Alpha-synuclein delays endoplasmic reticulum (ER)-to-Golgi transport in mammalian cells by antagonizing ER/Golgi SNAREs.
Alpha-synuclein delays endoplasmic reticulum (ER)-to-Golgi transport in mammalian cells by antagonizing ER/Golgi SNAREs.
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DOI：
10.1091/mbc.e09-09-0801
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发表时间：
2010-06-01
影响因子：
3.3
通讯作者：
Hay JC
中科院分区：
文献类型：
--
作者：
Thayanidhi N;Helm JR;Nycz DC;Bentley M;Liang Y;Hay JC
这项工作表明，α-突触核蛋白抑制哺乳动物细胞的生物合成分泌途径，有效和直接在无毒条件下，在不溶性α-突触核蛋白聚集体的情况下。阐明了α-突触核蛋白与ER/Golgi SNARE结合并抑制融合SNARE复合物组装的潜在机制。当在简单生物体中表达时，人α-突触核蛋白的毒性可以通过内质网（ER）-高尔基体转运机制的过表达来抑制，这表明组成性分泌的抑制是毒性的根本原因。哺乳动物中类似的抑制是否代表家族性帕金森病的原因尚未确定。我们通过在哺乳动物肾脏和神经内分泌细胞中表达人α-突触核蛋白并评估ER到高尔基体的转运来测试这一假设的要素。野生型或家族性疾病相关的A53 T突变体α-突触核蛋白的过表达使转运延迟高达50%;然而，A53 T的抑制作用更强。分泌延迟发生在低表达水平，并且不伴有不溶性α-突触核蛋白聚集体或转运机制的错误启动，表明可溶性α-突触核蛋白对运输蛋白的直接作用。ER/高尔基体精氨酸可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（R-SNARE）的共过表达特异性地拯救了转运，表明α-突触核蛋白拮抗SNARE功能。ykt 6比sec 22 b更有效地逆转α-突触核蛋白抑制，这表明ykt 6在神经元中神秘的高表达可能具有神经保护作用。在体外重组中，纯化的α-突触核蛋白A53 T蛋白特异性地抑制COPII囊泡在前高尔基体步骤的对接和融合。最后，可溶性α-突触核蛋白A53 T直接结合ER/Golgi SNARE并抑制SNARE复合物组装，为早期分泌途径中的毒性作用提供了潜在机制。
This work demonstrates that α-synuclein inhibits the biosynthetic secretory pathway of mammalian cells potently and directly under nontoxic conditions and in the absence of insoluble α-synuclein aggregates. A potential mechanism involving α-synuclein binding to ER/Golgi SNAREs and inhibiting fusogenic SNARE complex assembly is elucidated. Toxicity of human α-synuclein when expressed in simple organisms can be suppressed by overexpression of endoplasmic reticulum (ER)-to-Golgi transport machinery, suggesting that inhibition of constitutive secretion represents a fundamental cause of the toxicity. Whether similar inhibition in mammals represents a cause of familial Parkinson's disease has not been established. We tested elements of this hypothesis by expressing human α-synuclein in mammalian kidney and neuroendocrine cells and assessing ER-to-Golgi transport. Overexpression of wild type or the familial disease-associated A53T mutant α-synuclein delayed transport by up to 50%; however, A53T inhibited more potently. The secretory delay occurred at low expression levels and was not accompanied by insoluble α-synuclein aggregates or mistargeting of transport machinery, suggesting a direct action of soluble α-synuclein on trafficking proteins. Co-overexpression of ER/Golgi arginine soluble N-ethylmaleimide-sensitive factor attachment protein receptors (R-SNAREs) specifically rescued transport, indicating that α-synuclein antagonizes SNARE function. Ykt6 reversed α-synuclein inhibition much more effectively than sec22b, suggesting a possible neuroprotective role for the enigmatic high expression of ykt6 in neurons. In in vitro reconstitutions, purified α-synuclein A53T protein specifically inhibited COPII vesicle docking and fusion at a pre-Golgi step. Finally, soluble α-synuclein A53T directly bound ER/Golgi SNAREs and inhibited SNARE complex assembly, providing a potential mechanism for toxic effects in the early secretory pathway.
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影响因子：
4
作者：
Townley, Anna K.;Feng, Yi;Stephens, David J.
通讯作者：
Stephens, David J.
DOI：
10.1016/j.biocel.2004.05.009
发表时间：
2004-12
期刊：
The international journal of biochemistry & cell biology
影响因子：
--
作者：
Tanida I;Ueno T;Kominami E
通讯作者：
Kominami E
复菌囊泡融合的重建以产生高尔基前中间室。
影响因子：
7.8
作者：
Xu, DL;Hay, JC
通讯作者：
Hay, JC
影响因子：
4.8
作者：
Bentley, Marvin;Liang, Yingjian;Hay, Jesse C.
通讯作者：
Hay, Jesse C.
影响因子：
64.8
作者：
McNew, JA;Parlati, F;Rothman, JE
通讯作者：
Rothman, JE