Abstract
Summary The effect of inhibitors of protein synthesis on RNA synthesis was investigated before and during heat shock. The results indicate that proteins specifically made following heat shock might be required for the resumption, after heat shock, of the synthesis of the RNA normally made at 25°C. It has previously been shown that the heat shock proteins, with the exception of hsp 84, are found in the nucleus bound to chromatin at 37°C, and that they move to the cytoplasm on further incubation of the cells at 25°C (Arrigo et al., 1980). Taken together, these results suggest that some proteins(s) synthesized during heat shock may be involved in the regulation of RNA synthesis. However evidence is presented showing that the newly synthesized proteins at 37° are not involved in repressing the transcription of most of the genes active before the heat shock.