丝裂原活化蛋白激酶信号途径在热休克蛋白90基因表达？…

目的 研究丝裂原活化蛋白激酶－（ＭＡＰＫ）信号传导途径对Ｊｕｒｋａｔ细胞中热休克蛋白９０基因（ｈｓｐ９０）表达的影响。方法 用Ｗｅｓｔｅｒｎ免疫印迹－增强型化学光系统（ＥＣＬ）检测热休克前后Ｊｕｋａｔ细胞外信号调节激酶（ＥＲＫ）、ｐ３８激酶及ｃ－Ｊｕｎ Ｎ－末端蛋白激酶（ＪＮＫ）的底物ｃ－Ｊｕｎ的磷酸化程度;分别用ＪＮＤ１的显性负突变质粒ＤＮ－ＪＮＫ１、ｐ３８ｃＤＮＡ反应表达质粒ａｎｔｉ－ｐ３８及

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.