Cycles of protein condensation and discharge in nuclear organelles studied by fluorescence lifetime imaging
Cycles of protein condensation and discharge in nuclear organelles studied by fluorescence lifetime imaging
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通过荧光寿命成像研究核细胞器中蛋白质凝结和放电的循环
DOI：
10.1038/s41467-019-08354-3
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发表时间：
2019-01-28
影响因子：
16.6
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
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作者：
Pliss, Artem;Levchenko, Svitlana M.;Prasad, Paras N.
核细胞器是粘性液滴，由可溶性蛋白质的浓度依赖性冷凝和液-液相分离产生。人们正在积极研究核细胞器在细胞调节和疾病中的作用。然而，这些研究在活细胞中进行非常具有挑战性，因此，它们的物理化学特性仍然知之甚少。在这项研究中，我们描述了一种荧光寿命成像方法，用于实时监测活培养细胞核细胞器中的蛋白质凝结。这种方法揭示了主要核细胞器（包括核仁、核斑点、卡哈尔小体以及异染色质簇）中蛋白质浓度的惊人大的周期性变化。值得注意的是，同一细胞的不同细胞器的蛋白质浓度变化是同步的。我们提出了一种负责核细胞器中蛋白质同步积累的分子机制。这种机制可以用于细胞代谢的一般调节，并有助于基因表达的协调。
Nuclear organelles are viscous droplets, created by concentration-dependent condensation and liquid-liquid phase separation of soluble proteins. Nuclear organelles have been actively investigated for their role in cellular regulation and disease. However, these studies are highly challenging to perform in live cells, and therefore, their physico-chemical properties are still poorly understood. In this study, we describe a fluorescence lifetime imaging approach for real-time monitoring of protein condensation in nuclear organelles of live cultured cells. This approach unravels surprisingly large cyclic changes in concentration of proteins in major nuclear organelles including nucleoli, nuclear speckles, Cajal bodies, as well as in the clusters of heterochromatin. Remarkably, protein concentration changes are synchronous for different organelles of the same cells. We propose a molecular mechanism responsible for synchronous accumulations of proteins in the nuclear organelles. This mechanism can serve for general regulation of cellular metabolism and contribute to coordination of gene expression.