Roles of the methylase NSD3 in neural crest migration and non-histone methylation

项目摘要/摘要： 神经脊细胞，一种脊椎动物胚胎特有的多潜能干细胞样群，迁移速度很快 发育过程中的距离，以形成各种不同类型的细胞，包括头面部软骨和 骨骼、黑素细胞、肾上腺髓质和许多周围神经系统。神经脊的缺陷 细胞迁移导致颅面疾病，如口面部裂隙，以及由此产生的神经脊失调。 细胞类型导致许多浸润性癌症，如神经母细胞瘤。GamMill实验室最近的工作 确认NSD3是第一个赖氨酸甲基转移酶，对神经脊基因的表达和 迁移。虽然已知NSD3的作用是对组蛋白H3的第36个赖氨酸残基进行二甲基化，但组蛋白H3的耗竭 NSD3不会显著改变H3K36me2在神经脊基因上的占有率，即使这些基因 不再表达。这些结果以及NSD3在迁移神经脊中的胞浆定位 细胞，细胞质蛋白甲基化在神经脊迁移过程中的重要性，以及越来越多的证据 组蛋白甲基转移酶可以甲基化额外的非组蛋白蛋白，这导致了一种假设 NSD3甲基化非组蛋白靶标，以调节神经脊细胞迁移和基因表达。至 探索这一假说，这一建议旨在定义NSD3在细胞迁移过程中的重要作用 NSD3非组蛋白靶标及其调控的迁移特性在鸡胚胎培养和移植中的应用 通过它们的甲基化作用。这将通过(1)定义迁移的具体方面来实现，这些方面包括 NSD3基因敲除细胞中的缺陷，(2)通过质谱仪鉴定NSD3甲基化的非组蛋白 基于光谱的定量蛋白质组学，以及(3)分析NSD3非组蛋白靶点的需求 在迁移过程中，并确定依赖NSD3的甲基化对其功能的重要性。 实现这些目标将定义一种新的调控模式，管理神经脊细胞迁移和 并将揭示NSD3的新功能和新靶点。这些结果将揭示 未被认可的对细胞迁移的翻译后控制，将揭示一种新的调控机制 发展，并将对努力预防头面部出生缺陷和发展具有重要意义 转移的治疗。

PROJECT SUMMERY/ABSTRACT: Neural crest cells, a multipotent stem cell-like population unique to vertebrate embryos, migrate great distances during development to form a wide variety of different cell types including craniofacial cartilage and bone, melanocytes, the adrenal medulla, and much of the peripheral nervous system. Defects in neural crest cell migration result in craniofacial maladies such as orofacial clefts, and dysregulation of neural crest derived cell types leads to a number of invasive cancers such as neuroblastoma. Recent work in the Gammill lab identified NSD3 as the first lysine methyltransferase that is essential for neural crest gene expression and migration. Although the known role of NSD3 is to dimethylate the 36th lysine residue of histone H3, depletion of NSD3 does not significantly alter H3K36me2 occupancy on neural crest genes even though these genes are no longer expressed. These results, as well as the cytoplasmic localization of NSD3 in migrating neural crest cells, the importance of cytoplasmic protein methylation during neural crest migration, and increasing evidence that “histone” methyltransferases can methylate additional non-histone proteins, leads to the hypothesis that NSD3 methylates non-histone targets in order to regulate neural crest cell migration and gene expression. To explore this hypothesis, this proposal aims to define the essential role of NSD3 during cell migration in cell culture and in chick embryos by characterizing NSD3 non-histone targets and the migratory features regulated by their methylation. This will be accomplished by (1) defining the specific aspects of migration that are defective in NSD3 knockdown cells, (2) identifying non-histone proteins methylated by NSD3 through mass spectrometry-based quantitative proteomics, and (3) assaying the requirement for NSD3 non-histone targets during migration, and determining the importance of NSD3-dependent methylation for their function. Accomplishing these goals will define a novel mode of regulation governing neural crest cell migration and craniofacial development, and will reveal new functions and targets of NSD3. These results will reveal unappreciated post-translational control over cell migration, will uncover a novel regulatory mechanism in development, and will have important implications for efforts to prevent craniofacial birth defects and develop treatments for metastasis.