神经节苷脂GM_3对人白血病J6-2细胞PKC转位及DAG含量的影响

应用SDS PAGE及Western印迹技术检测神经节苷脂GM3 处理前后人白血病J6 2细胞不同类型PKC在细胞内的转位情况 ,同时利用高效薄板层析技术观察了细胞内DAG含量的变化 ,从而探讨GM3 抑制PKC活性的机制 .实验发现 ,GM3 处理后胞液PKCα明显增加 ,而颗粒结合PKCα则相对减少 ;GM3 对其它亚型PKC在细胞内分布无显著影响 .同时还发现 ,GM3 处理后细胞内DAG含量降低 (P <0 0 5 ) .结果表明 ,GM3 抑制PKCα由胞浆向质膜转位 ,对其它亚型PKC在细胞内转位无影响 .提示GM3 抑制的PKC亚型可能是PKCα .同时GM3 降低细胞内DAG含量 ,这可能与GM3抑制PKCα活性机制有关

Effects of Ganglioside GM_3 on the Translocation of PKC and the Content of DAG in Human Leukemia J6-2 Cell Line

To understand the mechanism of ganglioside GM 3 effecting on protein kinase C (PKC), the translocation of PKC isoforms in J6 2 cells and the content of diacylglycerol (DAG) was compared between cells treated with GM 3 and control cells. The results showed that the content of PKCα in the cytosol of J6 2 cells treated with GM 3 was higher than that of control cells, whereas the content of PKCα conjugated with plasma membrane was lower than that of control cells. GM 3 had no effect on the contents of other PKC isoforms in the cytosol and the plasma membrane. The content of DAG of J6 2 Cells treated with GM 3 was lower than that of control cells. The results suggested that GM 3 inhibited the PKCα translocation from the cytosol to the plasma membrane, and signified that the kind of PKC isoform inhibited by GM 3 was PKCα. The inhibitory mechanism of GM 3 on PKCα was related to the decreasing content of DAG.