Live-cell imaging reveals divergent intracellular dynamics of polyglutamine disease proteins and supports a sequestration model of pathogenesis
Live-cell imaging reveals divergent intracellular dynamics of polyglutamine disease proteins and supports a sequestration model of pathogenesis
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DOI：
10.1073/pnas.152101299
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发表时间：
2002-07-09
影响因子：
11.1
通讯作者：
Paulson, HL
中科院分区：
文献类型：
--
作者：
Chai, YH;Shao, JQ;Paulson, HL
蛋白质错误折叠和聚集是聚谷氨酰胺神经退行性疾病的核心特征，但扩展的聚谷氨酰胺蛋白质的动态特性却知之甚少。在这里，我们利用光漂白后的荧光恢复（FRAP）和光漂白中的荧光损失（FLIP）与绿色荧光蛋白融合蛋白来研究活细胞中的聚谷氨酰胺蛋白动力学。我们的结果揭示了扩展的聚谷氨酰胺蛋白 ataxin-3 的显着不同的迁移状态，并确定由该蛋白形成的核内含物是聚集体。对绿色荧光蛋白标记的 cAMP 反应元件结合蛋白与两种突变型聚谷氨酰胺蛋白（ataxin-3 和亨廷顿蛋白）共表达的其他研究支持了一种疾病模型，其中转录成分的共聚集有助于发病机制。最后，对第三种多聚谷氨酰胺疾病蛋白 ataxin-1 的研究揭示了不同疾病蛋白形成的内含物动力学中意想不到的异质性，这一发现可能有助于解释这些神经退行性疾病发病机制的疾病特异性要素。
Protein misfolding and aggregation are central features of the polyglutamine neurodegenerative disorders, but the dynamic properties of expanded polyglutamine proteins are poorly understood. Here, we use fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP) with green fluorescent protein fusion proteins to study polyglutamine protein kinetics in living cells. Our results reveal markedly divergent mobility states for an expanded polyglutamine protein, ataxin-3, and establish that nuclear inclusions formed by this protein are aggregates. Additional studies of green fluorescent protein tagged cAMP response element binding protein coexpressed with either of two mutant polyglutamine proteins, ataxin-3 and huntingtin, support a model of disease in which coaggregation of transcriptional components contributes to pathogenesis. Finally, studies of a third polyglutamine disease protein, ataxin-1, reveal unexpected heterogeneity in the dynamics of inclusions formed by different disease proteins, a finding which may help explain disease-specific elements of pathogenesis in these neurodegenerative disorders.