Deubiquitinase USP19 in TDP-43 pathogenesis.

RNA结合核蛋白TDP-43错误定位于细胞质，并在细胞内聚集。 额颞叶变性（FTLD-TDP变体），肌萎缩侧索硬化症（ALS）， 和>50%的晚发性阿尔茨海默病（AD）。异常TDP-43错误定位和 蓄积与内质网（ER）应激、突触功能障碍和 认知和运动障碍虽然TDP-43经历不同的翻译后 修饰，包括磷酸化，聚ADP-核糖基化，氧化，乙酰化， 泛素化是周转所需的最后关键修饰 TDP-43通过泛素-蛋白酶体系统和自噬-溶酶体途径。TDP-43是 由E3连接酶Parkin、PJA 1和Znf 179泛素化。然而，去泛素化酶的作用 （DUBs）在TDP-43功能、转换、蛋白质病和毒性的调节中的作用较差 明白人类基因组编码约90个DUB。泛素特异性肽酶（USP）是 DUB的最大家族，在人类中包含约50个成员。其中，27个是在 CNS。我们对CNS表达的DUB进行无偏筛选的结果将USP 19鉴定为 主要的TDP-43 DUB，TDP-43稳定性的正调节剂，并且是进一步研究的有希望的候选者。 study.具体而言，初步研究表明，USP 19，一种DUB在衰老过程中升高， FTLD-TDP患者的脑，起到增加TDP-43稳定性/聚集的作用，并参与 TDP-43诱导的ER应激。 利用小鼠模型和人死后组织， 细胞生物学，成像，生物化学，蛋白质组学，电生理学，行为，病毒， 组织化学和重组蛋白工具集，该建议将1。验证USP的作用19 在TDP-43发病机制和相关表型体内，和2。确定机制基础 USP 19在TDP-43去泛素化、稳定性、聚集和毒性中的作用 神经元和体外系统。 这些研究的成功结论将确定USP 19的重要贡献， 其DUB活性对人和小鼠中TDP-43发病机制的影响。此外，这些结果将提供 在ER应激中USP 19 DUB活性与TDP-43一致的新机制见解， 神经毒性总之，这些研究将使追求一个潜在的治疗方向， 靶向USP 19介导的机制，以减轻TDP-43的病理学和毒性。

The RNA-binding nuclear protein TDP-43 mislocalizes to the cytoplasm and aggregates in Frontotemporal lobar degeneration (FTLD-TDP variant), Amyotrophic Lateral Sclerosis (ALS), and >50% of late-onset Alzheimer’s disease (AD). Abnormal TDP-43 mislocalization and accumulation is associated with endoplasmic reticulum (ER) stress, synaptic dysfunction, and cognitive and motor impairments. While TDP-43 undergoes different post-translational modifications including phosphorylation, poly ADP-ribosylation, oxidation, acetylation, sumoylation, and ubiquitination, ubiquitination is a final key modification required for the turnover of TDP-43 via the ubiquitin-proteasome system and autophagy-lysosome pathways. TDP-43 is ubiquitinated by E3 ligases Parkin, PJA1, and Znf179. However, the role of deubiquitinases (DUBs) in the regulation of TDP-43 function, turnover, proteinopathy, and toxicity is poorly understood. The human genome encodes ~90 DUBs. Ubiquitin specific peptidases (USPs) are the largest family of DUBs comprising ~50 members in humans. Of these, 27 are expressed in the CNS. Our results from an unbiased screen of CNS-expressed DUBs identified USP19 as a major TDP-43 DUB, a positive regulator of TDP-43 stability, and a promising candidate for further study. Specifically, preliminary studies indicate that USP19, a DUB elevated during aging and in brains of FTLD-TDP patients, acts to increase TDP-43 stability/aggregation and participates in TDP-43-induced ER stress. By taking advantage of mouse models and human postmortem tissues together with molecular, cell biological, imaging, biochemical, proteomics, electrophysiological, behavioral, viral, histochemical, and recombinant protein toolsets, this proposal will 1. validate the role of USP19 in TDP-43 pathogenesis and associated phenotypes vivo, and 2. determine the mechanistic basis of USP19 in TDP-43 deubiquitination, stability, aggregation, and toxicity in genetically modified neurons and in vitro systems. Successful conclusion of these studies will determine the significant contribution of USP19 and its DUB activity to TDP-43 pathogenesis in humans and mice. Moreover, these results will provide novel mechanistic insights to USP19 DUB activity in concert with TDP-43 in ER stress and neurotoxicity. Together, these studies will enable the pursuit of a potential therapeutic direction of targeting USP19-mediated mechanisms to mitigate TDP-43 pathology and toxicity.