Copper-induced structural conversion templates prion protein oligomerization and neurotoxicity.
Copper-induced structural conversion templates prion protein oligomerization and neurotoxicity.
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DOI：
10.1126/sciadv.1600014
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发表时间：
2016-07
期刊：
影响因子：
13.6
通讯作者：
Sivasankar S
中科院分区：
文献类型：
--
作者：
Yen CF;Harischandra DS;Kanthasamy A;Sivasankar S
铜诱导朊蛋白错误折叠、聚集和神经毒性。朊蛋白（PrP）的错误折叠和寡聚化是朊病毒病的关键致病事件。铜暴露与朊病毒发病机制有关；然而，其机制基础尚不清楚。我们以单分子精度解决了生理条件下Cu2+诱导PrP错误折叠的分子机制。我们还证明，错误折叠的PrPs作为模板聚集体形成的种子，介导炎症和神经元组织变性。利用单分子荧光分析，我们证明Cu2+诱导PrP单体在低聚物组装前发生错误折叠；无序的氨基末端区域介导了这种结构变化。单分子力谱测量表明，与天然异构体相比，错误折叠的单体具有高900倍的结合亲和力，这促进了它们的寡聚化。实时震动诱导的转化表明，错误折叠的PrPs作为模板淀粉样蛋白形成的种子。最后，器官型切片培养显示，错误折叠的PrPs介导了神经元组织的炎症和变性。我们的研究在分子水平上建立了铜暴露与PrP神经毒性之间的直接联系。
Copper induces prion protein misfolding, aggregation, and neurotoxicity. Prion protein (PrP) misfolding and oligomerization are key pathogenic events in prion disease. Copper exposure has been linked to prion pathogenesis; however, its mechanistic basis is unknown. We resolve, with single-molecule precision, the molecular mechanism of Cu2+-induced misfolding of PrP under physiological conditions. We also demonstrate that misfolded PrPs serve as seeds for templated formation of aggregates, which mediate inflammation and degeneration of neuronal tissue. Using a single-molecule fluorescence assay, we demonstrate that Cu2+ induces PrP monomers to misfold before oligomer assembly; the disordered amino-terminal region mediates this structural change. Single-molecule force spectroscopy measurements show that the misfolded monomers have a 900-fold higher binding affinity compared to the native isoform, which promotes their oligomerization. Real-time quaking-induced conversion demonstrates that misfolded PrPs serve as seeds that template amyloid formation. Finally, organotypic slice cultures show that misfolded PrPs mediate inflammation and degeneration of neuronal tissue. Our study establishes a direct link, at the molecular level, between copper exposure and PrP neurotoxicity.