Protein kinase A and protein kinase C signaling pathway interaction in phenylethanolamine N-methyltransferase gene regulation
Protein kinase A and protein kinase C signaling pathway interaction in phenylethanolamine N-methyltransferase gene regulation
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DOI：
10.1046/j.1471-4159.2003.01728.x
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发表时间：
2003-05-01
影响因子：
4.7
通讯作者：
Wong, DL
中科院分区：
文献类型：
--
作者：
Tai, TC;Wong, DL
蛋白激酶A（PKA）和蛋白激酶C（PKC）信号通路在调节PC 12细胞中苯乙醇胺N -甲基转移酶（PNMT）启动子驱动的基因转录中相互作用。用大鼠PNMT启动子-荧光素酶报告基因构建体pGL 3RP 893转染的细胞的毛喉素处理使启动子活性增加约两倍，而佛波醇-12-肉豆蔻酸酯-13乙酸酯（PMA）处理没有影响。然而，同时毛喉素和PMA治疗协同激活PNMT启动子约4倍，这表明PKC刺激需要事先诱导PKA通路。与这种可能性相一致的是，腺苷酸环化酶抑制剂MDL 12，330 A和PKA抑制剂H-89通过毛喉素和PMA的组合阻止PNMT启动子刺激。PKA和PKC的调节似乎部分介导的Egr-1和Sp1通过其共识元件在PNMT启动子。Forskolin和PMA处理的PC 12细胞增加Egr-1蛋白和磷酸化Egr-1/DNA结合复合物的形成在相同程度上，但只增加磷酸化Sp1/DNA结合复合物的形成，而不改变Sp1蛋白水平。突变的-165 bp Egr-1和-48 bp Sp1位点，分别减弱和废除联合毛喉素和PMA介导的启动子激活。PNMT启动子分析进一步表明，PKA和PKC的协同刺激涉及-442和-392 bp之间的DNA序列，并可能在该区域内的GCM结合元件。
The protein kinase A (PKA) and protein kinase C (PKC) signaling pathways appear to interact in regulating phenylethanolamine N -methyltransferase (PNMT) promoter-driven gene transcription in PC12 cells. Forskolin treatment of cells transfected with the rat PNMT promoter-luciferase reporter gene construct pGL3RP893 increased promoter activity approximately two-fold whereas phorbol-12-myristate-13 acetate (PMA) treatment had no effect. However, simultaneous forskolin and PMA treatment synergistically activated the PNMT promoter approximately four-fold, suggesting that PKC stimulation requires prior induction of the PKA pathway. Consistent with this possibility the adenylate cyclase inhibitor MDL12,330A, and the PKA inhibitor H-89 prevented PNMT promoter stimulation by the combination of forskolin and PMA. PKA and PKC regulation seems to be mediated in part by Egr-1 and Sp1 through their consensus elements in the PNMT promoter. Forskolin and PMA treatment of PC12 cells increased Egr-1 protein and phosphorylated Egr-1/DNA-binding complex formation to the same extent but only increased phosphorylated Sp1/DNA binding complex formation without altering Sp1 protein levels. Mutation of the - 165 bp Egr-1 and - 48 bp Sp1 sites, respectively, attenuated and abolished combined forskolin and PMA-mediated promoter activation. PNMT promoter analysis further showed that synergistic stimulation by PKA and PKC involves DNA sequences between - 442 and - 392 bp, and potentially a GCM binding element lying within this region.