Defining the neuronal function of the polyadenosine RNA-binding protein ZC3H14

定义聚腺苷 RNA 结合蛋白 ZC3H14 的神经元功能

• 批准号: 8786299
• 负责人: Kevin J. Jamal Morris
• 金额: $ 4.27万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2017-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8786299
• 关键词: Adaptive Behaviors; Affinity; Antibodies; Axon; Biological Assay; Brain; Cell Line; Cell physiology; Cells; Child; Complement; Complex; Coupled; Data; Defect; Dendrites; Detection; Disabled Persons; Disease; Drosophila genus; Ensure; Event; Fragile X Mental Retardation Protein; Fragile X Syndrome; Functional disorder; Gene Expression; Gene Expression Regulation; Genes; Genetic Translation; Goals; Hippocampus (Brain); Human; Impairment; Individual; Inherited; Intellectual functioning disability; Knock-out; Knockout Mice; Lead; Length; Link; Mass Spectrum Analysis; Mental Retardation; Metabolism; Methods; Modeling; Molecular; Mus; Mutation; Neurites; Neurons; Nuclear; Patients; Phenotype; Play; Poly(A) Tail; Population; Positioning Attribute; Protein Binding; Protein Biosynthesis; Proteins; RNA; RNA-Binding Proteins; Regulation; Reporting; Ribonucleases; Ribosomes; Role; SCA2 protein; Saccharomycetales; Small Interfering RNA; System; Testing; Transcript; Translations; Work; Zinc Fingers; base; brain tissue; cell type; cognitive function; dFMR1 gene; fly; handicapping condition; insight; mutant; neuroblastoma cell; novel; polyadenosine; public health relevance; research study; young adult

DESCRIPTION (provided by applicant): Intellectual disability, previously termed mental retardation, is a disorder characterized by a significant delay in cognitive function and limitatios in adaptive behaviors. Although the causes of intellectual disability are highly heterogeneous, genetic defects that underlie some occurrences of inherited intellectual disability have begun to be identified. Among the genes linked to intellectual disability, genes encoding RNA- binding proteins have been implicated in a number of cases, including the most common form of inherited intellectual disability, Fragile X Syndrome. Recently, our group reported inactivating mutations in the ZC3H14 gene, which encodes an evolutionarily conserved, ubiquitously expressed polyadenosine RNA-binding protein, ZC3H14. Despite ubiquitous expression of the ZC3H14 protein, the patients with mutant ZC3H14 display non- syndromic, intellectual disability where only brain function is impaired. This finding suggests that ZC3H14 has a critical, specialized role in the brain. Studies in Drosophila reveal a key role specifically in neurons. A major difference between neurons and many other cell types is the need for highly regulated and localized translational control particularly in the neurite extensions. While the steady-state localization of ZC3H14 is nuclear, our recent studies reveal that a population of ZC3H14 is present in axons of primary hippocampal neurons. In addition, we also find that ZC3H14 associates with 80S ribosomes. These results suggest a cytoplasmic role for ZC3H14 that is similar to that of other RNA-binding proteins that regulate translation. Indeed, preliminary studies in Drosophila have identified functional interactions between the Drosophila orthologue of ZC3H14 and Drosophila orthologues of two other RNA-binding proteins that regulate translation Fragile X Mental Retardation Protein (FMRP) and Ataxin-2. As both FMRP and Ataxin-2 regulate translation, these functional interactions suggest that ZC3H14 could also modulate translation. Given our preliminary findings, we hypothesize that ZC3H14 works cooperatively with specific RNA regulatory factors to ensure local translation in neurons. In this proposal, we test our hypothesis by investigating the molecular functions of ZC3H14 through the following complementary aims. In Aim 1, we assess the requirement for ZC3H14 in regulating translation by manipulating levels of ZC3H14 and examining protein synthesis, moving from global approaches to more targeted approaches. In Aim 2, we will test for physical interactions between ZC3H14 and candidate translation regulators. These studies will exploit a ZC3H14 knockout mouse we have recently developed, providing an optimal system to assess the functional and molecular consequences of loss of ZC3H14. The broad long-term goal is to provide insight into how ZC3H14, along with other interacting proteins, influences post-transcriptional events and ensures proper higher order brain function. Understanding the function of ZC3H14 is a critical step in elucidating the complex roles of RNA-binding proteins in controlling spatial and temporal regulation of gene expression.

描述（由申请人提供）：智力障碍，以前称为精神发育迟滞，是一种以认知功能显着延迟和适应性行为限制为特征的疾病。尽管智力障碍的原因具有很大的异质性，但某些遗传性智力障碍的遗传缺陷已经开始被发现。在与智力障碍相关的基因中，编码 RNA 结合蛋白的基因与许多病例有关，包括最常见的遗传性智力障碍——脆性 X 综合征。最近，我们的小组报告了 ZC3H14 基因的失活突变，该基因编码一种进化上保守的、普遍表达的多腺苷 RNA 结合蛋白 ZC3H14。尽管ZC3H14蛋白普遍表达，但具有突变ZC3H14的患者表现出非综合征性智力障碍，其中仅大脑功能受损。这一发现表明 ZC3H14 在大脑中具有关键的、特殊的作用。对果蝇的研究揭示了其在神经元中的关键作用。神经元和许多其他细胞类型之间的主要区别是需要高度调节和局部翻译控制，特别是在神经突延伸中。虽然 ZC3H14 的稳态定位是核，但我们最近的研究表明 ZC3H14 群体存在于初级海马神经元的轴突中。此外，我们还发现ZC3H14与80S核糖体结合。这些结果表明 ZC3H14 的细胞质作用与其他调节翻译的 RNA 结合蛋白的作用相似。事实上，果蝇的初步研究已经确定了 ZC3H14 的果蝇直系同源物与调节脆性 X 智力迟钝蛋白 (FMRP) 和 Ataxin-2 翻译的其他两种 RNA 结合蛋白的果蝇直系同源物之间的功能相互作用。由于 FMRP 和 Ataxin-2 都调节翻译，这些功能相互作用表明 ZC3H14 也可以调节翻译。根据我们的初步发现，我们假设 ZC3H14 与特定的 RNA 调节因子协同作用，以确保神经元中的局部翻译。在本提案中，我们通过以下互补目标研究 ZC3H14 的分子功能来检验我们的假设。在目标 1 中，我们通过操纵 ZC3H14 的水平和检查蛋白质合成来评估 ZC3H14 在调节翻译方面的要求，从全局方法转向更有针对性的方法。在目标 2 中，我们将测试 ZC3H14 和候选翻译调节因子之间的物理相互作用。这些研究将利用我们最近开发的 ZC3H14 敲除小鼠，提供一个最佳系统来评估 ZC3H14 缺失的功能和分子后果。广泛的长期目标是深入了解 ZC3H14 与其他相互作用的蛋白质如何影响转录后事件并确保适当的高阶大脑功能。了解 ZC3H14 的功能是阐明 RNA 结合蛋白在控制基因表达的空间和时间调控中的复杂作用的关键一步。