MeCP2 and non-CG methylation regulation of neuronal cell-type specific transcription

项目概述：转录调节蛋白的突变已被确定为导致 神经发育障碍，如自闭症和智力残疾。为了了解这些蛋白质是如何驱动 疾病病理学，我们需要首先发展一个机制的理解，这些调节剂如何有助于 正常的神经发育甲基-CpG结合蛋白2（MeCP 2）的改变导致Rett综合征 (RTT)一种严重的神经发育障碍，以及一种自闭症谱系的MeCP 2复制综合征 disorder. MeCP 2已显示结合甲基化CG二核苷酸和神经元富集形式的 非CpG背景下胞嘧啶甲基化（mCA）。MeCP 2的缺失导致长链RNA的表达增加。 神经元基因（> 100 kb），在其基因体内富集mCA。有趣的是，mCA和MeCP 2 已显示以细胞类型特异性方式调节基因表达。我们实验室的长期目标是 了解MeCP 2和mCA转录调控在神经系统中的功能，以及它们如何在神经系统中发挥作用。 功能障碍导致神经紊乱。 该提案将确定MeCP 2和mCA如何控制细胞类型特异性基因表达程序 通过控制调控元件并与基因组拓扑学合作。在目标1中，我将测试 MeCP 2调节细胞类型特异性增强子以驱动个体中基因表达程序假设 神经元在目标2中，我将通过分析染色质结构如何 驱动细胞类型特异性mCA模式。这些实验的结果将提供重要的见解， MeCP 2和mCA的机制和功能，以及它们在被破坏时如何产生病理。

Project Summary: Mutations in transcriptional regulatory proteins have been identified as a major cause of neurodevelopmental disorders such as autism and intellectual disability. To understand how these proteins drive disease pathology, we need to first develop a mechanistic understanding of how these regulators contribute to normal neurodevelopment. Alterations in methyl-CpG binding protein 2 (MeCP2) results in Rett Syndrome (RTT), a severe neurodevelopmental disorder, and MeCP2 Duplication Syndrome, an autism spectrum disorder. MeCP2 has been shown to bind both methylated CG dinucleotides and a neuron-enriched form of methylation at cytosines in non-CpG contexts (mCA). Loss of MeCP2 leads to increased expression of long neuronal genes (>100kb) that are enriched for mCA within their gene body. Interestingly, mCA and MeCP2 have been shown to regulate gene expression in a cell-type specific manner. The long-term goal of our lab is to understand the function of MeCP2 and mCA transcriptional regulation in the nervous system and how their dysfunction results in neurological disorders. This proposal will determine how MeCP2 and mCA control cell-type specific gene expression programs through control of regulatory elements and in cooperation with genome topology. In Aim 1, I will test the hypothesis that MeCP2 regulates cell-type specific enhancers to drive gene expression programs in individual neurons. In Aim 2, I will further understand this regulatory mechanism by analyzing how chromatin architecture drives cell-type specific mCA patterns. The results from these experiments will provide important insights into the mechanism and function of MeCP2 and mCA and how they produce pathology when disrupted.