Phosphorylation of Ser-129 is the dominant pathological modification of α-synuclein in familial and sporadic Lewy body disease
Phosphorylation of Ser-129 is the dominant pathological modification of α-synuclein in familial and sporadic Lewy body disease
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DOI：
10.1074/jbc.m600933200
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发表时间：
2006-10-06
影响因子：
4.8
通讯作者：
Chilcote, Tamie J.
中科院分区：
文献类型：
--
作者：
Anderson, John P.;Walker, Donald E.;Chilcote, Tamie J.
使用二维免疫印迹分析、使用修饰特异性突触核蛋白抗体的新型夹心酶联免疫吸附测定和质谱法，对路易体痴呆患者的路易体中存在的突触核蛋白形式进行了全面、公正的清查。路易体中 α-突触核蛋白的主要修饰是 Ser-129 处的单磷酸化。此外，还有一组较小程度存在的特征性修饰，包括 Lys 残基 12、21 和 23 处的泛素化以及 Asp-115、Asp-119、Asn-122、Tyr-133 和 Asp-135 处的特异性截短。除了普遍存在的 N 末端外，通过串联质谱图谱无法检测到其他修饰乙酰化。少量Ser-129磷酸化和Asp-119截短的α-突触核蛋白存在于正常和患病大脑的可溶部分中，表明这些路易体相关形式是在α-突触核蛋白的正常代谢过程中产生的。相比之下，泛素化仅在路易体中检测到，并且主要存在于磷酸化突触核蛋白上；因此，它很可能发生在磷酸化突触核蛋白沉积到路易体中之后。这种特定磷酸化、截短和泛素化的不变模式也存在于家族性帕金森病（突触核蛋白 A53T 突变）以及多系统萎缩患者大脑的去污剂不溶性部分中，表明遗传性和散发性路易体病存在共同的致病途径。这些观察结果与以下模型最为一致：正常产生的Ser-129磷酸化α-突触核蛋白的优先积累是导致各种路易体疾病中路易体形成的关键事件。
A comprehensive, unbiased inventory of synuclein forms present in Lewy bodies from patients with dementia with Lewy bodies was carried out using two- dimensional immunoblot analysis, novel sandwich enzyme- linked immunosorbent assays with modification- specific synuclein antibodies, and mass spectroscopy. The predominant modification of alpha-synuclein in Lewy bodies is a single phosphorylation at Ser-129. In addition, there is a set of characteristic modifications that are present to a lesser extent, including ubiquitination at Lys residues 12, 21, and 23 and specific truncations at Asp- 115, Asp- 119, Asn-122, Tyr- 133, and Asp- 135. No other modifications are detectable by tandem mass spectrometry mapping, except for a ubiquitous N- terminal acetylation. Small amounts of Ser- 129 phosphorylated and Asp- 119- truncated alpha- synuclein are present in the soluble fraction of both normal and disease brains, suggesting that these Lewy body-associated forms are produced during normal metabolism of alpha-synuclein. In contrast, ubiquitination is only detected in Lewy bodies and is primarily present on phosphorylated synuclein; it therefore likely occurs after phosphorylated synuclein has deposited into Lewy bodies. This invariant pattern of specific phosphorylation, truncation, and ubiquitination is also present in the detergent- insoluble fraction of brain from patients with familial Parkinson's disease ( synuclein A53T mutation) as well as multiple system atrophy, suggesting a common pathogenic pathway for both genetic and sporadic Lewy body diseases. These observations are most consistent with a model in which preferential accumulation of normally produced Ser- 129 phosphorylated alpha- synuclein is the key event responsible for the formation of Lewy bodies in various Lewy body diseases.