A novel functional interaction between a chromatin remodeler and cohesin in neuronal activity-induced enhancer architecture

神经元活动诱导的增强子结构中染色质重塑剂和粘连蛋白之间的新型功能相互作用

• 批准号: 10537687
• 负责人: Jiang Wu
• 金额: $ 45.1万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10537687
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Affect; Architecture; Binding; Brain; Brain Diseases; Chromatin; Chromatin Remodeling Factor; Chromosome Structures; Complex; DNA Binding; DNA Sequence Alteration; Disease; Enhancers; Environment; Event; Foundations; Future; G1 Phase; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Germ Lines; Hela Cells; Histones; Homeostasis; Human; Impairment; Knockout Mice; Link; Mediating; Mental disorders; Methods; Molecular Genetics; Mutant Strains Mice; Mutation; Neurons; PRC1 Protein; Pathology; Pathway interactions; Phosphorylation; Play; Proteins; Reporting; Role; SMARCA4 gene; Solid; Stimulus; Structure; Symptoms; Techniques; chromatin remodeling; cohesin; conditional knockout; developmental disease; epigenetic regulation; genome-wide; improved mobility; long term memory; neurodevelopment; novel; promoter; relating to nervous system; release factor; response; tool

Summary: Genome architecture, especially cohesin-mediated enhancer-promoter (E-P) looping, is a critical step for enhancer activation and gene transcription. It remains largely unknown how chromatin regulators, which often function locally at enhancers and promoters, affect long range E-P looping. BAF chromatin remodeling complexes regulate transcription using energy derived from ATP hydrolysis to modulate chromatin accessibilities and the local chromatin environment. Cohesin complexes form a ring-like structure to mediate chromosome organization, including E-P looping, during the G0/G1 phase. Genetic mutations in both BAF and cohesin subunits are associated with neural developmental disorders, which share similarities in symptoms. Activity- regulated gene (ARG) expression plays an essential role in short-term neural responses as well as in long-term memory formation, homeostasis, and adaptation. In response to neuronal activation, cohesin-mediated E-P interactions either form de novo or become strengthened, a critical step in enhancer activation and ARG expression. However, it remains unclear how neuronal activities promote cohesin function in enhancer activation. Recently, we reported that BRG1, a core ATPase subunit in BAF complexes, plays a central role in regulating enhancer activities, and we identified a phosphorylation event that fine-tunes BRG1 function in response to neuronal stimulation. We showed that BRG1 deletion as well as BRG1 phospho-mutations led to impaired enhancer activation and E-P looping in response to neuronal activities. It remains unclear how locally functioning chromatin remodelers regulate cohesin binding and long-range E-P looping. A recently revealed important mechanism regulating cohesin binding to enhancers is the binding mobility of cohesin to chromatin. The cohesin release factor WAPL maintains a pool of dynamic cohesin, which is required for cohesin binding to enhancers and the expression of lineage-specific genes. We performed preliminary studies in HeLa cells and in primary neurons and observed that BRG1 had a similar function in regulating cohesin dynamics and in regulating the global distribution of cohesin on chromatin. BRG1 deletion led to a global increase in cohesin binding to chromatin but a paradoxical decrease in its binding to specific enhancers and promoters. BRG1 enhanced WAPL function in cohesin release, and BRG1 deletion impaired cohesin dynamics. Since the BAF complex can use the energy derived from ATP hydrolysis to improve the mobility of not only DNA bound histones, but also other proteins including itself and the PRC1 complex, it could also mobilize chromatin-bound cohesin. We hypothesize that BRG1 and its phosphorylation could promote neuronal activity-induced cohesin dynamics, cohesin global redistribution on chromatin, and cohesin-mediated E-P looping. Using BRG1 and cohesin mutant mice and novel genome-wide techniques, we will study how BRG1 regulates cohesin chromatin distribution and how cohesin regulates BRG1-dependent neuronal ARG activation. We will determine the important functions of chromatin remodeling factors and genome architecture regulators in neuronal gene activation and brain disorders.

摘要： 基因组结构，特别是粘附素介导的增强子-启动子(E-P)环是 增强子激活和基因转录。在很大程度上仍不清楚染色质调节器是如何 在增强剂和促进剂中发挥局部作用，影响远程E-P循环。BaF染色质重塑 复合体通过ATP水解产生的能量调节染色质的可及性来调节转录 以及当地的染色质环境。粘附素复合体形成环状结构以调节染色体 组织，包括E-P循环，在G0/G1阶段。BAF和粘附素的基因突变 亚单位与神经发育障碍有关，这是 症状有相似之处。 练习- 调节基因(Arg)的表达在短期神经反应和长期神经反应中都起着重要作用。 记忆形成、动态平衡和适应。粘附素介导的E-P对神经元激活的反应 相互作用要么从头开始，要么加强，这是增强子激活和ARG的关键步骤 表情。然而，目前尚不清楚神经元活动如何促进增强子激活中的粘附素功能。 最近，我们报道了BAF复合体中一个核心的ATPase亚基BRG1在调控中起着中心作用 增强子活性，我们确定了一种磷酸化事件，该事件微调BRG1的功能 神经刺激。我们发现BRG1缺失和BRG1磷酸化突变都会导致基因受损 神经元活动反应中的增强子激活和E-P循环。目前尚不清楚当地如何发挥作用 染色质重构体调节粘附素结合和长距离E-P环。最近披露的一项重要的 调节粘附素与增强剂结合的机制是粘附素与染色质结合的流动性。凝聚力 释放因子WAPL维持着一个动态粘附素池，这是粘附素与增强剂结合所必需的 以及特定血统基因的表达。我们在HeLa细胞和原代细胞中进行了初步研究 并观察到BRG1在调节粘附素动力学和调节 染色质上粘附素的全球分布。BRG1缺失导致粘附素结合的全球增加 染色质与特定的增强子和启动子的结合出现矛盾的减少。BRG1增强型WAPL 在粘附素释放中的作用，BRG1缺失会损害粘附素的动力学。由于BAF综合体可以使用 来自ATP水解的能量，不仅提高了DNA结合的组蛋白的流动性，而且还提高了其他 蛋白质，包括自身和Prc1复合体，它还可以动员染色质结合的粘附素。我们假设 BRG1及其磷酸化可促进神经元活性诱导的粘附素动力学，粘附素全局 染色质上的重分布，以及粘附素介导的E-P环。利用BRG1和粘附素突变小鼠及新 全基因组技术，我们将研究BRG1如何调节粘附素染色质分布以及如何粘附素 调节依赖BRG1的神经元ARG的激活。我们将确定染色质的重要功能 神经基因激活和脑功能障碍中的重塑因子和基因组结构调节因子。