Effect of amino acid analogs on the development of thermotolerance and on thermotolerant cells.
Exposure of HA-1 Chinese hamster fibroblasts to amino acid analogs has been shown to have a heat-sensitizing effect as well as inducing the heat shock response (Li and Laszlo, 1985a). In this study, we have examined the effect of amino acid analogs on the development of thermotolerance after a brief heat shock or exposure to sodium arsenite and the effect of amino acid analogs on cells that are already thermotolerant. Exposure of HA-1 cells to amino acid analogs inhibited the development of thermotolerance following a mild heat shock or treatment with sodium arsenite. However, cells that were already thermotolerant were resistant to the sensitizing action of amino acid analogs. The refractoriness of thermotolerant cells to amino acid analog treatment developed in parallel with thermotolerance. The uptake of the arginine analog, canavanine, and its incorporation into proteins was not altered in the thermotolerant cells. Furthermore, another biological consequence of exposure to amino acid analogs, sensitization to ionizing radiation, also was not altered in the thermotolerant cells. The inhibition of the development of thermotolerance by amino acid analogs and the refractoriness of thermotolerant cells to the heat-sensitizing action of amino acid analogs lend further support the role of heat-shock proteins in the phenomenon of thermotolerance.
Laszlo
A
A
Section of Cancer Biology, Mallinckrodt Institute of Radiology, Washington University Medical Center, St. Louis, Missouri 63108.
Li
G C
GC
D000596:Amino Acids / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001151:Arsenic / Q000494:pharmacology; D018053:Arsenites; D001384:Azetidines / Q000494:pharmacology; D002172:Canavanine / Q000494:pharmacology; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D006358:Hot Temperature; D017670:Sodium Compounds
D000596:Amino Acids; D018053:Arsenites; D001384:Azetidines; D006360:Heat-Shock Proteins; D017670:Sodium Compounds; D002172:Canavanine; C017947:sodium arsenite; D001151:Arsenic