Insights into Gordon Holmes syndrome by substrate profiling of Triad3A and Chip using Orthogonal Ubiquitin Transfer

使用正交泛素转移对 Triad3A 和 Chip 进行底物分析，深入了解 Gordon Holmes 综合征

• 批准号: 10218866
• 负责人: Angela M Mabb
• 金额: $ 42.88万
• 依托单位: GEORGIA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2023-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10218866
• 关键词: Alzheimer' s Disease; Angelman Syndrome; Biological Assay; Brain; Brain region; Cell membrane; Cell physiology; Cells; Cullin Proteins; Data; Defect; Dementia; Dendritic Spines; Dependovirus; Development; Disease; Engineering; Enzymes; Exhibits; Functional disorder; Genes; Goals; Gonadotropin Hormone Releasing Hormone; Hippocampus (Brain); Human; Human Genome; Huntington Disease; Hypothalamic dysfunction; Hypothalamic structure; Individual; Inflammation; Inherited; Intellectual functioning disability; Klinefelter' s Syndrome; Knockout Mice; Knowledge; Lead; Lentivirus; Link; Location; Maps; Mediating; Molecular; Molecular Target; Mus; Mutate; Mutation; Nerve Degeneration; Nervous system structure; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neurologic; Neurons; Outcome; Parkinson Disease; Pathologic; Pathway interactions; Patients; Phenotype; Physiological; Positioning Attribute; Precipitating Factors; Protein Isoforms; Proteins; Proteomics; Quality Control; Reaction; Reversal Learning; Role; Signal Pathway; Signal Transduction; Specific qualifier value; Substrate Specificity; Synapses; Synaptic plasticity; Syndrome; UBE3A gene; Ubiquitin; Ubiquitin-Activating Enzymes; Ubiquitin-Conjugating Enzymes; Ubiquitination; Work; autism spectrum disorder; brain tissue; cohort; density; innovation; insight; nervous system disorder; neurodevelopment; neuron development; neuropathology; neurophysiology; neurotransmitter release; parkin gene/protein; programs; protein protein interaction; receptor; synergism; trafficking; ubiquitin ligase; ubiquitin-protein ligase

Abstract: In the nervous system, protein ubiquitination subserves multiple cellular processes, utilizing an enzymatic cascade that consists of ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2), and ubiquitin ligases (E3). The main function of the E3 in this pathway is to covalently link a small 76 residue protein called ubiquitin on to selected protein targets known as substrates. It is estimated that E3s represent 500 – 1000 genes in the human genome. We found 83 different E3s that are mutated in 70 different types of neurological disease providing supporting evidence that disruptions in ubiquitin signaling is a precipitating factor in human neurological conditions. Although a multitude of E3s are mutated in numerous neurological disorders, there is still a paucity of knowledge regarding the function and substrates of disease- relevant E3s in the brain. In this proposal, we will elucidate key functions for two E3s, TRIAD3A and CHIP, which are mutated in a heterogenous neurological disorder called Gordon Holmes syndrome (GHS). Major pathophysiologies of GHS include hypothalamic dysfunction, dementia and neurodegeneration. Individuals with RNF216/TRIAD3 and CHIP/STUB1 mutations also exhibit hypogonadotropic hypogonadism, which is thought to be caused by a dysfunctional hypothalamic-pitiutary-gonadal (HPG) axis due to deficiencies in the release of gonadotropin- releasing hormone (GnRH) within GnRH positive neurons in the hypothalamus. Here, we hypothesize that the brain-expressed isoform of RNF216/TRIAD3, TRIAD3A and CHIP regulate a suite of substrates, whose ubiquitination gives rise to the diversity of phenotypes observed in GHS. In Aim 1, we will develop a ubiquitin substrate capture platform known as “Orthogonal Ubiquitin Transfer” to profile the substrate specificities of TRIAD3A and CHIP in hippocampal neurons. In Aim 2, we will verify the synergy between TRIAD3A and CHIP in neuron development. Taken together, our study will provide the first comprehensive overview of brain-specific TRIAD3A and CHIP substrates that alter physiological functions in select brain regions, and will identify new molecular targets to compensate for the deficiency of these two enzymes in GHS patients. More broadly, our work will provide a mechanistic perspective of how malfunctions of E3s cause neurological diseases. By identifying common substrate profiles for TRIAD3A and CHIP, we will be able to reveal key mechanistic deficiencies associated with GHS, which may ultimately be effective in guiding the treatment of GHS and similar neurodegenerative diseases.

翻译后摘要：在神经系统中，蛋白质泛素化subserves多个细胞过程， 利用由泛素活化酶（E1）、泛素 缀合酶（E2）和泛素连接酶（E3）。E3在这一通路中的主要功能是 是将一种称为泛素的76个残基的小蛋白质共价连接到已知的选定蛋白质靶点上， 作为底物。据估计，E3代表人类基因组中的500 - 1000个基因。我们 在70种不同类型的神经系统疾病中发现了83种不同的E3突变， 支持证据表明，在泛素信号中断是一个诱发因素，在人类 神经系统疾病尽管在许多神经系统中， 尽管存在疾病，但仍然缺乏关于疾病的功能和基质的知识- 大脑中相关的E3在这个提议中，我们将阐明两个E3的关键功能，TRIAD 3A 和CHIP，它们在一种名为Gordon Holmes的异质性神经系统疾病中发生突变 综合征（GHS）。GHS的主要病理生理学包括下丘脑功能障碍、痴呆 和神经退化携带RNF 216/TRIAD 3和CHIP/STUB 1突变的个体也 表现出低促性腺激素性腺功能减退症，这被认为是由功能障碍引起的。 下丘脑-垂体-性腺（HPG）轴由于促性腺激素释放不足， 下丘脑GnRH阳性神经元内的促性腺激素释放激素（GnRH）。这里我们 假设RNF 216/TRIAD 3、TRIAD 3A和CHIP的脑表达同种型调节 一套底物，其泛素化引起了观察到的表型的多样性， GHS。在目标1中，我们将开发一个被称为“正交”的泛素底物捕获平台， 泛素转移”来分析海马中TRIAD 3A和CHIP的底物特异性 神经元在目标2中，我们将验证TRIAD 3A和CHIP在神经元发育中的协同作用。 综上所述，我们的研究将首次全面概述脑特异性TRIAD 3A 和CHIP底物，改变选择的大脑区域的生理功能，并将识别新的 分子靶点来弥补GHS患者中这两种酶的缺乏。更 概括地说，我们的工作将提供一个关于E3故障如何导致 神经系统疾病通过识别TRIAD 3A和CHIP的共同底物谱，我们将 能够揭示与全球统一制度相关的关键机制缺陷，这可能最终被 有效指导GHS和类似神经退行性疾病的治疗。