Hypertonic stress induces rapid and widespread protein damage in C. elegans
Hypertonic stress induces rapid and widespread protein damage in C. elegans
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DOI：
10.1152/ajpcell.00030.2011
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发表时间：
2011-09-01
影响因子：
5.5
通讯作者：
Strange, Kevin
中科院分区：
文献类型：
--
作者：
Burkewitz, Kris;Choe, Keith;Strange, Kevin
Burkewitz K，Choe K，Strange K.高渗应激诱导C.优雅的。美国生理学杂志细胞生理学301：C566-C576，2011年。首次发表于2011年5月25日; doi：10.1152/ajpcell.00030.2011。蛋白质稳态被定义为维持所有细胞质蛋白质功能的稳态机制。我们最近证明，蛋白质稳态网络的能力是一个关键因素，它定义了高渗环境中细胞和生物体生存的极限。目前的研究是为了确定细胞失水引起的蛋白质损伤的程度。使用蠕虫菌株表达荧光标记的外源和内源性蛋白质和蛋白质与温度敏感的点突变，我们证明，高渗应力导致聚集和错误折叠的不同蛋白质在多种细胞类型。蛋白质损伤迅速。多聚谷氨酰胺黄色荧光蛋白报告分子的聚集在< 1小时的高渗应激下可观察到，聚集体体积大约每10分钟翻一番。聚集体形成是不可逆的，在暴露于高渗条件下10分钟后就发生了。为了确定内源性蛋白质是否被高渗应激聚集，我们定量了洗涤剂不溶性提取物中存在的总细胞蛋白质的相对量。暴露于400 mM或500 mM NaCl 4 h诱导内源性蛋白质聚集增加55-120%。抑制胰岛素信号传导或适应轻度高渗应激增加了极端高渗条件下的存活率，并防止了内源性蛋白质的聚集。我们的结果表明，高渗应激会导致广泛而严重的蛋白质损伤，并且细胞具有重塑蛋白质网络的显着能力，这些蛋白质网络的功能是维持蛋白质稳态。这些发现对于理解细胞如何科普高渗应激和其他蛋白质损伤应激源具有重要意义。
Burkewitz K, Choe K, Strange K. Hypertonic stress induces rapid and widespread protein damage in C. elegans. Am J Physiol Cell Physiol 301: C566-C576, 2011. First published May 25, 2011; doi: 10.1152/ajpcell.00030.2011.-Proteostasis is defined as the homeostatic mechanisms that maintain the function of all cytoplasmic proteins. We recently demonstrated that the capacity of the proteostasis network is a critical factor that defines the limits of cellular and organismal survival in hypertonic environments. The current studies were performed to determine the extent of protein damage induced by cellular water loss. Using worm strains expressing fluorescently tagged foreign and endogenous proteins and proteins with temperature-sensitive point mutations, we demonstrate that hypertonic stress causes aggregation and misfolding of diverse proteins in multiple cell types. Protein damage is rapid. Aggregation of a polyglutamine yellow fluorescent protein reporter is observable with < 1 h of hypertonic stress, and aggregate volume doubles approximately every 10 min. Aggregate formation is irreversible and occurs after as little as 10 min of exposure to hypertonic conditions. To determine whether endogenous proteins are aggregated by hypertonic stress, we quantified the relative amount of total cellular protein present in detergent-insoluble extracts. Exposure for 4 h to 400 mM or 500 mM NaCl induced a 55-120% increase in endogenous protein aggregation. Inhibition of insulin signaling or acclimation to mild hypertonic stress increased survival under extreme hypertonic conditions and prevented aggregation of endogenous proteins. Our results demonstrate that hypertonic stress causes widespread and dramatic protein damage and that cells have a significant capacity to remodel the network of proteins that function to maintain proteostasis. These findings have important implications for understanding how cells cope with hypertonic stress and other protein-damaging stressors.