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.

总结： 基因组结构，特别是粘着蛋白介导的增强子-启动子（E-P）环，是基因组形成的关键步骤。 增强子激活和基因转录。在很大程度上仍然不清楚染色质调节因子， 在增强子和启动子处局部发挥作用，影响长距离E-P环。BAF染色质重塑 复合物利用ATP水解产生的能量调节转录，从而调节染色质的附加量 和局部染色质环境。黏连蛋白复合物形成环状结构以介导染色体 组织，包括E-P循环，在G 0/G1阶段。BAF和粘附素的基因突变 亚基与神经发育障碍有关， 症状有相似之处 活动- 调节基因（ARG）表达在短期神经反应以及长期神经反应中起着重要作用。 记忆的形成，自我平衡和适应。在对神经元激活的反应中，粘附素介导的E-P 相互作用要么重新形成，要么变得更强，这是增强子激活和ARG的关键步骤。 表情然而，目前还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BRG 1是BAF复合物中的核心ATP酶亚基，在调节BAF蛋白表达中起着重要作用。 增强子活性，我们确定了一个磷酸化事件，微调BRG 1的功能， 神经刺激我们发现，BRG 1缺失以及BRG 1磷酸化突变导致受损的 增强子激活和E-P环响应神经元活动。目前还不清楚当地的运作方式 染色质重塑物调节粘附素结合和长程E-P环。最近，一个重要的 调节粘着蛋白与增强子结合的机制是粘着蛋白与染色质的结合迁移率。黏结蛋白 释放因子WAPL维持动态粘附素库，这是粘附素与增强子结合所必需的 和谱系特异性基因的表达。我们在HeLa细胞和原代细胞中进行了初步研究， 神经元，并观察到BRG 1在调节粘附素动力学和调节神经元中具有类似的功能。 粘着蛋白在染色质上的全局分布。BRG 1缺失导致粘附素结合的全球增加 染色质，但矛盾的减少，其结合特定的增强子和启动子。BRG 1增强WAPL BRG 1基因的缺失会损害粘附素的动力学。由于BAF复合体可以使用 ATP水解产生的能量，不仅可以提高DNA结合组蛋白的迁移率， 蛋白质，包括本身和PRC 1复合物，它也可以动员染色质结合的cohesin。我们假设 BRG 1及其磷酸化可以促进神经元活动诱导的粘附素动力学， 染色质上的再分布和粘着蛋白介导的E-P环。使用BRG 1和粘附素突变小鼠和新的 利用全基因组技术，我们将研究BRG 1如何调节粘附素染色质分布，以及粘附素如何 调节BRG 1依赖的神经元ARG激活。我们将确定染色质的重要功能 重塑因子和基因组结构调节因子在神经元基因活化和脑疾病中的作用。