Elucidating the Roles of Mbd3 during Cerebellar Development

染色质重塑复合物是单亚基或多亚基蛋白质复合物，被认为是调节细胞凋亡的蛋白质。 通过改变基因组沿着核小体的组成、占据或定位来调节转录。许多 染色质重塑复合物亚单位的突变与智力残疾和自闭症有关， 这表明神经元可能需要严格的染色质调节来建立神经元连接。因此，我们认为， 了解染色质重塑如何调节电路的发展是至关重要的， 这些神经发育障碍。 与许多其他染色质重塑复合物一样，核小体重塑亚单位的突变和 脱乙酰酶（NuRD）复合物与智力残疾和自闭症有关。在染色质中独一无二 然而，NuRD复合物被赋予两种酶：染色质重塑酶， ATP酶和组蛋白脱乙酰酶，分别通过Chd 3/4和Hdac 1/2。此前， 实验室发现，Chd 4是建立小脑颗粒神经元与小脑的连接所必需的。 小脑皮层的回路chd 4调节树突的消除和 颗粒神经元发育过程中的突触前终扣。这些观察结果提出了一个至关重要的问题， NuRD复合功能导致颗粒神经元连接。 各种支架亚基被认为调节复合物的功能，但只有Mbd 3是必需的。 复杂的装配。初步证据表明，Mbd 3控制Chd 4的一个子集的转录。 依赖基因在小脑，可能通过调节Chd 4功能直接在这些网站。澄清 Mbd 3如何调节神经元连接，本提案将定义Mbd 3在（1）颗粒神经元中的作用 与体内电穿孔和成像方法的连接性;和（2）Chd 4依赖性转录， 染色质免疫沉淀（ChIP）-seq和生物信息学分析。 阐明这些机制将有助于深入了解Mbd 3在NuRD复合物功能中的作用， 大脑发育，阐明神经发育障碍的潜在机制。

Chromatin remodeling complexes are single- or multi-subunit protein complexes that are thought to regulate transcription by modifying the composition, occupancy, or positioning of nucleosomes along the genome. Many mutations in chromatin remodeling complex subunits are associated with intellectual disability and autism, suggesting that neurons may require strict chromatin regulation to establish neuronal connectivity. Therefore, understanding how chromatin remodeling regulates circuit development is crucial to discovering treatments for these neurodevelopmental disorders. Like many other chromatin remodeling complexes, mutations in subunits of the nucleosome remodeling and deacetylase (NuRD) complex are associated with intellectual disability and autism. Unique among chromatin remodeling complexes though, the NuRD complex is endowed with two enzymes: a chromatin remodeling ATPase and a histone deacetylase, through Chd3/4 and Hdac1/2, respectively. Previously, the Bonni laboratory discovered that Chd4 is required to establish connectivity of the cerebellar granule neuron into the circuit of the cerebellar cortex. Chd4 regulates both the elimination of dendrites and the formation of presynaptic boutons during granule neuron development. These observations raise vital questions about how NuRD complex function leads to granule neuron connectivity. Various scaffold subunits are thought to regulate the function of the complex, but only Mbd3 is required for complex assembly. Preliminary evidence suggests that Mbd3 controls transcription of a subset of Chd4- dependent genes in the cerebellum, potentially by regulating Chd4 function directly at these sites. To clarify how Mbd3 regulates neuronal connectivity, this proposal will define roles for Mbd3 in (1) granule neuron connectivity with in vivo electroporation and imaging approaches; and (2) Chd4-dependent transcription with chromatin immunoprecipitation (ChIP)-seq and bioinformatic analyses. Clarifying these mechanisms will develop fundamental insight into Mbd3’s role in NuRD complex function and brain development, illuminating potential mechanisms of neurodevelopmental disorder.