Heat shock activated Rac-MEKK-JNK pathway and hsp90 beta gene expression.
- Author:
Xiao-yan LI
1
;
Cheng LU
;
Ning-hua WU
;
Yu-fei SHEN
Author Information
- Publication Type:Journal Article
- MeSH: Benzoquinones; Cell Line, Tumor; Genes, Reporter; HSP90 Heat-Shock Proteins; biosynthesis; genetics; Hot Temperature; Humans; JNK Mitogen-Activated Protein Kinases; Lactams, Macrocyclic; Leukemia, T-Cell; pathology; Mitogen-Activated Protein Kinase Kinases; physiology; Mitogen-Activated Protein Kinases; physiology; Protein Kinase C; physiology; Quinones; pharmacology; Signal Transduction; Transfection
- From: Acta Academiae Medicinae Sinicae 2002;24(3):264-268
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo study the effect of Rac-MEKK-JNK (Rac-mitogen activated protein kinase kinase kinase-C-jun N-terminal protein kinase) signal pathway on heat shock-induced hsp90 beta gene expression and the impact of Hsp90 on the regulation of the pathway.
METHODSDN-Rac, DN-MEKK or DN-JNK were cotransfected with hsp90 beta CAT reporter plasmid beta 3.1 into Jurkat or LETPa-2 cells individually, the CAT mRNA expression was then determined quantitatively by competitive RT-PCR based system. Western blot was carried out to detect the expression level and phosphorylation of c-Jun in Jurkat and LETPa-2 cells that were transfected with DN-Rac, DN-MEKK or DN-JNK. By in vitro kinase activity assay and Western blot, the effect of geldnamycin (GA) on heat induced JNK activity were evaluated.
RESULTSIn Jurkat cell transfected with DN-Rac, DN-MEKK or DN-JNK, heat shock induced relative CAT mRNA expression level was decreased to (72.8 +/- 5)%, (60 +/- 13.2)% and (47.7 +/- 12.1)% of the control respectively; while in LETPa-2 cell hsp90 beta 3.1 reporter gene expression was accordingly suppressed to (16.17 +/- 5.1)%, (50.2 +/- 8.7)% and (47.5 +/- 10)% of control. C-Jun expression and phosphorylation were inhibited by the transfection of either one of DN-Rac, DN-MEKK or DN-JNK. With GA treatment, heat shock induced JNK activity was repressed, while the expression level of JNK or c-Jun was not obviously changed.
CONCLUSIONSRac-MEKK-JNK pathway promotes heat shock induced hsp90 beta gene expression and hsp90 may participate in the regulation of heat shock activated Rac-MEKK-JNK signal pathway in both Jurkat and LETPa-2 cells.