Proteins containing non-native disulfide bonds generated by oxidative stress can act as signals for the induction of the heat shock response

Autor: Guillermo A. Senisterra, Alice T. McDuffee, Michael L. Freeman, James R. Lepock, Michael J. Borrelli, Steven A. Huntley, Michael J. Meredith, Konjeti R. Sekhar, Jason D. Morrow
Rok vydání: 1997
Předmět:
Zdroj: Journal of Cellular Physiology. 171:143-151
ISSN: 1097-4652
0021-9541
DOI: 10.1002/(sici)1097-4652(199705)171:2<143::aid-jcp4>3.0.co;2-o
Popis: While oxidative stress can induce a heat shock response, the primary signals that initiate activation have not been identified. To identify such signals, HepG2 and V 79 cells were exposed to menadione, a compound that redox-cycles to generate superoxide. The oxidative stress generated by menadione resulted in oxidation of protein thiols in a dose-dependent manner. This was followed by protein destabilization and denaturation, as determined by differential scanning calorimetry of whole cells. To directly evaluate the effect of non-native disulfides on protein conformation, Ca2+-ATPase, isolated from rabbit sarcoplasmic reticulum, was chemically modified to contain non-native intermolecular or glutathione (GHS)-mixed disulfides. Differential scanning calorimetry profiles and 1-anilinonaphthalene-8-sulfonic acid fluorescence indicated that formation of non-native disulfides produced protein destabilization, denaturation, and exposure of hydrophobic domains. Cellular proteins shown to contain oxidized thiols formed detergent-insoluble aggregates. Cells treated with menadione exhibited activation of HSF-1, accumulated Hsp 70 mRNA, and increased synthesis of Hsp 70. This work demonstrates that formation of physiologically relevant, non-native intermolecular and GSH-mixed disulfides causes proteins to destabilize, unfold such that hydrophobic domains are exposed, and initiate a signal for induction of the heat shock response. J. Cell. Physiol. 171:143–151, 1997. © 1997 Wiley-Liss, Inc.
Databáze: OpenAIRE
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