The DJ-1L166P mutant protein associated with early onset Parkinson's disease is unstable and forms higher-order protein complexes
The DJ-1L166P mutant protein associated with early onset Parkinson's disease is unstable and forms higher-order protein complexes
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DOI：
10.1093/hmg/ddg304
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发表时间：
2003-11-01
影响因子：
3.5
通讯作者：
Rizzu, P
中科院分区：
文献类型：
--
作者：
Macedo, MG;Anar, B;Rizzu, P
帕金森病（PD）是一种常见的神经退行性疾病，涉及中脑多巴胺能神经元的选择性变性。最近，在两个欧洲家庭中，DJ-1突变与常染色体隐性早发性帕金森病有关。通过生理条件下的凝胶过滤实验，我们证明了DJ-1蛋白形成二聚体结构。相反，DJ-1（L166P）突变蛋白与DJ-1（WT）相比，在过表达细胞系统或淋巴母细胞中都显示出不同的洗脱谱，表明它可能形成更高阶的蛋白结构。此外，我们观察到患者淋巴细胞中DJ-1（L166P）突变蛋白的水平与野生型蛋白相比非常低。我们通过对患者的材料进行定量RT-PCR，排除了潜在的转录损伤。在转染的COS-1细胞中进行的脉冲追踪实验以及在对照组和患者淋巴母细胞中进行环己亚胺处理表明，突变蛋白被迅速降解。DJ-1（L166P）突变蛋白的这种快速转换和结构变化可能在疾病发病机制中至关重要。
Parkinson's disease (PD) is a common neurodegenerative disorder that involves the selective degeneration of midbrain dopaminergic neurons. Recently DJ-1 mutations have been linked to autosomal-recessive early-onset Parkinsonism in two European families. By using gel filtration assays under physiological conditions we demonstrate that DJ-1 protein forms a dimeric structure. Conversely, the DJ-1(L166P) mutant protein shows a different elution profile as compared with DJ-1(WT) both in overexpression cellular systems or in lymphoblasts cells, suggesting that it might form higher order protein structures. Furthermore we observed that the level of DJ-1(L166P) mutant protein in the patient's lymphoblasts was very low as compared with the wild-type protein. We excluded a potential transcriptional impairment by performing quantitative RT-PCR on the patient's material. Pulse-chase experiments in transfected COS-1 cells and cycloheximide treatment in control and patient lymphoblasts indicated that the mutant protein was rapidly degraded. This rapid turnover and the structural changes of DJ-1(L166P) mutant protein might be crucial in the disease pathogenesis.