Bag J
Eur J Biochem. 1983 Oct 3;135(3):373-8. doi: 10.1111/j.1432-1033.1983.tb07664.x.
Exposure of chick myotube cultures to a temperature (45 degrees C) higher than their normal growing temperature (37 degrees C) caused extensive synthesis of three major polypeptides of Mr = 25 000, 65 000 and 81 000 referred to as 'heat-shock polypeptides' (hsps). When these cells were allowed to recover from heat-shock treatment at 37 degrees C for 6-8 h, the rate of accumulation of isotope into the 65 000-Mr and 81 000-Mr hsps declined to levels comparable to those in control cultures maintained at 37 degrees C. However, incorporation of isotope in the 25 000-Mr hsp continued at an elevated rate for a longer period than the 65 000-Mr and 81 000-Mr hsps. When heat-shocked cells were allowed to recover at 37 degrees C in the presence of actinomycin D to block new mRNA synthesis, the hsp synthesis as measured by the incorporation of radioactive isotope in these polypeptides continued at levels comparable to those in heat-shocked cells prior to recovery. The block of recovery by actinomycin D was due to the presence of a greater amount of functional hsp mRNAs in the polysomes as compared to untreated controls. The role of competition between the mRNAs for hsps and normal cellular proteins for the translation machinery in regulating protein synthesis during the recovery from heat shock has been discussed.
将鸡肌管培养物暴露于高于其正常生长温度（37℃）的温度（45℃）下，会导致大量合成三种主要的多肽，其分子量分别为25000、65000和81000，被称为“热休克多肽”（hsps）。当这些细胞在37℃下从热休克处理中恢复6 - 8小时后，同位素在分子量为65000和81000的热休克多肽中的积累速率下降到与在37℃下维持的对照培养物相当的水平。然而，同位素在分子量为25000的热休克多肽中的掺入以高于65000和81000分子量热休克多肽的速率持续更长时间。当热休克细胞在放线菌素D存在下于37℃恢复以阻断新的mRNA合成时，通过这些多肽中放射性同位素掺入所测量的热休克多肽合成继续维持在与恢复前热休克细胞相当的水平。放线菌素D对恢复的阻断是由于与未处理的对照相比，多核糖体中存在更多功能性的热休克多肽mRNA。文中讨论了热休克多肽mRNA与正常细胞蛋白质的mRNA在恢复热休克过程中竞争翻译机制对调节蛋白质合成的作用。
