Heat shock protein 27 stimulates recovery of RNA and protein synthesis following a heat shock.
Constitutive expression of human hsp27 resulted in a 100-fold increase in survival to a single lethal heat shock in CHO cells without effecting the development of thermotolerance. A possible mechanism for the thermoprotective function of hsp27 may be increased recovery of protein synthesis and RNA synthesis following a heat shock. A lethal heat shock (44 degrees C, 30 min) results in a 90% reduction in the rate of protein synthesis in non-tolerant cells. Control transfected cells recovered protein synthesis to a pre-heat shock rate 10 h after the heat shock; while cell lines that constitutively express human hsp27 recovered 6 h after the heat shock. Thermotolerant cells had a 50% reduction in protein synthesis, which recovered within 7 h following the heat shock. The same lethal heat shock (44 degrees C, 30 min) reduced RNA synthesis by 60% in the transfected cell lines, with the controls recovering in 7 h; while the hsp27 expressing cell lines recovered within 5 h. Thermotolerant cells had a 40% reduction in RNA synthesis and were able to recover within 4 h. The enhanced ability of hsp27 to facilitate recovery of protein synthesis and RNA synthesis following a heat shock may provide the cell with a survival advantage.
Carper
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SW
Department of Chemistry, University of Nevada, Las Vegas 89154, USA. carpers@nevada.edu
Rocheleau
T A
TA
Cimino
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D
Storm
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FK
D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects; D002999:Clone Cells; D006224:Cricetinae; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000502:physiology*; D006358:Hot Temperature; D047908:Intracellular Signaling Peptides and Proteins; D014176:Protein Biosynthesis; D011489:Protein Denaturation; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011506:Proteins / Q000187:drug effects; D012313:RNA / Q000096:biosynthesis* / Q000187:drug effects; D000520:alpha-Glucosidases / Q000378:metabolism; D000099190:MAP-Kinase-Activated Kinase 2
D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D012313:RNA; D000520:alpha-Glucosidases; D000099190:MAP-Kinase-Activated Kinase 2