Heat shock proteins and protection of proliferation and translation in mammalian cells.
Heat shock proteins and protection of proliferation and translation in mammalian cells.
复制标题
热休克蛋白和哺乳动物细胞增殖和翻译的保护。
作者：
J. Sciandra;J. Subjeck
本文研究了中国仓鼠卵巢细胞在两种不同的非致死性热休克（41 ℃连续热休克和45 ℃ 5min热休克）后热休克蛋白（HSP）的特性和热耐受诱导。虽然观察到HSP和耐热性的诱导最初同时发展，但观察到HSP诱导不伴随细胞在热应激中存活的能力的任何进一步增加的显著时期。相反，在这些情况下，通过菌落存活率测量的完全耐受状态的实现与HSP诱导的发展停止或开始被抑制的时刻相关。当检测99%致死的45度22分钟热休克时，再次观察到HSP和耐热性同步发展，尽管事实上仅在1%的细胞群体中测量到耐受性。在这种情况下，观察到一种分子量为66，000的新蛋白质，这两种非致死性处理中的任何一种都没有明显诱导。最后，研究了热休克耐热细胞在第二次热攻击（翻译保护）后翻译蛋白质的能力，作为耐热性的替代措施。虽然观察到包括几种正常细胞蛋白的翻译保护，但这种现象与HSP合成的诱导和抑制阶段无关，因此与耐热性无关。
The characteristics of heat shock protein(s) (HSP) and thermotolerance induction were examined in Chinese hamster ovary cells following two diverse nonlethal heat shocks: a continuous 41 degree exposure and a 45 degree, 5-min exposure. While induction of both HSP and thermotolerance were observed to initially develop simultaneously, a significant period was observed during which HSP induction was not accompanied by any further increase in the cells' ability to survive a thermal stress. Conversely, the achievement of the full tolerant state, as measured by colony survival, correlates in these instances with the moment at which development of the induction of HSP either ceased or began to be repressed. When a 99% lethal 45 degree, 22-min heat shock was examined, HSP and a thermal resistance were again observed to develop synchronously, despite the fact that the tolerance was measured in only 1% of the cell population. In this instance, a new protein of molecular weight 66,000 was observed which was not visibly induced by either of the two nonlethal treatments. Finally, the ability of heat-shocked thermotolerant cells to translate proteins following a second heat challenge (protection of translation) was investigated as an alternative measure of thermotolerance. While a protection of translation which encompassed several normal cellular proteins was observed, the phenomenon paralleled the induction and repression phases of HSP synthesis and was therefore not related to thermotolerance.