Ballinger D G, Pardue M L
Cell. 1983 May;33(1):103-13. doi: 10.1016/0092-8674(83)90339-2.
When Drosophila tissue culture cells are shifted from 25 to 36 degrees C (heat shocked) the pre-existing mRNAs (25 degrees C mRNAs) remain in the cytoplasm but their translation products are underrepresented relative to the induced heat shock proteins. Many of these undertranslated 25 degrees C mRNAs are found in association with polysomes of similar size in heat-shocked and control cells. Furthermore, the messages encoding alpha-tubulin, beta-tubulin, and actin are found associated with one-third to one-half as many total ribosomes in heat-shocked cells as in cells incubated at 25 degrees C. Increased temperature should lead to increased output of protein per ribosome. However, the 25 degrees C proteins are actually synthesized at less than 10% of 25 degrees C levels in heat-shocked cells. Thus, the rates of both elongation and initiation of translation are significantly (15- to 30-fold) slower on 25 degrees C mRNAs than they are on heat shock mRNAs in heat-shocked cells.
当果蝇组织培养细胞从25摄氏度转移至36摄氏度（热休克）时，先前存在的mRNA（25摄氏度mRNA）会保留在细胞质中，但相对于诱导产生的热休克蛋白，它们的翻译产物所占比例较低。在热休克细胞和对照细胞中，许多这些翻译不足的25摄氏度mRNA与大小相似的多核糖体相关联。此外，编码α-微管蛋白、β-微管蛋白和肌动蛋白的信使RNA在热休克细胞中与核糖体总数的关联程度仅为在25摄氏度孵育细胞中的三分之一至二分之一。温度升高应会导致每个核糖体的蛋白质产量增加。然而，在热休克细胞中，25摄氏度蛋白质的实际合成量不到25摄氏度水平的10%。因此，在热休克细胞中，25摄氏度mRNA的翻译延伸和起始速率均显著慢于热休克mRNA（慢15至30倍）。
