Enhancer activation mechanisms in cranial neural crest osteoblast differentiation

项目摘要 增强子在启动和维持细胞特异性转录程序的表达方面起着至关重要的作用。一个 增强子激活和基因调控的关键特征是改变局部染色质状态以促进结合 转录协同调节因子对增强子。与增强剂相关的染色质修饰酶 在人类头面部疾病中，功能通常发生突变，包括组蛋白甲基酶，去甲基酶， 乙酰酶、染色质阅读器和染色质重塑蛋白。许多这些染色质修饰因子 生物化学关联并可能共同调节神经内的增强子和转录激活事件 冠状突起是一种干细胞，面部的前部骨骼和软骨都是由其衍生而来的。我们已经建立了几个这样的模型 组织特异性敲除小鼠神经中的染色质修饰因子引起的人类颅面部疾病 冠状细胞。本提案中概述的实验将通过以下方式表征从头开始的增强子激活 成骨细胞分化过程中原代颅神经脊细胞染色质的变化。神经脊细胞 缺乏染色质修饰机制的人将被分子分析以破坏增强子染色质 并确定这些因素之间的协同作用。这项提案将结合使用 以生物化学、遗传学和低细胞数基因组学方法阐明染色质的作用 增强子激活在颅面部疾病发病机制中的作用。

Project Summary Enhancers play a vital role in initiating and maintaining expression of cell specific transcriptional programs. A key feature in enhancer activation and gene regulation is changing the local chromatin state to facilitate binding of transcriptional co-regulators to enhancers. Chromatin-modifying enzymes that are associated with enhancer function are commonly mutated in human craniofacial disorders including histone methylases, demethylases, acetylases, chromatin readers, and chromatin remodeling proteins. Many of these chromatin-modifying factors biochemically associate and may co-regulate enhancer and transcriptional activation events within neural crest, stem cells from which anterior facial bone and cartilage are derived. We have modeled several of these human craniofacial disorders through tissue specific knockout of chromatin-modifying factors in mouse neural crest cells. The experiments outlined in this proposal will characterize de novo enhancer activation by chromatin profiling of primary cranial neural crest cells undergoing osteoblast differentiation. Neural crest cells deficient in chromatin-modifying machinery will be analyzed molecularly for disruption of enhancer chromatin states and to identify cooperative functions between these factors. This proposal will utilize a combination of biochemical, genetic, and low cell number genomic approaches to elucidate the role of chromatin-based enhancer activation in craniofacial disorder pathogenesis.