Lee Y J, Borrelli M J, Corry P M
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073.
Biochem Biophys Res Commun. 1991 May 15;176(3):1525-31. doi: 10.1016/0006-291x(91)90460-o.
To investigate the possibility that nascent polypeptides released from polysomes by heat shock accumulate in the nucleus, cells were pulse labeled with [35S]methionine for two minutes and heated immediately thereafter at 45.5 degrees C for 10 minutes. When isolated nuclei were subjected to gel electrophoresis and subsequently autoradiographed, heated nuclei exhibited an approximately 10-fold increase in radioactive polypeptides in comparison to nonheated controls. These nascent polypeptides were nonspecific molecules covering a wide range of molecular weights. It is plausible that the accumulation of polypeptides in the nucleus results in hyperthermic cytotoxicity. Therefore, we propose that a potential target for heat killing is within the nucleus, at sites where nascent polypeptides accumulate after heat shock.
