Nishijima J, Wright T M, Hoffman R D, Liao F, Symer D E, Shin H S
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Biochemistry. 1989 Apr 4;28(7):2902-9. doi: 10.1021/bi00433a023.
We have previously described the chemoattraction of lymphoblasts by lysophosphatidylcholine [Hoffman, R. D., et al. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 3285-3289]. In studying the mechanism of chemoattraction it was found that lysophosphatidylcholine was metabolized to 1,2-diacylglycerol by the lymphoblastic cell line 6C3HED. One route of metabolism involves the acylation of lysophosphatidylcholine to phosphatidylcholine with subsequent hydrolysis to 1,2-diacylglycerol and phosphocholine by the action of phospholipase C. The increase in cellular 1,2-diacylglycerol was established by metabolic experiments using [14C]glycerol-labeled lysophosphatidylcholine and by mass measurements of 1,2-diacylglycerol. The presence of a phosphatidylcholine-hydrolyzing phospholipase C was confirmed in 6C3HED cell homogenates. In intact cells, lysophosphatidylcholine induced a pattern of protein phosphorylation similar to those of 1,2-dioctanoylglycerol and phorbol 12-myristate 13-acetate, two known activators of protein kinase C. This pathway of lysophosphatidylcholine metabolism, which involves a phosphatidylcholine-hydrolyzing phospholipase C, may be important in the activation of protein kinase C independent of inositol phospholipid hydrolysis.
我们之前已经描述过溶血磷脂酰胆碱对淋巴母细胞的化学吸引作用[霍夫曼，R.D.等人（1982年）《美国国家科学院院刊》79卷，3285 - 3289页]。在研究化学吸引作用机制时发现，淋巴母细胞系6C3HED可将溶血磷脂酰胆碱代谢为1,2 - 二酰基甘油。一种代谢途径是溶血磷脂酰胆碱先酰化生成磷脂酰胆碱，随后在磷脂酶C的作用下水解为1,2 - 二酰基甘油和磷酸胆碱。通过使用[14C]甘油标记的溶血磷脂酰胆碱进行代谢实验以及对1,2 - 二酰基甘油进行质量测定，证实了细胞内1,2 - 二酰基甘油的增加。在6C3HED细胞匀浆中也证实了存在一种能水解磷脂酰胆碱的磷脂酶C。在完整细胞中，溶血磷脂酰胆碱诱导的蛋白质磷酸化模式与1,2 - 二辛酰甘油和佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯（两种已知的蛋白激酶C激活剂）相似。这种涉及能水解磷脂酰胆碱的磷脂酶C的溶血磷脂酰胆碱代谢途径，可能在不依赖肌醇磷脂水解的情况下对蛋白激酶C的激活起重要作用。
