White J R, Huang C K, Hill J M, Naccache P H, Becker E L, Sha'afi R I
J Biol Chem. 1984 Jul 10;259(13):8605-11.
The co-carcinogenic compound phorbol 12-myristate 13-acetate but not its inactive analogue 4 alpha-phorbol 12,13-didecanoate causes the phosphorylation of several rabbit neutrophil polypeptides whose molecular weights and isoelectric points (pI) are as follows: Mr = 40,000, pI = 6.4; Mr = 50,000, pI = 4.9; Mr = 55,000, pI = 6.3; Mr = 64,000, pI = 6.0; Mr = 70,000, pI = 5.6; Mr = 90,000, pI = 6.0. Most of these phosphorylated proteins are located exclusively in the cytosol; the 64,000 molecular weight protein is found both in the cytosol and the cytoskeleton, and the 40,000 molecular weight protein is found in the nuclear pellet. The 50,000 molecular weight protein is also phosphorylated in whole cells by the chemotactic peptide fMet-Leu-Phe and in cell-free systems by protein kinase C. Using limited proteolysis, one phosphopeptide fragment was phosphorylated by the three stimuli. In addition, phorbol 12-myristate 13-acetate but not 4 alpha-phorbol 12,13-didecanoate causes cell aggregation and the exocytotic release of the specific granules of rabbit neutrophils. In contrast, both compounds increase the amount of actin associated with the cytoskeleton. The divalent cation ionophore A23187 at low concentration and the compound phorbol 12-myristate 13-acetate act synergistically in causing neutrophil degranulation. Lysosomal enzyme release and the phosphorylation of the 50,000 molecular weight polypeptide produced by phorbl 12-myristate 13-acetate are inhibited by trifluoperazine, and these two responses seem to be causally related. These results are discussed in terms of the role of 1,2-diacylglycerol and activation of protein kinase C in specific granule release from rabbit neutrophils.
促癌化合物佛波醇12 -肉豆蔻酸酯13 -乙酸酯而非其无活性类似物4α-佛波醇12,13 -二十二烷酸酯可使几种兔中性粒细胞多肽发生磷酸化，这些多肽的分子量和等电点（pI）如下：Mr = 40,000，pI = 6.4；Mr = 50,000，pI = 4.9；Mr = 55,000，pI = 6.3；Mr = 64,000，pI = 6.0；Mr = 70,000，pI = 5.6；Mr = 90,000，pI = 6.0。这些磷酸化蛋白大多仅存在于细胞质中；分子量为64,000的蛋白在细胞质和细胞骨架中均有发现，分子量为40,000的蛋白则存在于细胞核沉淀中。分子量为50,000的蛋白在完整细胞中也会被趋化肽fMet - Leu - Phe磷酸化，在无细胞体系中会被蛋白激酶C磷酸化。通过有限的蛋白水解作用，一个磷酸肽片段会被这三种刺激物磷酸化。此外，佛波醇12 -肉豆蔻酸酯13 -乙酸酯而非4α-佛波醇12,13 -二十二烷酸酯会导致兔中性粒细胞聚集以及特异性颗粒的胞吐释放。相反，这两种化合物都会增加与细胞骨架相关的肌动蛋白量。低浓度的二价阳离子载体A23187与化合物佛波醇12 -肉豆蔻酸酯13 -乙酸酯在引起中性粒细胞脱颗粒方面具有协同作用。三氟拉嗪可抑制佛波醇12 -肉豆蔻酸酯13 -乙酸酯诱导的溶酶体酶释放以及分子量为50,000的多肽的磷酸化，这两种反应似乎存在因果关系。本文根据1,2 -二酰基甘油的作用以及蛋白激酶C的激活在兔中性粒细胞特异性颗粒释放中的作用对这些结果进行了讨论。
