Activation of human neutrophil NADPH oxidase by phosphatidic acid or diacylglycerol in a cell-free system - Activity of diacylglycerol is dependent on its conversion to phosphatidic acid
Activation of human neutrophil NADPH oxidase by phosphatidic acid or diacylglycerol in a cell-free system - Activity of diacylglycerol is dependent on its conversion to phosphatidic acid
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DOI：
10.1074/jbc.274.32.22243
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发表时间：
1999-08-06
影响因子：
4.8
通讯作者：
Curnutte, JT
中科院分区：
文献类型：
--
作者：
Erickson, RW;Langel-Peveri, P;Curnutte, JT
产生超氧化物的中性粒细胞NADPH氧化酶可以在无细胞重建系统中被几种激动剂激活，最著名的是花生四烯酸和洗涤剂十二烷基硫酸钠。在这项研究中，我们表明，磷脂酸和二酰基甘油可以分别作为有效的，生理激活剂的NADPH氧化酶在无细胞系统。这些脂质的超氧化物生成的刺激依赖于Mg 2+和激动剂的浓度。磷脂酸激活NADPH氧化酶似乎不需要磷脂酸磷酸水解酶将其转化为相应的二酰基甘油，因为二酰基甘油比磷脂酸激活系统慢得多，并且需要ATP的存在。证明二辛酰甘油对氧化酶的刺激是通过激活蛋白激酶C以外的方式。相反，二辛酰甘油转化为二辛酰磷脂酸的内源性二酰基甘油激酶存在于无细胞反应系统。这种转换是敏感的二酰基甘油激酶抑制剂R59949，并解释了显着较慢的动力学激活和新的ATP需求与二辛酰甘油。形成的二辛酰磷脂酸的水平对于NADPH氧化酶活化是次优的，但可以与未代谢的二辛酰甘油协同作用以活化超氧化物的产生。
The superoxide-generating neutrophil NADPH oxidase can be activated in cell-free reconstitution systems by several agonists, most notably arachidonic acid and the detergent sodium dodecyl sulfate. In this study, we show that both phosphatidic acids and diacylglycerols can serve separately as potent, physiologic activators of NADPH oxidase in a cell-free system. Stimulation of superoxide generation by these lipids was dependent upon both Mg2+ and agonist concentration. Activation of NADPH oxidase by phosphatidic acids did not appear to require their conversion to corresponding diacylglycerols by phosphatidate phosphohydrolase, since diacylglycerols were much slower than phosphatidic acids to activate the system and required the presence of ATP. Stimulation of the oxidase by dioctanoylglycerol proved to be by a means other than the activation of protein kinase C. Instead, dioctanoylglycerol was converted to dioctanoylphosphatidic acid by an endogenous diacylglycerol kinase present in the cell-free reaction system. This conversion was sensitive to the diacylglycerol kinase inhibitor R59949 and explains the markedly slower kinetics of activation and the novel ATP requirement seen with dioctanoylglycerol. The level of dioctanoylphosphatidic acid formed was suboptimal for NADPH oxidase activation but could synergize with the unmetabolized dioctanoylglycerol to activate superoxide generation.