Heat(40 degrees C)-induced polypeptides in human embryonic fibroblasts.

The synthesis of 3 polypeptides with molecular weights of 103-, 80- and 78-kdalton (K) was dramatically accelerated when the cultures of human embryonic fibroblasts were transferred from 37 to 40 degrees C. The induction of these polypeptides was not observed if actinomycin D was added to the cultures at the beginning of the rising of the temperature, indicating that this response may be mediated by increased transcription of their messenger RNA.