Induction of heat-shock proteins by glutamine. The 'feeding effect'.
Subconfluent, log-phase Chinese hamster ovary cells induced the major heat-shock proteins (hsp) when cells were refed, 40 hours after seeding. This method of inducing heat-shock proteins was also obtained by refeeding with fresh serum-free media, but not with media with a long shelf life or with media prepared without glutamine. It was observed that addition of glutamine alone to cultures at 40 hours post-seeding induced heat-shock proteins. Addition of ammonium chloride, however, had no discernible effect on heat-shock protein synthesis. Northern blot analysis indicated that this phenomenon reflected an increase in the levels of message for the constitutive/inducible member of the hsp 70 family, but not the non-constitutive member. To determine the effect of this induction on heat sensitivity, unfed and 'heat-shock-induced' refed cultures were heated at 45 degrees C. No significant difference in cell survival was observed. Therefore glutamine is the necessary ingredient required for the induction of heat-shock proteins and this method of inducing heat-shock proteins does not alter heat sensitivity.
Cai
J W
JW
Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York 14263.
Hughes
C S
CS
Shen
J W
JW
Subjeck
J R
JR
D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000187:drug effects*; D005973:Glutamine / Q000494:pharmacology*; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D007700:Kinetics; D013696:Temperature
D006360:Heat-Shock Proteins; D000643:Ammonium Chloride; D005973:Glutamine