Mechanistic Insights into m6A-Mediated Regulation of Brain Development

摘要 N6-甲基腺苷，或M6A，是一种高度丰富的碱基修饰，最近被证明存在于 数以千计的细胞mRNA。该标记的许多功能角色由m6A结合蛋白执行， 或“阅读器”，结合m6A残基，参与包括mRNAs在内的多方面的mRNA调控。 输出、稳定和转换。催化M6A形成的甲基转移酶的枯竭已经 已被证明会扰乱干细胞的增殖和分化，并导致发育缺陷。在 大脑中m6A尤其丰富，m6A的枯竭已被证明会扰乱神经发生并导致 严重的神经发育异常。然而，m6A调控基因的机制 控制神经发育过程的表达还知之甚少。此外，介导性蛋白质 M6A在发育中的大脑中的作用还没有被探索过。在这里，我们将研究以前的一个 大脑发育过程中未知的m6A结合蛋白。首先，我们将揭示决定因素的关键特征 M6A结合特异性。第二，我们将利用m6A缺失的神经细胞系与全转录组相结合。 RNA结合研究，以揭示该读者通过m6A靶向的细胞mRNAs。第三，我们将 使用全球基因表达谱和基因靶向方法的组合来确定 M6A：读者互动有助于基因表达的变化和神经发育。总而言之，这些 研究将描述大脑中的小说M6A阅读器的特征，并将提供重要的机械洞察 M6A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.