Distinct roles of chromatin regulation in transcriptome and genome maintenance in corticogenesis

项目摘要/摘要 核DNA上的生物过程发生在染色质的背景下。转录的精确调控， DNA复制和DNA损伤修复需要动态控制染色质协调的组蛋白迁移率 监管。染色质调节在神经发育中的多重作用正在被解开。最新研究 揭示了细胞命运指定、神经可塑性和电路形成在一定程度上是由 染色质。从机制上讲，染色质通过转录调控来调节这些发育过程。 然而，染色质在基因组维持中也扮演着重要的角色。基因组完整性尤其是 对包括神经前体细胞在内的干细胞的快速分裂非常重要。DNA复制与DSB修复 每一种都发生在染色质的背景下，必须为DNA上的所有交易重新组织染色质，包括 复制分叉进程、DSB检测和DNA修复因子的招募。这些过程是 染色质重构体--一种依赖于ATP的蛋白质复合体，可将核小体重新定位于 DNA，驱逐DNA中的核小体，或交换组蛋白亚基，从而控制可获得性，灵活性， 和染色质的流动性。与众所周知的染色质转录作用形成鲜明对比的是，同样 染色质调节在基因组维持中的重要作用在神经学中几乎是未知的 发展。在这里，拟议的工作建立在我们最近关于染色质重构体INO80(Keil等人， 2020)，其中我们发现INO80在YY1相关的转录调控和同源基因中可分离的作用 皮质神经干细胞中的重组(HR)DNA修复。值得注意的是，DNA修复受损是神经解剖学的驱动因素 INO80缺失后的表型，从而表明这种未被探索的染色质作用可以影响 神经发育的后果。重要的是，INO80‘S的DNA修复功能在染色质中并不是独一无二的 改造者。在这个应用中，我们试图研究染色质重塑在dna中潜在的更广泛的作用。 Npc中的损坏和修复。我们将应用我们在染色质生物学、DNA损伤修复、功能性 基因组学和遗传学：1)剖析不同的染色质重塑功能在转录调控和 基因组维持；2)确定染色质重塑功能在DNA复制和 损伤修复；以及3)评估染色质重塑功能障碍对脑体细胞基因组的影响。 最近的人类遗传学发现一致地表明染色质失调与神经发育有关。 精神错乱。在这里，我们提出，除了转录调控，染色质重塑也同样起到了 对鼻咽癌各部门基因组稳定性的重要作用。染色质功能的这一方面在很大程度上是未知的 在大脑发育方面。我们的研究将解决该领域的这一重要差距，并机械地剖析不同的 染色质重塑在神经发育中转录调控与基因组维持中的作用。

PROJECT SUMMARY/ABSTRACT Biological processes on nuclear DNA occur in the context of chromatin. The precise regulation of transcription, DNA replication, and DNA damage repair requires dynamic control of histone mobility orchestrated by chromatin regulation. The multiple roles of chromatin regulation in neurodevelopment are being unraveled. Recent studies have revealed that cell fate specification, neural plasticity, and circuit formation are mediated, in part, by chromatin. Mechanistically, chromatin modulates these developmental processes via transcriptomic regulation. Chromatin, however, also plays an essential role in genome maintenance. Genome integrity is particularly important in rapidly dividing stem cells, including neural progenitor cells (NPCs). DNA replication and DSB repair each occur in the context of chromatin, which must be reorganized for all transactions on DNA, including replication fork progression, DSB detection, and recruitment of DNA repair factors. These processes are mediated by chromatin remodelers – ATP-dependent protein complexes that can reposition nucleosomes on DNA, evict nucleosomes from DNA, or exchange histone subunits, thus controlling the accessibility, flexibility, and mobility of chromatin. In striking contrast to the well-known transcriptional roles of chromatin, the equally important functions of chromatin regulation in genome maintenance are virtually unexplored in neural development. Here, the proposed work builds on our recent paper on the chromatin remodeler Ino80 (Keil et al., 2020), in which we find dissociable roles for Ino80 in YY1-associated transcriptional regulation and homologous recombination (HR) DNA repair in cortical NPCs. Notably, impaired DNA repair is the driver of neuroanatomical phenotypes following Ino80 deletion, thus demonstrating that this underexplored role of chromatin can effect neurodevelopmental consequences. Importantly, Ino80’s DNA repair function is not unique among chromatin remodelers. In this application, we seek to investigate a potentially wider role of chromatin remodeling in DNA damage and repair in NPCs. We will apply our expertise in chromatin biology, DNA damage repair, functional genomics, and genetics to: 1) dissect distinct chromatin remodeling functions in transcriptional regulation versus genome maintenance; 2) determine the mechanisms of chromatin remodeling functions in DNA replication and damage repair; and 3) assess the brain somatic genome consequences of chromatin remodeling dysfunction. Recent human genetic findings have convergently implicated chromatin dysregulation in neurodevelopmental disorders. Here, we propose that, in addition to transcriptional regulation, chromatin remodeling plays an equally important role in genome stability across NPC divisions. This aspect of chromatin function is largely unexplored in brain development. Our study will address this important gap in the field and mechanistically dissect the distinct roles of chromatin remodeling in transcriptional regulation versus genome maintenance in neurodevelopment.