Okadaic acid markedly potentiates the heat-induced hsp 70 promoter activity.
Okadaic acid markedly potentiates the heat-induced hsp 70 promoter activity.
复制标题
冈田酸显着增强热诱导的 hsp 70 启动子活性。
DOI：
10.1016/s0021-9258(18)54094-1
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
A. Y. Liu
中科院分区：
文献类型：
--
作者：
N. Chang;L. Huang;A. Y. Liu
研究了丝氨酸/苏氨酸磷酸酶2A和1的强效特异性抑制剂冈田酸（OA）转染N-18小鼠神经母细胞瘤细胞后，对人hsp 70启动子连锁氯霉素乙酰转移酶基因瞬时表达的影响。报告基因活性分析显示，纳米浓度的OA显著增强了热诱导的pHBCAT（一种全长hsp70启动子驱动的氯霉素乙酰转移酶基因构建体）的表达（但不是基础）。OA的这种作用是剂量依赖性和启动子特异性的，似乎是由于抑制蛋白磷酸酶2A而不是蛋白磷酸酶1。OA增强热诱导pHBCAT表达的能力似乎是几种不同细胞类型所共有的特征。我们提出热诱导的热休克基因的转录激活与转录复合体组分的磷酸化有关，而OA增强了这种磷酸化，从而增强了热诱导的hsp 70启动子的活性。
The effects of okadaic acid (OA), a potent and specific inhibitor of serine/threonine phosphatases 2A and 1, on the transient expression of a human hsp 70 promoter-linked chloramphenicol acetyltransferase gene transfected into N-18 mouse neuroblastoma cells were determined. Assays of reporter gene activity showed that nanomolar concentrations of OA markedly potentiated the heat-induced (but not the basal) expression of pHBCAT, a full-length hsp 70 promoter-driven chloramphenicol acetyltransferase gene construct. This effect of OA was dose-dependent and promoter-specific and appeared to be attributable to inhibition of protein phosphatase 2A as opposed to protein phosphatase 1. The ability of OA to potentiate the heat-induced expression of pHBCAT appeared to be a feature common to several different cell types examined. We propose that the heat-induced transcriptional activation of heat shock genes is associated with the phosphorylation of component(s) of the transcription complex and that OA enhances this phosphorylation, thereby potentiating the heat-induced hsp 70 promoter activity.