Division of Toxicology and Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow 226031, India.
Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India.
Cells. 2022 Nov 25;11(23):3770. doi: 10.3390/cells11233770.
Protein aggregation is one of the major pathological events in age-related Parkinson's disease (PD) pathology, predominantly regulated by the ubiquitin-proteasome system (UPS). UPS essentially requires core component ubiquitin; however, its role in PD pathology is obscure. This study aimed to investigate the role of ubiquitin-encoding genes in sporadic PD pathology. Both cellular and rat models of PD as well as SNCA C57BL/6J-Tg (Th-SNCAA30PA53T)39 Eric/J transgenic mice showed a decreased abundance of UBA52 in conjunction with significant downregulation of tyrosine hydroxylase (TH) and neuronal death. In silico predictions, mass spectrometric analysis, and co-immunoprecipitation findings suggested the protein-protein interaction of UBA52 with α-synuclein, HSP90 and E3-ubiquitin ligase CHIP, and its co-localization with α-synuclein in the mitochondrion. Next, in vitro ubiquitylation assay indicated an imperative requirement of the lysine-63 residue of UBA52 in CHIP-mediated HSP90 ubiquitylation. Myc-UBA52 expressed neurons inhibited alteration in PD-specific markers such as α-synuclein and TH protein along with increased proteasome activity in diseased conditions. Furthermore, Myc-UBA52 expression inhibited the altered protein abundance of HSP90 and its various client proteins, HSP75 (homolog of HSP90 in mitochondrion) and ER stress-related markers during early PD. Taken together, the data highlights the critical role of UBA52 in HSP90 ubiquitylation in parallel to its potential contribution to the modulation of various disease-related neurodegenerative signaling targets during the early phase of PD pathology.
蛋白质聚集是与年龄相关的帕金森病（PD）病理学中的主要病理事件之一，主要受泛素-蛋白酶体系统（UPS）调节。UPS 本质上需要核心成分泛素；然而，其在 PD 病理学中的作用尚不清楚。本研究旨在研究泛素编码基因在散发性 PD 病理学中的作用。PD 的细胞和大鼠模型以及 SNCA C57BL/6J-Tg（Th-SNCAA30PA53T）39Eric/J 转基因小鼠均显示 UBA52 的丰度降低，同时酪氨酸羟化酶（TH）和神经元死亡显著下调。计算机预测、质谱分析和共免疫沉淀结果表明 UBA52 与 α-突触核蛋白、热休克蛋白 90（HSP90）和 E3-泛素连接酶 CHIP 的蛋白-蛋白相互作用及其与 α-突触核蛋白在线粒体中的共定位。接下来，体外泛素化测定表明 UBA52 的赖氨酸-63 残基在 CHIP 介导的 HSP90 泛素化中是必需的。在疾病状态下，表达 Myc-UBA52 的神经元抑制 PD 特异性标志物（如 α-突触核蛋白和 TH 蛋白）的改变以及蛋白酶体活性的增加。此外，Myc-UBA52 表达抑制 HSP90 及其各种客户蛋白（HSP75（线粒体中的 HSP90 同源物）和与 ER 应激相关的标志物）在早期 PD 期间的改变的蛋白丰度。总之，数据强调了 UBA52 在 HSP90 泛素化中的关键作用，以及其在 PD 病理学早期阶段调节各种与疾病相关的神经退行性信号靶标方面的潜在贡献。
