Dopamine-mediated oxidation of methionine 127 in α-synuclein causes cytotoxicity and oligomerization of α-synuclein.
Dopamine-mediated oxidation of methionine 127 in α-synuclein causes cytotoxicity and oligomerization of α-synuclein.
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DOI：
10.1371/journal.pone.0055068
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Matsura T
中科院分区：
文献类型：
--
作者：
Nakaso K;Tajima N;Ito S;Teraoka M;Yamashita A;Horikoshi Y;Kikuchi D;Mochida S;Nakashima K;Matsura T
帕金森病(Parkinson‘s Disease，PD)是一种以多巴胺能神经元选择性丢失和路易体存在为特征的神经退行性疾病。近年来的研究主要集中在α-突触核蛋白(α-SYN)与多巴胺在帕金森病发病机制中的相互作用，荧光各向异性提示α-SYN的C末端区域可能是多巴胺修饰的靶点。然而，为什么帕金森病相关的发病机制选择性地发生在多巴胺能神经元中还不是很清楚。我们从细胞毒性的角度研究了多巴胺和α-SYN之间的相互作用。α-SYN与多巴胺体外共孵育形成可溶性齐聚物。为了阐明多巴胺对细胞内α-SYN的影响，我们以四环素诱导的方式建立了表达人α-SYN的PC12细胞以及α-SYN突变体M116A、Y125D、M127A、S129A和M116A/M127A(PC12-TetOFF-α-SYN)。在儿茶酚胺能PC12细胞中过表达野生型α-SYN会降低细胞在长期培养中的存活率，而酪氨酸羟化酶的竞争性抑制剂可以阻断这一脆弱性，这表明α-SYN相关的细胞毒性与多巴胺代谢有关。所有突变细胞系的脆弱性均低于野生型α-SYN表达细胞。此外，在pC12-α-α-SYN中检测到含有多巴胺介导的氧化蛋氨酸(Met(O))的DNA-SYN。Met(O)在蛋氨酸突变细胞中较低，特别是在M127A或M116A/M127A突变细胞中，在Y125D和S129A突变细胞中也是如此。多巴胺和125YEMPS129肽的共同孵育促进了过氧化氢的产生，过氧化氢可能氧化蛋氨酸残基并将其转化为甲硫氨酸(O)。缺少Y125或S129的多肽不会增加多巴胺相关的过氧化氢的产生。我们的结果表明，M127是多巴胺氧化修饰的主要靶点，而Y125和S129可能是这种修饰的增强子。这些结果可能描述了α-SYN的多巴胺能神经元特异性毒性在帕金森病发病机制中的作用。
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the selective loss of dopaminergic neurons and the presence of Lewy bodies. Many recent studies focused on the interaction between α-synuclein (α-syn) and dopamine in the pathogenesis of PD, and fluorescent anisotropy suggested that the C-terminal region of α-syn may be a target for modification by dopamine. However, it is not well understood why PD-related pathogenesis occurs selectively in dopaminergic neurons. We investigated the interaction between dopamine and α-syn with regard to cytotoxicity. A soluble oligomer was formed by co-incubating α-syn and dopamine in vitro. To clarify the effect of dopamine on α-syn in cells, we generated PC12 cells expressing human α-syn, as well as the α-syn mutants, M116A, Y125D, M127A, S129A, and M116A/M127A, in a tetracycline-inducible manner (PC12-TetOFF-α-syn). Overexpression of wildtype α-syn in catecholaminergic PC12 cells decreased cell viability in long-term cultures, while a competitive inhibitor of tyrosine hydroxylase blocked this vulnerability, suggesting that α-syn-related cytotoxicity is associated with dopamine metabolism. The vulnerabilities of all mutant cell lines were lower than that of wildtype α-syn-expressing cells. Moreover, α-syn containing dopamine-mediated oxidized methionine (Met(O)) was detected in PC12-TetOFF-α-syn. Met(O) was lower in methionine mutant cells, especially in the M127A or M116A/M127A mutants, but also in the Y125D and S129A mutants. Co-incubation of dopamine and the 125YEMPS129 peptide enhanced the production of H2O2, which may oxidize methionine residues and convert them to Met(O). Y125- or S129-lacking peptides did not enhance the dopamine-related production of H2O2. Our results suggest that M127 is the major target for oxidative modification by dopamine, and that Y125 and S129 may act as enhancers of this modification. These results may describe a mechanism of dopaminergic neuron-specific toxicity of α-syn in the pathogenesis of PD.
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影响因子：
3.9
作者：
Nuytemans, Karen;Theuns, Jessie;Cruts, Marc;Van Broeckhoven, Christine
通讯作者：
Van Broeckhoven, Christine
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168.9
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通讯作者：
Lansbury, PT
影响因子：
168.9
作者：
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