The pattern of protein synthesis induced by heat shock of HeLa cells

While incubation of HeLa cells for 5--10 min at 45 degrees C does not affect subsequent cellular growth and DNA synthesis at 37 degrees C, there is an increased synthesis of specific proteins in the molecular weight region of 100 000, 72 000--74 000 and 37 000. The synthesis of these proteins reaches a maximum 2 h after the heat shock and while the protein themselves are stable, their synthesis declines to normal levels 4 h afterwards. The increased synthesis is blocked by actinomycin D but the addition of cycloheximide or NaF during the "induction' period is without effect.