Investigating how nuclear pore components exploit an ER-dependent quality control pathway

研究核孔成分如何利用内质网依赖的质量控制途径

• 批准号: 10678645
• 负责人: Madison Lynn Pletan
• 金额: $ 4.16万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10678645
• 关键词: Amyotrophic Lateral Sclerosis; Autophagocytosis; Cell Culture Techniques; Cell Nucleus; Cell physiology; Cells; Complex; Coupled; Cytoplasm; Cytosol; Data; Disease; Disease Progression; Endoplasmic Reticulum; Event; Frontotemporal Dementia; Goals; Individual; Integral Membrane Protein; Kinesin; Lysosomes; Mammalian Cell; Mediating; Membrane; Modeling; Motor; Motor Neurons; Mus; Muscle Weakness; Muscular Atrophy; Neurodegenerative Disorders; Neurons; Nuclear; Nuclear Envelope; Nuclear Pore; Nuclear Pore Complex; Outcome Study; Paralysed; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Phenotype; Pore Proteins; Process; Proteins; Quality Control; Reporting; Research; Role; Small Interfering RNA; System; Testing; Tissues; Transport Process; Work; age related neurodegeneration; frontotemporal lobar dementia amyotrophic lateral sclerosis; human disease; kinectin; knock-down; loss of function; motor neuron degeneration; muscle strength; novel; nucleocytoplasmic transport; prevent; receptor; receptor binding; recruit; response; trafficking

Abstract Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that primarily targets motor neurons, leading to progressive muscle weakness and paralysis. There is no cure for ALS or the related disorder frontotemporal dementia (FTD), largely because it is unclear which of the many implicated cellular pathways are causative. A growing number of studies have identified damage to the nuclear pore complex (NPC) as a key pathological phenotype in both ALS-diseased tissue and ALS models. This damage is characterized by defective nucleocytoplasmic transport and mislocalization of NPC components (“Nups”) to the cytosol. To examine the fate of mislocalized Nups, our research group has developed a model for NPC disruption whereby we deplete a key structural Nup and track the localization of other Nups. Strikingly, our preliminary data shows that the displaced Nups form aggregates in the endoplasmic reticulum, a process which is dependent on the ER transmembrane protein kinectin. These aggregates accumulate upon depletion of the major autophagy factor Beclin-1, suggesting that the Nups are targeted for ER-coupled autophagy. Together, these findings point to a novel nucleus-to-ER autophagy pathway that may be functioning when Nups are displaced in ALS. Based on this preliminary data, we hypothesize that the cellular motor protein kinesin-1 transports Nups from the nucleus to the ER (Aim 1A), and that this transport process also occurs in a disease-relevant cell culture model (Aim 1B). We further hypothesize that once at the ER, the Nup aggregates are cleared by receptor-mediated autophagy (Aim 2). This work will elucidate basic intracellular trafficking and quality control pathways. More importantly, understanding cellular response to mislocalized Nups may provide a better mechanistic picture of the progression of ALS/FTD.

摘要 肌萎缩侧索硬化症(ALS)是一种主要针对运动的致命性神经退行性疾病。 神经元，导致进行性肌肉无力和瘫痪。肌萎缩侧索硬化症或 相关疾病额颞叶痴呆(FTD)，主要是因为目前还不清楚 牵连的细胞通路是致病因素。越来越多的研究已经确定了对 核孔复合体(NPC)作为ALS病组织和ALS患者的关键病理表型 肌萎缩侧索硬化模型。这种损害的特征是核质转运缺陷和 鼻咽癌成分(“NUP”)在细胞质中的错误定位。 为了研究定位错误的NUP的命运，我们的研究小组开发了一个鼻咽癌模型 破坏，我们消耗一个关键的结构NUP，并跟踪其他NUP的本地化。 值得注意的是，我们的初步数据显示，移位的核仁在内质中形成聚集体。 网状，这是一个依赖于内质网跨膜蛋白动凝素的过程。这些 聚集体在主要的自噬因子Beclin-1耗尽时积累，这表明 核蛋白是内质网偶联自噬的靶标。总而言之，这些发现指向了一种新的核到内质网 在肌萎缩侧索硬化症中，当核子移位时，自噬途径可能起作用。在此基础上 初步数据，我们假设细胞运动蛋白kinesin-1从 细胞核到内质网(目标1A)，这一运输过程也发生在与疾病相关的细胞中 培养模式(目标1B)。我们进一步假设，一旦到达ER，NUP聚集体就被清除 通过受体介导的自噬(目标2)。这项工作将阐明基本的细胞内运输和 质量控制路径。更重要的是，了解细胞对错误定位的NUP的反应 可能为ALS/FTD的进展提供了更好的机制图景。