Mechanistic Insights into m6A-Mediated Regulation of Brain Development

摘要 N6-甲基腺苷，或m6 A，是一种高度丰富的碱基修饰，最近显示存在于 成千上万的细胞mRNA。该标记的许多功能作用由m6 A结合蛋白执行， 或“阅读器”，其结合m6 A残基并有助于mRNA调控的各个方面，包括mRNA 输出、稳定性和翻译。催化m6 A形成的甲基转移酶的消耗 已被证明破坏干细胞增殖和分化，并导致发育缺陷。在 在m6 A特别丰富的大脑中，m6 A缺失已被证明会破坏神经发生并引起 严重的神经发育异常。然而，m6 A调节基因的机制 控制神经发育过程的表达知之甚少。此外，介导蛋白质 m6 A在发育中的大脑中的功能尚未被探索。在这里，我们将研究以前的功能 m6 A结合蛋白在大脑发育过程中的作用首先，我们将揭示决定 m6 A结合特异性。第二，我们将利用m6 A耗尽的神经元细胞系与转录组范围的 RNA结合研究，以揭示该阅读器通过m6 A靶向的细胞mRNA。三是 使用全局基因表达谱分析和基因靶向方法的组合来确定 m6 A：读者互动有助于基因表达变化和神经发育。总的来说，这些 研究将描述大脑中一种新的m6 A阅读器的特征，并将提供重要的机制洞察， m6 A调节大脑发育。

ABSTRACT N6-methyladenosine, or m6A, is a highly abundant base modification which was recently shown to be present in thousands of cellular mRNAs. Many of the functional roles of this mark are carried out by m6A-binding proteins, or “readers”, which bind m6A residues and contribute to various aspects of mRNA regulation, including mRNA export, stability, and translation. Depletion of the methyltransferase enzymes that catalyze m6A formation has been shown to disrupt stem cell proliferation and differentiation and to lead to developmental defects. In the brain, where m6A is particularly abundant, m6A depletion has been shown to disrupt neurogenesis and cause severe neurodevelopmental abnormalities. However, the mechanisms through which m6A regulates gene expression to control neurodevelopmental processes are poorly understood. In addition, the proteins mediating m6A function in the developing brain have not been explored. Here, we will investigate the function of a previously unknown m6A binding protein during brain development. First, we will uncover the key features that determine m6A binding specificity. Second, we will utilize m6A-depleted neuronal cell lines coupled with transcriptome-wide RNA binding studies to uncover the cellular mRNAs that are targeted by this reader through m6A. Third, we will use a combination of global gene expression profiling and gene targeting approaches to determine how m6A:reader interactions contribute to gene expression changes and neurodevelopment. Collectively, these studies will characterize a novel m6A reader in the brain and will provide important mechanistic insight into how m6A regulates brain development.