SPOP modifies neurodegenerative proteinopathy in Alzheimer’s Disease.

项目摘要 聚集的病理性tau蛋白构成阿尔茨海默病（AD）的诊断标志之一， 相关疾病（ADRD）。病理性tau蛋白引起功能障碍的分子机制， 神经元的退化仍然不完全清楚。然而，病理性tau蛋白驱动的神经元功能障碍 和神经退化显然会导致痴呆为了研究病理性tau蛋白如何导致 我们在秀丽隐杆线虫中建立了转基因模型， 由人类tau聚集驱动的神经变性。通过采用经典的前向遗传方法，我们 鉴定了几个基因，其功能丧失抑制tau蛋白病，包括spop-1。SPOP（斑点型 POZ蛋白）是RING E3泛素连接酶Cullin-3（CUL 3）的保守核衔接蛋白，选择性地表达Cullin-3， 在泛素蛋白酶体系统（UPS）中降解的蛋白质。在通过CRISPR产生真正的无效等位基因后， 我们发现spop-1的缺失显著降低了tau蛋白的积累和磷酸化， tau mRNA丰度，挽救寿命，减少神经变性，并改善tau蛋白的行为缺陷 转基因动物 除了其在UPS活性中的作用之外，SPOP还经历液-液相分离（LLPS），定位于 核散斑（NS）。我们以前在C. elegans和AD神经元表明NS功能中断 和组合物导致tau毒性。值得注意的是，spop-1的缺失也拯救了C9 orf 72二肽重复序列 毒性为C.遗传性肌萎缩侧索硬化症（ALS）和额颞叶的elegans模型 变性（FTLD）。我们的初步结果表明spop-1的缺失抑制了C. elegans 表达ALS连锁突变体TDP-43以及共表达TDP-43和tau的转基因，其重新计算 AD和ADRD相关的相互作用。 总之，我们的工作使我们假设SPOP作为蛋白质病的多功能调节剂， AD和ADRD。我们假设SPOP-CUL 3 UPS活性和SPOP LLPS/NS定位有助于 tau蛋白病的潜在机制为了调查这些假设，该项目的具体目标是： 具体目的：（1）表征AD/ADRD神经退行性蛋白病中SPOP功能丧失， (2)确定SPOP功能丧失抑制tau蛋白病的机制，以及（3）评估 SPOP在阿尔茨海默病中的翻译相关性。 通过完成拟议的工作，我们将揭示疾病机制的新分子理解 包括SPOP蛋白-以及核斑点和Cullin-3 -如何参与tau蛋白病和相关疾病， ADRD共病。这项工作也将提供深入了解SPOP在阿尔茨海默氏症中的翻译相关性。 疾病的大脑，为未来的研究奠定基础，并为新疗法的发展提供信息。

PROJECT SUMMARY Aggregated pathological tau protein constitutes one of the diagnostic hallmarks of Alzheimer’s disease (AD) and related disorders (ADRD). The molecular mechanisms by which pathological tau causes dysfunction and degeneration of neurons remain incompletely understood. However, pathological tau driven neuronal dysfunction and neurodegeneration clearly cause dementia. To investigate how pathological tau contributes to neurodegeneration in AD and ADRDs, we established a transgenic model in Caenorhabditis elegans for neurodegeneration driven by human tau aggregation. By employing classical forward genetic approaches, we identified several genes whose loss of function suppresses tauopathy, including spop-1. SPOP (speckle-type POZ protein) is a conserved nuclear adaptor protein for the RING E3 ubiquitin ligase Cullin-3 (CUL3), selecting proteins for degradation in the ubiquitin proteasome system (UPS). After generating a true null allele via CRISPR- cas9, we found that loss of spop-1 dramatically decreases tau accumulation and phosphorylation without altering tau mRNA abundance, rescues lifespan, reduces neurodegeneration, and improves behavioral deficits in tau transgenic animals. In addition to its role in UPS activity, SPOP also undergoes liquid-liquid phase separation (LLPS) localizing to nuclear speckles (NS). Our previously work in C. elegans and AD neurons indicate disruptions to NS function and composition contribute to tau toxicity. Remarkably, loss of spop-1 also rescues C9orf72 dipeptide-repeat toxicity in a C. elegans model of genetic amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Our preliminary results indicate loss of spop-1 suppresses behavioral deficits in C. elegans expressing ALS-linked mutant TDP-43 as well as transgenics co-expressing TDP-43 and tau, which recalculate AD and ADRD relevant interactions. Altogether, our work led us to hypothesize that SPOP functions as a multipurpose regulator of proteinopathy in AD and ADRDs. We hypothesize SPOP-CUL3 UPS activity and SPOP LLPS/NS localization contribute to the underlying mechanisms of tauopathy. To investigate these hypothesizes the specific aims of this project are: SPECIFIC AIMS: (1) Characterize SPOP loss of function in AD/ADRD neurodegenerative proteinopathies, (2) Determine the mechanism by which SPOP loss of function suppresses tauopathy, and (3) Evaluate the translational relevance of SPOP in Alzheimer’s disease. By completing the proposed work, we will uncover new molecular understandings of disease mechanisms including how SPOP protein – as well as nuclear speckles and Cullin-3 – participate in tauopathy and related ADRD co-pathologies. This work will also provide insight into the translational relevance of SPOP in Alzheimer’s disease brains, setting the stage for future study and informing the development of novel therapeutics.