CHARACTERIZATION OF THE SIGNAL-TRANSDUCTION OF PROSTAGLANDIN-E RECEPTOR EP1 SUBTYPE IN CDNA-TRANSFECTED CHINESE-HAMSTER OVARY CELLS
CHARACTERIZATION OF THE SIGNAL-TRANSDUCTION OF PROSTAGLANDIN-E RECEPTOR EP1 SUBTYPE IN CDNA-TRANSFECTED CHINESE-HAMSTER OVARY CELLS
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DOI：
10.1016/0304-4165(94)00182-w
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发表时间：
1995-05-11
影响因子：
3
通讯作者：
NEGISHI, M
中科院分区：
文献类型：
--
作者：
KATOH, H;WATABE, A;NEGISHI, M
我们研究了小鼠前列腺素E受体EP 1亚型的信号转导使用中国仓鼠卵巢细胞稳定表达克隆的EP 1。EP 1激动剂磺前列酮诱导表达EP 1的细胞内Ca 2+浓度迅速增加。大部分的增加被取消细胞外Ca 2+的去除，是不敏感的U-73122，磷脂酶C抑制剂。磺前列酮刺激磷脂酰肌醇水解，但这种刺激被取消细胞外Ca 2+的去除，表明EP 1刺激的磷脂酰肌醇水解是细胞外Ca 2+内流的结果。因此，EP 1的信号转导是通过独立于磷脂酶C激活的途径的细胞外Ca 2+进入。我们进一步研究了具有蛋白激酶C或蛋白激酶A的潜在磷酸化位点的EP 1的信号转导的调节。短期暴露的细胞12-O-十四烷酰佛波醇13-乙酸酯（TPA）完全抑制了磺前列酮诱导的细胞内Ca 2+浓度的增加，而毛喉素或二丁酰cAMP没有影响它，这表明蛋白激酶C，而不是蛋白激酶A参与调节的EP 1信号转导。此外，由于EP 1 mRNA水平的降低，长期暴露于TPA降低了EP 1的PGE（2）结合活性。蛋白激酶C诱导EP 1的短期和长期脱敏。
We examined the signal transduction of mouse prostaglandin E receptor EP1 subtype using Chinese hamster ovary cells stably expressing the cloned EP1. Sulprostone, an EP1 agonist, induced a rapid increase in intracellular Ca2+ concentration in the EP1-expressing cells. Most of the increase was abolished by removal of extracellular Ca2+, and was insensitive to U-73122, a phospholipase C inhibitor. Sulprostone stimulated phosphatidylinositol hydrolysis, but this stimulation was abolished by removal of extracellular Ca2+, indicating that EP1-stimulated phosphatidylinositol hydrolysis is the result of extracellular Ca2+ influx. Thus, the signal transduction of EP1 is extracellular Ca2+ entry through a pathway independent of phospholipase C activation. We further examined the regulation of the signal transduction of EP1 having potential phosphorylation sites for either protein kinase C or protein kinase A. Short-term exposure of the cells to 12-O-tetradecanoylphorbol 13-acetate (TPA) completely suppressed the sulprostone-induced increase in intracellular Ca2+ concentration, while forskolin or dibutyryl cAMP did not affect it, suggesting that protein kinase C but not protein kinase A is involved in the regulation of the EP1 signal transduction. Furthermore, long-term exposure to TPA decreased PGE(2) binding activity of EP1 due to the reduction of the EP1 mRNA level. Protein kinase C induces short- and long-term desensitization of EP1.