[The role of MAPK pathways in hsp90 genes expression].
OBJECTIVE
To study the effect of mitogen-activated protein kinase (MAPK) pathways on hsp90 genes expression in Jurkat cells.


METHODS
Firstly, the phosphorylation of extracellular signal-regulated protein kinase (ERK), p38 kinase and c-Jun in Jurkat cells were detected by using Western blotting-enhanced chemically lightening (ECL) system. Secondly, Jurkat cells were transfected transiently with c-Jun N-terminal kinase (JNK) dominant negative plasmid, DN-JNK1, p38 cDNA antisense plasmid, anti-p38, respectively or incubated in the present of PD98059, specific inhibitor of ERK kinase. Then the constitutive and heat-induced mRNA levels of hsp90 alpha and hsp90 beta in these cells were determined quantitatively by competitive RT-PCR. The relative mRNA level of hsp90 was compared with those in the cells transfected with mock vector (pCDNA3) or untreated cells respectively.


RESULTS
In the Jurkat cells treated at 45 degrees C for 15 min, the phosphorylation of c-Jun and p38 kinase enhanced obviously, whereas the phosphorylation of ERK increased at certain degree as compared with control. Both constitutive and heat-induced expression of hsp90 genes decreased in the Jurkat cells transfected with DN-JNK1, especially for the heat-induced expression of hsp90 alpha gene which reduced to 68% of that of control. After transfected with anti-p38, the constitutive expression of hsp90 alpha gene and the heat-induced expression of hsp90 beta gene increased by 26% and 22% over the control. The constitutive expression of hsp90 alpha and hsp90 beta genes in the Jurkat cells treated with PD98059, increased to 46% and 16% of the control respectively, whereas the heat-induced expression of hsp90 genes did not change.


CONCLUSIONS
Evidences showed that ERK signal pathway inhibited the constitutive expression of hsp90 genes in Jurkat cell. JNK pathway promoted both constitutive and heat-induced expression of hsp90 genes, whereas p38 pathway may not play an important role in the hsp90 genes expression.
Li
J
J
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, CAMS, PUMC, Beijing 100005, China.
Wu
N
N
Shen
Y
Y
D015870:Gene Expression; D005786:Gene Expression Regulation; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D019169:Jurkat Cells; D020935:MAP Kinase Signaling System / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases
D018841:HSP90 Heat-Shock Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases