochromatin; Histones; Link; Maintenance; Molecular; Molecular Chaperones; Nucleosomes; Pathway interactions; Play; Process; Proteins; RNA Interference; Regulation; Research; Research Proposals; Role; Site; Specific qualifier value; Structure-Activity Relationship; Variant; Work; chromatin assembly factor I; design; epigenome; gene repression; multiple omics; new technology; novel therapeutics; prevent; promoter; repaired; stem; stem cells; structural determinants; transcription factor

PROJECT SUMMARY Histone chaperones are functionally and structurally diverse proteins. They play a central role in chromatin organization and maintenance by binding to histones and facilitating nucleosome assembly during DNA replication, transcription, recombination and repair processes. Moreover, some histone chaperones evolved additional functions independent of histone binding. Histone chaperones are thus essential for cellular proliferation and organismal development. Intriguingly, circumventing this lethality in a number of cell fate change paradigms revealed roles of histone chaperones in cellular plasticity. For example, we and others have shown that the chromatin assembly factor 1 (CAF-1), a histone chaperone complex involved in replication dependent nucleosome assembly and heterochromatin regulation, prevents cellular reprogramming. More recently, we demonstrated that CAF-1 maintains lineage integrity of stem and progenitor cells by repressing the transcription of differentiation genes. In this context, CAF-1 controls chromatin accessibility at enhancer/promoter elements of lineage specific loci and prevents aberrant binding of transcription factors. In addition to these CAF-1 sensitive sites, we also identified heterochromatic loci whose accessibility is perturbed upon CAF-1 loss, albeit with unknown effects on cell fate. The influence of CAF-1 on local euchromatic and heterochromatic loci is intriguing given that CAF-1 acts in a sequence independent manner to assemble nucleosomes during DNA replication. Whether such profound effects of CAF-1 on cell fate are linked to its nucleosome assembly function or additional non-canonical functions remain unexplored. Moreover, given the growing repertoire of histone chaperones and associated histone variants, it remains unclear whether CAF-1 cooperates with other histone chaperones to maintain lineage integrity. Therefore, the functional and structural determinants of the histone chaperone network as a whole in the context of cell fate remain important open questions. To investigate the molecular mechanisms underlying the lineage specifying functions of histone chaperones, we will use well established cell fate change paradigms in combination with gene editing/RNAi, multi-omics, biochemical and functional approaches. Specifically, we propose the following two research directions: (1) Investigate the regulatory mechanisms and function of histone chaperone sensitive chromatin sites and, (2) interrogate the structure-function relationships of histone chaperones and how their domains are intimately linked to control cell fate. In the short-term, we plan to dissect the epigenome and structural determinants of CAF-1. In the long-term we plan to extend our analysis to other histone chaperones pathways and how they cooperate with CAF-1 to control cell fate. If successful, our studies will contribute to design strategies for manipulating histone chaperone pathways to control cell fate in health and disease.

项目摘要 组蛋白伴侣在功能和结构上是多样的蛋白质。他们在染色质中起着核心作用 通过与组蛋白结合并促进DNA期间的核小体组装来组织和维护 复制，转录，重组和修复过程。此外，一些组蛋白伴侣进化了 与组蛋白结合无关的其他功能。因此，组蛋白伴侣对于细胞至关重要 扩散和生物发展。有趣的是，在许多细胞命运中绕过这种致命性 变化范式揭示了组蛋白伴侣在细胞可塑性中的作用。例如，我们和其他人有 表明染色质组装因子1（CAF-1），一种参与复制的组蛋白伴侣复合体 依赖性核小体组装和异染色质调节可防止细胞重编程。更多的 最近，我们证明CAF-1通过抑制茎和祖细胞的谱系完整性 分化基因的转录。在这种情况下，CAF-1控制着染色质的可及性 谱系特定基因座的增强子/启动子元素并防止转录因子的异常结合。在 除了这些CAF-1敏感位点，我们还鉴定 CAF-1损失后，尽管对细胞命运有未知的影响。 CAF-1对当地风格和 鉴于CAF-1以独立的方式起作用以组装杂物基因座很有趣 DNA复制过程中的核小体。 CAF-1对细胞命运的影响是否与其命运有关 核小体组装函数或其他非规范功能仍未探索。而且，给定 越来越多的组蛋白伴侣和相关组蛋白变体的曲目尚不清楚CAF-1是否尚不清楚 与其他组蛋白伴侣合作以保持谱系完整性。因此，功能和结构 在细胞命运的背景下，组蛋白伴侣网络的决定因素仍然很重要开放 问题。研究指定组蛋白谱系功能的谱系基础的分子机制 伴侣，我们将使用良好的细胞命运变化范例与基因编辑/RNAi结合使用， 多词，生化和功能性方法。具体来说，我们提出以下两项研究 方向：（1）研究组蛋白伴侣敏感染色质的调节机制和功能 站点和（2）询问组蛋白伴侣的结构功能关系以及它们的域是如何 与控制细胞命运密切相关。在短期内，我们计划剖析表观基因组和结构 CAF-1的决定因素。从长远来看，我们计划将分析扩展到其他组蛋白伴侣途径 以及他们如何与CAF-1合作以控制细胞命运。如果成功，我们的研究将有助于设计 操纵组蛋白伴侣途径以控制健康和疾病中细胞命运的策略。