Van Laar Victor S, Mishizen Amanda J, Cascio Michael, Hastings Teresa G
Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Neurobiol Dis. 2009 Jun;34(3):487-500. doi: 10.1016/j.nbd.2009.03.004. Epub 2009 Mar 28.
Dopamine oxidation has been previously demonstrated to cause dysfunction in mitochondrial respiration and membrane permeability, possibly related to covalent modification of critical proteins by the reactive dopamine quinone. However, specific mitochondrial protein targets have not been identified. In this study, we utilized proteomic techniques to identify proteins directly conjugated with (14)C-dopamine from isolated rat brain mitochondria exposed to radiolabeled dopamine quinone (150 microM) and differentiated SH-SY5Y cells treated with (14)C-dopamine (150 microM). We observed a subset of rat brain mitochondrial proteins that were covalently modified by (14)C-dopamine, including chaperonin, ubiquinol-cytochrome c reductase core protein 1, glucose regulated protein 75/mitochondrial HSP70/mortalin, mitofilin, and mitochondrial creatine kinase. We also found the Parkinson's disease associated proteins ubiquitin carboxy-terminal hydrolase L1 and DJ-1 to be covalently modified by dopamine in both brain mitochondrial preparations and SH-SY5Y cells. The susceptibility of the identified proteins to covalent modification by dopamine may carry implications for their role in the vulnerability of dopaminergic neurons in Parkinson's disease pathogenesis.
多巴胺氧化先前已被证明会导致线粒体呼吸和膜通透性功能障碍，这可能与活性多巴胺醌对关键蛋白质的共价修饰有关。然而，具体的线粒体蛋白质靶点尚未确定。在本研究中，我们利用蛋白质组学技术，从暴露于放射性标记多巴胺醌（150微摩尔）的分离大鼠脑线粒体以及用（14）C-多巴胺（150微摩尔）处理的分化型SH-SY5Y细胞中，鉴定与（14）C-多巴胺直接结合的蛋白质。我们观察到大鼠脑线粒体蛋白质的一个子集被（14）C-多巴胺共价修饰，包括伴侣蛋白、泛醇-细胞色素c还原酶核心蛋白1、葡萄糖调节蛋白75/线粒体热休克蛋白70/ mortalin、线粒体融合蛋白和线粒体肌酸激酶。我们还发现帕金森病相关蛋白泛素羧基末端水解酶L1和DJ-1在脑线粒体制剂和SH-SY5Y细胞中均被多巴胺共价修饰。所鉴定蛋白质对多巴胺共价修饰的敏感性可能对它们在帕金森病发病机制中多巴胺能神经元易损性的作用具有影响。
