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

项目总结/摘要 核DNA上的生物过程发生在染色质的背景下。转录的精确调节， DNA复制和DNA损伤修复需要染色质协调的组蛋白迁移的动态控制 调控神经发育中染色质调控的多重作用正在被揭开。最近的研究 已经揭示了细胞命运的规范，神经可塑性和电路的形成，部分介导的， 染色质从机制上讲，染色质通过转录组调控来调节这些发育过程。 然而，染色质在基因组维护中也起着重要作用。基因组完整性尤其重要 在快速分裂的干细胞，包括神经祖细胞（NPC）中起重要作用。DNA复制和DSB修复 每一个都发生在染色质的背景下，染色质必须为DNA上的所有交易进行重组，包括 复制叉进展、DSB检测和DNA修复因子的募集。这些过程 由染色质重塑-ATP依赖性蛋白复合物介导， 从DNA中驱逐核小体，或交换组蛋白亚基，从而控制可接近性，灵活性， 和染色质的流动性。与众所周知的染色质的转录作用形成鲜明对比的是， 染色质调节在基因组维持中的重要功能在神经系统中几乎未被探索。 发展在这里，所提出的工作建立在我们最近关于染色质重塑剂Ino80的论文（Keil等人， 2020），其中我们发现Ino80在YY 1相关转录调控和同源 皮质NPC中的重组（HR）DNA修复。值得注意的是，受损的DNA修复是神经解剖学的驱动力。 Ino80缺失后的表型，从而证明了染色质的这种未被探索的作用可以影响 神经发育的后果重要的是，Ino80的DNA修复功能在染色质中并不独特。 重塑者在这个应用中，我们试图研究DNA中染色质重塑的潜在更广泛的作用， NPC的伤害和修复。我们将运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）解剖转录调控中不同的染色质重塑功能， 基因组维持; 2）确定DNA复制中染色质重塑功能的机制， 损伤修复;和3）评估染色质重塑功能障碍的脑体细胞基因组后果。 最近的人类遗传学研究结果表明，在神经发育过程中， 紊乱在这里，我们提出，除了转录调控，染色质重塑发挥同样的作用， 在NPC分裂的基因组稳定性中起重要作用。染色质功能的这一方面在很大程度上是未探索的 在大脑发育中。我们的研究将解决这一领域的重要差距，并从机制上剖析不同的 染色质重塑在转录调控中的作用与神经发育中的基因组维持。

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.