Hatayama T, Kano E, Taniguchi Y, Nitta K, Wakatsuki T, Kitamura T, Imahara H
Department of Biochemistry, Kyoto Pharmaceutical University, Japan.
Int J Hyperthermia. 1991 Jan-Feb;7(1):61-74. doi: 10.3109/02656739109004977.
To examine the involvement of heat shock proteins in the induction of thermotolerance in Chinese hamster V79 cells, thermotolerance was induced by heating of the cells at 42 degrees C for 4 h or at 44 degrees C for 20 min, or by treatment of the cells with 50 microM sodium arsenite for 3 h or 20 micrograms/ml puromycin for 4 h. Under unstressed conditions V79 cells synthesized constitutively three major heat-shock proteins, hsp70, hsp85 and hsp105. On exposure to conditions under which thermotolerance was induced, the synthesis of constitutive hsp70, hsp85 and hsp105 increased, but the inducible form of hsp70 was not synthesized, indicating that this inducible form was not necessary for the induction of thermotolerance. Although the amounts of heat-shock proteins synthesized in the cells that acquired thermotolerance were not always more than those synthesized constitutively in unstressed cells, the stressed cells synthesized heat-shock proteins (especially hsp70) preferentially over other proteins. As the level of hsp70 in the thermotolerant cells was almost the same as that in unstressed cells, the specific accumulation of hsp70 seemed not to be required for the acquisition of thermotolerance. From these findings it seemed likely that, for the induction of thermotolerance in V79 cells, hsp70 preferentially synthesized during or after the stress has an important function. Or the synthesis of heat shock proteins may not be important, and constitutively synthesized heat-shock proteins acquire a specific function during or after the stress.
为了研究热休克蛋白在中国仓鼠V79细胞耐热性诱导过程中的作用，通过以下方式诱导耐热性：将细胞在42℃加热4小时或在44℃加热20分钟，或者用50微摩尔/升的亚砷酸钠处理细胞3小时或用20微克/毫升的嘌呤霉素处理细胞4小时。在非应激条件下，V79细胞组成性地合成三种主要的热休克蛋白，即hsp70、hsp85和hsp105。在暴露于诱导耐热性的条件下，组成性的hsp70、hsp85和hsp105的合成增加，但诱导型hsp70未被合成，这表明这种诱导型对于耐热性的诱导并非必需。尽管获得耐热性的细胞中合成的热休克蛋白的量并不总是超过非应激细胞中组成性合成的量，但应激细胞优先于其他蛋白质合成热休克蛋白（尤其是hsp70）。由于耐热细胞中hsp70的水平与非应激细胞中的几乎相同，hsp70的特异性积累似乎对于获得耐热性并非必需。从这些发现来看，对于V79细胞耐热性的诱导，应激期间或之后优先合成的hsp70可能具有重要作用。或者热休克蛋白的合成可能并不重要，组成性合成的热休克蛋白在应激期间或之后获得了特定功能。
