Fujii J, Nakata T, Miyoshi E, Ikeda Y, Taniguchi N
Department of Biochemistry, Osaka University Medical School, Japan.
Biochem J. 1994 Jul 1;301 ( Pt 1)(Pt 1):31-4. doi: 10.1042/bj3010031.
We have reported that the phorbol ester phorbol 12-myristate 13-acetate (PMA) enhances the expression of manganese superoxide dismutase (Mn-SOD) mRNA [Fujii and Taniguchi (1991) J. Biol. Chem. 266, 23,142-23,146]. Okadaic acid, an inhibitor of type I and type IIa phosphatases, was also found to induce Mn-SOD mRNA at submicromolar concentrations in HeLa cells. Addition of cycloheximide resulted in superinduction of PMA- or tumour necrosis factor-stimulated expression of the mRNA, but not of okadaic acid-stimulated expression. When the effect of cycloheximide on the decay of Mn-SOD mRNA was examined by inhibiting mRNA synthesis with actinomycin D, cycloheximide had virtually no effect on mRNA stability, suggesting that accumulation of the mRNA was caused by activation by this reagent of transcription of the gene. PMA pretreatment of HeLa cells markedly enhanced cycloheximide-dependent superinduction of Mn-SOD mRNA. These data suggest that phosphorylation of several proteins is implicated in the regulation of Mn-SOD gene expression.
我们已经报道，佛波酯佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯（PMA）可增强锰超氧化物歧化酶（Mn-SOD）mRNA的表达[藤井和谷口（1991年）《生物化学杂志》266, 23142 - 23146]。冈田酸是I型和IIa型磷酸酶的抑制剂，在亚微摩尔浓度下也被发现可在HeLa细胞中诱导Mn-SOD mRNA。添加放线菌酮导致PMA或肿瘤坏死因子刺激的mRNA表达超诱导，但对冈田酸刺激的表达无此作用。当通过用放线菌素D抑制mRNA合成来检测放线菌酮对Mn-SOD mRNA降解的影响时，放线菌酮对mRNA稳定性几乎没有影响，这表明mRNA的积累是由该试剂激活基因转录所致。HeLa细胞的PMA预处理显著增强了放线菌酮依赖性的Mn-SOD mRNA超诱导。这些数据表明几种蛋白质的磷酸化与Mn-SOD基因表达的调控有关。
