PKCα translocation from mitochondria to nucleus is closely related to induction of apoptosis in gastric cancer cells

PKCs have been implicated in the regulation of cellular differentiation, proliferation, apoptosis and signal transduction. It was demonstrated in this study that PKCα was located both at mitochondria and in cytosol in gastric cancer cell line BGC-823. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in the translocation of PKCα from both mitochondria and cytosol to nucleus as clearly shown by laserscanningconfocal microscopy, while the protein level of PKCα was not changed by TPA treatment as detected by Western blot. The results also revealed that TPA-induced translocation of PKCα was in close association with apoptosis induction, and such association was further affirmed by other experiments where various apoptotic stimuli and specific inhibitors of PKC were used. Taken together, these findings indicate that translocation of PKCα from both mitochondria and cytosol to nucleus in gastric cancer cell is accompanied by induction of apoptosis, and may imply a new mechanism of the potential linking between cell apoptosis and PKCα translocation.     

PKCα translocation from mitochondria to nucleus is closely related to induction of apoptosis in gastric cancer cells

PKCs have been implicated in the regulation of cellular differentiation, proliferation, apoptosis and signal transduction. It was demonstrated in this study that PKCa was located both at mitochondria and in cytosol in gastric cancer cell line BGC-823. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in the translocation of PKCa from both mitochondria and cytosol to nucleus as clearly shown by laser-scanning-confocal microscopy, while the protein level of PKCa was not changed by TPA treatment as detected by Western blot. The results also revealed that TPA-induced translocation of PKCa was in close association with apoptosis induction, and such association was further affirmed by other experiments where various apoptotic stimuli and specific inhibitors of PKC were used. Taken together, these findings indicate that translocation of PKCa from both mitochondria and cytosol to nucleus in gastric cancer cell is accompanied by induction of apoptosis, and may imply a new mechanism of th     

PKCα 由线粒体向细胞核转运与胃癌细胞凋亡诱导密切相关

PKC在细胞生长、分化、凋亡和信号转导调节中具有重要作用.通过激光扫描共聚焦显微镜证实:在胃癌BGC-823细胞中,一部分PKCα 定位于线粒体,一部分定位在胞浆,细胞经TPA处理后,位于线粒体和胞浆的PKCα 向细胞核转运;Western blot检测则发现PKCα 蛋白表达水平在TPA处理前后没有发生变化.此外,应用凋亡诱导剂和特异性PKC抑制剂的实验结果进一步证实:胃癌细胞内PKCα由线粒体和胞浆向细胞核转运与细胞凋亡的诱导密切相关.提示PKCα在细胞内的定向转运可能是与细胞凋亡过程相关联的重要事件之一.     

类泛素蛋白--SUMO

SUMO(small ubiquitin-related modifier)是泛素(ubiquitin)类蛋白家族的重要成员之一。尽管SUMO的生化反应途径与泛素相似,但不像泛素那样诱导底物蛋白降解。SUMO化能够使蛋白质更加稳定,进而调节许多关键的细胞活动。现从分类、结构、生化途径和生物学功能等方面介绍SUMO及SUMO化过程。