Synphilin-1 enhances α-synuclein aggregation in yeast and contributes to cellular stress and cell death in a Sir2-dependent manner.
Synphilin-1 enhances α-synuclein aggregation in yeast and contributes to cellular stress and cell death in a Sir2-dependent manner.
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DOI：
10.1371/journal.pone.0013700
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发表时间：
2010-10-27
期刊：
影响因子：
3.7
通讯作者：
Winderickx J
中科院分区：
文献类型：
--
作者：
Büttner S;Delay C;Franssens V;Bammens T;Ruli D;Zaunschirm S;de Oliveira RM;Outeiro TF;Madeo F;Buée L;Galas MC;Winderickx J
帕金森氏病的特征是存在被称为路易体的细胞质内含物，内含聚集的α-突触核蛋白及其相互作用伙伴突触蛋白-1。虽然已知synphilin-1可以加速哺乳动物细胞中α-突触核蛋白的包涵体形成，但其对细胞毒性的影响尚不清楚。我们在酿酒酵母中单独或与α-突触核蛋白联合表达野生型synphilin-1或其R621C突变体，并监测这些蛋白在细胞内的定位和包涵形成以及对生长、氧化应激和细胞死亡的影响。我们发现野生型和突变型synphilin-1在酵母细胞中形成包涵体，并通过α-synuclein加速包涵体的形成，后者与丝氨酸-129磷酸化增强有关。Synphilin-1包涵体与脂滴和内膜共定位。一致地，我们发现野生型和突变型synphilin-1与抗洗涤剂膜结构域（称为脂筏）相互作用。在指数培养中，synphilin-1的表达并没有引起明显的生长缺陷，这可能是由于聚合体的形成和包涵体从子细胞逆行运输回母细胞。然而，当培养物接近固定阶段和随后的酵母细胞老化过程中，野生型和突变型synphilin-1都降低了存活，并引发了细胞凋亡和坏死死亡，尽管程度不同。最有趣的是，在缺乏sirtuin Sir2的衰老细胞中，synphilin-1不会引发细胞毒性。这表明野生型细胞中synphilin-1的表达会导致sir2依赖性过程的失调，例如在营养匮乏的情况下维持自噬通量。我们的研究结果表明，野生型和突变型synphilin-1是脂筏相互作用蛋白，在酵母中表达时形成内含物并加速α-synuclein的内含物形成。Synphilin-1因此诱导细胞毒性，这种作用在野生型蛋白中最为明显，并通过sir2依赖性过程介导。
Parkinson's disease is characterized by the presence of cytoplasmic inclusions, known as Lewy bodies, containing both aggregated α-synuclein and its interaction partner, synphilin-1. While synphilin-1 is known to accelerate inclusion formation by α-synuclein in mammalian cells, its effect on cytotoxicity remains elusive. We expressed wild-type synphilin-1 or its R621C mutant either alone or in combination with α-synuclein in the yeast Saccharomyces cerevisiae and monitored the intracellular localization and inclusion formation of the proteins as well as the repercussions on growth, oxidative stress and cell death. We found that wild-type and mutant synphilin-1 formed inclusions and accelerated inclusion formation by α-synuclein in yeast cells, the latter being correlated to enhanced phosphorylation of serine-129. Synphilin-1 inclusions co-localized with lipid droplets and endomembranes. Consistently, we found that wild-type and mutant synphilin-1 interacts with detergent-resistant membrane domains, known as lipid rafts. The expression of synphilin-1 did not incite a marked growth defect in exponential cultures, which is likely due to the formation of aggresomes and the retrograde transport of inclusions from the daughter cells back to the mother cells. However, when the cultures approached stationary phase and during subsequent ageing of the yeast cells, both wild-type and mutant synphilin-1 reduced survival and triggered apoptotic and necrotic cell death, albeit to a different extent. Most interestingly, synphilin-1 did not trigger cytotoxicity in ageing cells lacking the sirtuin Sir2. This indicates that the expression of synphilin-1 in wild-type cells causes the deregulation of Sir2-dependent processes, such as the maintenance of the autophagic flux in response to nutrient starvation. Our findings demonstrate that wild-type and mutant synphilin-1 are lipid raft interacting proteins that form inclusions and accelerate inclusion formation of α-synuclein when expressed in yeast. Synphilin-1 thereby induces cytotoxicity, an effect most pronounced for the wild-type protein and mediated via Sir2-dependent processes.
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影响因子：
4.3
作者：
Eyal, Allon;Engelender, Simone
通讯作者：
Engelender, Simone
影响因子：
2.5
作者：
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