Activation of phospholipase D by alpha-thrombin or epidermal growth factor contributes to the formation of phosphatidic acid, but not to observed increases in 1,2-diacylglycerol.
Activation of phospholipase D by alpha-thrombin or epidermal growth factor contributes to the formation of phosphatidic acid, but not to observed increases in 1,2-diacylglycerol.
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α-凝血酶或表皮生长因子对磷脂酶 D 的激活有助于磷脂酸的形成，但不会导致观察到的 1,2-二酰基甘油的增加。
DOI：
10.1042/bj2850395
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Raben,DM
中科院分区：
文献类型：
--
作者：
Wright,TM;Willenberger,S;Raben,DM
最近描述了受体介导的磷脂酰胆碱水解磷脂酶 D (PLD) 的激活。我们研究了 α-凝血酶和表皮生长因子 (EGF) 对细胞 PLD 活性的影响，以确定该酶在丝裂原诱导的磷脂酸和 sn-1,2-二酰基甘油增加中的作用。在乙醇存在的情况下，用α-凝血酶或EGF刺激[3H]肉豆蔻酸标记的静态IIC9细胞导致放射性标记的磷脂酰乙醇快速增加，并在1分钟时达到平台，表明PLD快速且短暂地激活。我们观察到放射性标记的磷脂酸的有丝分裂原刺激的增加同时减少。相反，乙醇对α-凝血酶或EGF刺激的sn-1,2-二酰基甘油水平的升高没有显着影响，这通过测量sn-1,2-二酰基甘油质量或[3H]1,2-二酰基甘油的出现来确定。通过二维薄层色谱检测到的一种新型脂质分析结果是在乙醇存在下用α-凝血酶而非EGF刺激的[3H]肉豆蔻酸标记细胞中产生的。在乙醇存在下，用PLD对从[3H]肉豆蔻酸标记的培养物中分离出的细胞脂质进行体外处理，也导致了这种新型脂质种类的产生，支持了这种酶在其生产中的作用。这些数据表明，在静止的 IIC9 细胞中： (a) α-凝血酶或 EGF 快速且短暂地激活 PLD； (b)虽然这种激活是促细胞分裂原诱导的磷脂酸增加的部分原因，但它对诱导的sn-1,2-二酰基甘油的增加没有贡献； (c)这种酶的激活似乎参与了IIC9成纤维细胞中响应α-凝血酶而不是EGF而产生的新型脂质的形成。
The receptor-mediated activation of a phosphatidylcholine-hydrolysing phospholipase D (PLD) has recently been described. We investigated the effect of alpha-thrombin and epidermal growth factor (EGF) on cellular PLD activity in order to determine the role of this enzyme in mitogen-induced increases in phosphatidic acid and sn-1,2-diacylglycerol. In the presence of ethanol, stimulation of [3H]myristic acid-labelled quiescent IIC9 cells with alpha-thrombin or EGF resulted in a rapid increase in radiolabelled phosphatidyl-ethanol which reached a plateau at 1 min, indicating the rapid and transient activation of PLD. We observed a concomitant decrease in the mitogen-stimulated increase of radiolabelled phosphatidic acid. In contrast, ethanol did not significantly effect the elevation of sn-1,2-diacylglycerol levels stimulated by alpha-thrombin or EGF as determined by measurement of sn-1,2-diacylglycerol mass or the appearance of [3H]1,2-diacylglycerol. A novel lipid, detected by two-dimensional t.l.c. analysis, was generated in [3H]myristic acid-labelled cells stimulated with alpha-thrombin, but not EGF, in the presence of ethanol. Treatment in vitro of cellular lipids isolated from [3H]myristic acid-labelled cultures with PLD in the presence of ethanol also resulted in the generation of this novel lipid species, supporting the role of this enzyme in its production. These data indicate that in quiescent IIC9 cells: (a) alpha-thrombin or EGF rapidly and transiently activates a PLD; (b) although this activation is responsible for part of the mitogen-induced increases in phosphatidic acid, it does not contribute to induced increases in sn-1,2-diacylglycerol; and (c) activation of this enzyme appears to be involved in the formation of a novel lipid generated in response to alpha-thrombin, but not EGF, in IIC9 fibroblasts.