Role of ATAD3A in Lysosomal Homeostasis and Neurogenesis

ATAD3A 在溶酶体稳态和神经发生中的作用

基本信息

批准号：
10413855
负责人：
Wan Hee Yoon
金额：
$ 43.33万
依托单位：
OKLAHOMA MEDICAL RESEARCH FOUNDATION
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10413855
关键词：
Affect Affinity Binding Biogenesis Brain Cells Complex Defect Development Disease Disease model Docking Dominant-Negative Mutation Drosophila genus Embryo Excision Exhibits FRAP1 gene Family Functional disorder Gene Expression Genes Goals Guanosine Triphosphate Guanosine Triphosphate Phosphohydrolases Health Homeostasis Human Induced pluripotent stem cell derived neurons Lead Lysosomes Mediating Metabolic Metabolism Mitochondria Mitochondrial Membrane Protein Modeling Molecular Morphology Mutation Neurologic Neurons Nuclear Optic Atrophy Organoids Pathway interactions Patients Pattern Peripheral Peripheral Nervous System Diseases Plant Roots Play Positioning Attribute Proteins Regulation Role Signal Transduction Syndrome Testing Work base brain malformation brain size early onset experimental study fly gene correction induced pluripotent stem cell insight loss of function mutation lysosomal proteins mitochondrial membrane mutant nervous system disorder neurogenesis neuron development novel null mutation nutrition overexpression protein expression reduce symptoms therapeutic target transcription factor wasting

Affect Affinity Binding Biogenesis Brain Cells Complex Defect Development Disease Disease model Docking Dominant-Negative Mutation Drosophila genus Embryo Excision Exhibits FRAP1 gene Family Functional disorder Gene Expression Genes Goals Guanosine Triphosphate Guanosine Triphosphate Phosphohydrolases Health Homeostasis Human Induced pluripotent stem cell derived neurons Lead Lysosomes Mediating Metabolic Metabolism Mitochondria Mitochondrial Membrane Protein Modeling Molecular Morphology Mutation Neurologic Neurons Nuclear Optic Atrophy Organoids Pathway interactions Patients Pattern Peripheral Peripheral Nervous System Diseases Plant Roots Play Positioning Attribute Proteins Regulation Role Signal Transduction Syndrome Testing Work base brain malformation brain size early onset experimental study fly gene correction induced pluripotent stem cell insight loss of function mutation lysosomal proteins mitochondrial membrane mutant nervous system disorder neurogenesis neuron development novel null mutation nutrition overexpression protein expression reduce symptoms therapeutic target transcription factor wasting

展开

项目摘要

PROJECT SUMMARY/ABSTRACT ATAD3A (ATP family AAA-domain containing protein 3A) is a mitochondrial membrane protein that is implicated in mitochondrial membrane dynamics. We discovered that dominant mutations in ATAD3A cause a human neurological syndrome characterized by early-onset peripheral neuropathy, optic atrophy and mild brain malformation. Patients with loss of function mutations in ATAD3A continue to be identified, presenting with severe neurodevelopmental defects, supporting the importance of this protein in human health. However, the root cause of this syndrome at the cellular and molecular levels, as well as strategies to ameliorate the symptoms remain unsolved issues. Our long-term goal is to determine the roles of ATAD3A in development and in metabolic homeostasis as the basis for therapies to treat patients suffering from ATAD3A-associated diseases. The objective of our proposal is to uncover the mechanisms by which ATAD3A controls nutrition sensing (i.e. mTORC1), lysosomal biogenesis and neuronal development using Drosophila and ATAD3A patient-derived induced pluripotent stem cells. Our Central Hypothesis is that ATAD3A plays a key role in mTORC1 signaling and lysosomal biogenesis through Rag GTPase modulation, and that ATAD3A-dependent nutrition sensing and lysosomal homeostasis are required for proper neurogenesis and development based on the following compelling evidence. Briefly, using IP-mass spec and co-IP, we identified endogenous binding partners of ATAD3A, including the lysosomal proteins RagD, a GTPase required for activating mTORC1, and MiT-TFE proteins, transcriptional factors for lysosomal biogenesis. We found that ATAD3A forms a complex with active Rag GTPases and MiT-TFE proteins. This finding helped explain our discovery that Drosophila bearing a dominant negative ATAD3A mutation (R528W) exhibit defects in nutrition sensing (implicating Rag/mTORC1), and aberrantly elevated lysosomal content in developing neurons (implicating MITF). In Drosophila, we found that ATAD3A null mutations caused embryonic lethality with abnormal patterning and morphology of central and peripheral neurons. In addition, we found that the sizes of brain organoids derived from the patient iPSCs are significantly smaller than those derived from isogenic controls. We will test our central hypothesis by performing the following Specific Aims: (1) to determine how ATAD3A regulates mTORC1 signaling; (2) to determine how ATAD3A mutations lead to abnormal lysosomal biogenesis in neurons; (3) to determine how ATAD3A loss causes neurogenesis defects. These studies will characterize a novel axis of mitochondria-lysosomal-mTORC1 signaling that should reveal novel molecular insights into the cellular defects in patient neurons that underlie ATAD3A-associated neurological diseases. We anticipate the identification of potential therapeutic targets for neurological diseases associated not only with ATAD3A mutations, but also with defects in mitochondrial and lysosomal homeostasis.

项目摘要/摘要 ATAD3A（含有蛋白3a的ATP家族AAA域）是一种线粒体膜蛋白在线粒体膜动力学中。我们发现ATAD3A中的主要突变导致人类神经系统综合征的特征是早发神经病，视神经萎缩和轻度大脑畸形。在ATAD3A中继续识别功能突变损失的患者继续被鉴定出来，并提出严重的神经发育缺陷，支持该蛋白在人类健康中的重要性。但是，该综合征在细胞和分子水平上的根本原因，以及改善症状的策略仍然没有解决问题。我们的长期目标是确定ATAD3A在开发和代谢稳态中的作用作为治疗患有ATAD3A相关疾病患者的疗法的基础。我们的目标建议是揭示ATAD3A控制营养感测（即MTORC1），溶酶体的机制使用果蝇和ATAD3A患者衍生的多能茎的生物发生和神经元发育细胞。我们的中心假设是ATAD3A在MTORC1信号和溶酶体生物发生中起关键作用通过RAG GTPase调制，以及依赖ATAD3A的营养感和溶酶体稳态根据以下令人信服的证据，需要进行适当的神经发生和发育。简要地，使用IP-MAS规格和Co-IP，我们确定了ATAD3A的内源性结合伙伴，包括溶酶体蛋白质RAGD，激活MTORC1所需的GTPase和MIT-TFE蛋白，转录因子的转录因子溶酶体生物发生。我们发现ATAD3A与活性抹布GTPases和MIT-TFE蛋白形成复合物。这一发现有助于解释我们发现果蝇具有主要的负ATAD3A突变（R528W）在营养感测（含有抹布/mTORC1）和异常升高的溶酶体中表现出缺陷开发神经元的内容（暗示MITF）。在果蝇中，我们发现ATAD3A无效突变引起胚胎致死性，具有异常的图案和中央和周围神经元的形态。另外，我们发现从患者IPSC中得出的脑器官的大小明显小于衍生的大小来自等源控制。我们将通过执行以下特定目的来检验中心假设：（1）确定ATAD3A如何调节MTORC1信号传导；（2）确定ATAD3A突变如何导致神经元中的溶酶体生物发生异常；（3）确定ATAD3A损失如何导致神经发生缺陷。这些研究将表征一个新的线粒体 - 溶质体MTORC1信号传导的轴揭示了针对与ATAD3A相关的患者神经元中细胞缺陷的新分子见解神经疾病。我们预计会鉴定神经疾病的潜在治疗靶点不仅与ATAD3A突变有关，还与线粒体和溶酶体稳态中的缺陷有关。