Intracellular repair of oxidation-damaged α-synuclein fails to target C-terminal modification sites.
Intracellular repair of oxidation-damaged α-synuclein fails to target C-terminal modification sites.
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DOI：
10.1038/ncomms10251
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发表时间：
2016-01-25
影响因子：
16.6
通讯作者：
Selenko P
中科院分区：
文献类型：
--
作者：
Binolfi A;Limatola A;Verzini S;Kosten J;Theillet FX;Rose HM;Bekei B;Stuiver M;van Rossum M;Selenko P
细胞氧化应激是许多神经退行性疾病（包括帕金森病）的共同特征。在这里，我们使用细胞内核磁共振光谱研究的命运的氧化损伤帕金森氏病蛋白α-突触核蛋白（α-Syn）在非神经元和神经元哺乳动物细胞。具体来说，我们将蛋氨酸氧化的同位素富集的α-Syn递送到培养的细胞中，并通过内源性酶以原子分辨率跟踪细胞内蛋白质修复。我们发现，N-末端α-Syn蛋氨酸Met 1和Met 5是以逐步的方式处理的，Met 5在Met 1之前被专门修复。相比之下，C-末端蛋氨酸Met 116和Met 127保持氧化，不被细胞酶靶向。反过来，α-Syn C-末端的持续氧化损伤减少了Fyn激酶对Tyr 125的磷酸化，这消除了CK 1修饰Ser 129所必需的引发事件。这些结果表明，氧化应激可导致细胞中化学和功能改变的α-Syn积累。 α-突触核蛋白是一种与帕金森病发生有关的蛋白质。在这里，作者使用时间分辨的细胞内NMR光谱来研究内源性细胞酶对甲硫氨酸氧化的α-突触核蛋白的修复。
Cellular oxidative stress serves as a common denominator in many neurodegenerative disorders, including Parkinson's disease. Here we use in-cell NMR spectroscopy to study the fate of the oxidation-damaged Parkinson's disease protein alpha-synuclein (α-Syn) in non-neuronal and neuronal mammalian cells. Specifically, we deliver methionine-oxidized, isotope-enriched α-Syn into cultured cells and follow intracellular protein repair by endogenous enzymes at atomic resolution. We show that N-terminal α-Syn methionines Met1 and Met5 are processed in a stepwise manner, with Met5 being exclusively repaired before Met1. By contrast, C-terminal methionines Met116 and Met127 remain oxidized and are not targeted by cellular enzymes. In turn, persisting oxidative damage in the C-terminus of α-Syn diminishes phosphorylation of Tyr125 by Fyn kinase, which ablates the necessary priming event for Ser129 modification by CK1. These results establish that oxidative stress can lead to the accumulation of chemically and functionally altered α-Syn in cells. α-synuclein is a protein linked to the occurrence of Parkinson's disease. Here, the authors use time-resolved in-cell NMR spectroscopy to study the repair of methionine-oxidized α-synuclein by endogenous cellular enzymes.