Heat shock and oxidative stress-induced exposure of hydrophobic protein domains as common signal in the induction of hsp68.
J Biol Chem
; 276(3): 1814-21, 2001 Jan 19.
Article
en En
| MEDLINE
| ID: mdl-11042186
The hypothesis of a common signal for heat shock (HS) and oxidative stress (OS) was analyzed in C6 cells with regard to the induction of heat shock proteins (Hsps). The synthesis rate and level of the strictly inducible Hsp68 was significantly higher after HS (44 degrees C) compared with OS (2 mm H2O2). This difference corresponded to higher and lower activation of the heat shock factor (HSF) by HS and OS, respectively. OS, on the other hand, showed stronger cytotoxicity compared with HS as indicated by drastic lipid peroxidation and inhibition of protein synthesis as well as of mitochondrial and endocytotic activity. Lactic dehydrogenase also revealed stronger inhibition of enzyme activity by OS than by HS as shown in cells and in vitro experiments. Conformational analysis of lactic dehydrogenase by the fluorophore 1-anilinonaphtalene-8-sulfonic acid, however, showed stronger exposure of hydrophobic domains after HS than after OS which correlates positively with the Hsp68 response. Treatment of cells with deoxyspergualin, which exhibits high affinity to Hsps, the putative inhibitors of HSF, strongly increased only OS-induced hsp68 expression. In conclusion, the results suggest that exposure of hydrophobic domains of cytosolic proteins represents the common first signal in the multistep activation pathway of HSF.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Estrés Oxidativo
/
Proteínas HSP70 de Choque Térmico
/
Respuesta al Choque Térmico
Límite:
Animals
Idioma:
En
Revista:
J Biol Chem
Año:
2001
Tipo del documento:
Article
País de afiliación:
Noruega
Pais de publicación:
Estados Unidos