Endo Y, Komatsu S, Hirai M, Shimizu N, Suzuki S
Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
J In Vitro Fert Embryo Transf. 1991 Jun;8(3):160-6. doi: 10.1007/BF01131708.
The treatment of mouse eggs with phorbol esters and diacylglycerol inhibits sperm penetration and results in biochemical modification of the zona pellucida. In this report, we have demonstrated the presence of protein kinase C (PKC) activity in mouse eggs as determined by 12-O-tetradecanoyl phorbol-13-acetate (TPA) dependent in vivo and in vitro protein phosphorylation in mouse eggs. When mouse eggs were radiolabeled with [32P]phosphate and treated with TPA, two specific proteins, 70 and 20 kDa, were phosphorylated. The 70-kDa protein was also phosphorylated in vitro by endogenous PKC. In addition, we have shown that exogenous PKC induced the in vitro phosphorylation of 70-, 55-, and 20-kDa proteins in egg extract. The 70-kDa protein was also phosphorylated in vitro after treatment of the cytosol fraction of mouse eggs with TPA, suggesting that this protein might be a specific substrate for PKC and that it is located in the cytosol. These results demonstrate that mouse eggs contain PKC activity and suggest that PKC-catalyzed protein phosphorylation of specific proteins might be involved in the regulation of egg-induced modification of the zona pellucida.
用佛波酯和二酰基甘油处理小鼠卵子会抑制精子穿透，并导致透明带的生化修饰。在本报告中，我们通过12-O-十四酰佛波醇-13-乙酸酯（TPA）依赖的小鼠卵子体内和体外蛋白质磷酸化，证明了小鼠卵子中存在蛋白激酶C（PKC）活性。当用[32P]磷酸盐对小鼠卵子进行放射性标记并用TPA处理时，两种特定蛋白质，即70 kDa和20 kDa的蛋白质被磷酸化。70 kDa的蛋白质在体外也被内源性PKC磷酸化。此外，我们还表明，外源性PKC诱导了卵子提取物中70 kDa、55 kDa和20 kDa蛋白质的体外磷酸化。在用TPA处理小鼠卵子的胞质部分后，70 kDa的蛋白质在体外也被磷酸化，这表明该蛋白质可能是PKC的特异性底物，并且它位于胞质溶胶中。这些结果表明小鼠卵子含有PKC活性，并表明PKC催化的特定蛋白质的蛋白质磷酸化可能参与卵子诱导的透明带修饰的调节。
