Winnefeld Marc, Rommelaere Jean, Cziepluch Celina
Infection and Cancer Department-F010 and Institut National de la Santé et de la Recherche Médicale U 375, Deutsches Krebsforschungszentrum, D-69120 Heidelberg, Germany.
Exp Cell Res. 2004 Feb 1;293(1):43-57. doi: 10.1016/j.yexcr.2003.09.028.
Eukaryotic organisms from yeast to human harbor genes encoding the small glutamine-rich tetratricopeptide repeat-containing (SGT) protein. Work presented here demonstrated the presence of human SGT (hSGT) protein in a panel of human cell lines and throughout the cell cycle. To identify cellular processes in which hSGT is involved, knock down populations were analyzed which were generated through transfection of hsgt-specific small interfering RNA. Most strikingly, depletion of hSGT led to reduced proliferation of the affected cell populations while the mitotic index was increased. Time-lapse video microscopy revealed that cells from hSGT-depleted populations were unable to complete cell division due to mitotic arrest which was frequently followed by cell death. Further evidence for a role in cell division was given by the accumulation of hSGT in the midzone and the midbody, and by a mitosis-specific migration pattern of hSGT as detected by Western blotting after SDS-PAGE or two-dimensional gel electrophoresis. In conclusion, results obtained in this study demonstrate that hSGT protein is a constitutive component of all human cell lines tested and that this protein is essential for successful completion of cell division.
从酵母到人类的真核生物都含有编码富含谷氨酰胺的小四肽重复序列（SGT）蛋白的基因。本文所展示的研究表明，在一组人类细胞系以及整个细胞周期中都存在人类SGT（hSGT）蛋白。为了确定hSGT参与的细胞过程，对通过转染hsgt特异性小干扰RNA产生的敲低群体进行了分析。最显著的是，hSGT的缺失导致受影响细胞群体的增殖减少，而有丝分裂指数增加。延时视频显微镜显示，来自hSGT缺失群体的细胞由于有丝分裂停滞而无法完成细胞分裂，随后常常发生细胞死亡。SDS-PAGE或二维凝胶电泳后通过蛋白质印迹法检测到hSGT在中间区和中间体的积累，以及hSGT的有丝分裂特异性迁移模式，这为其在细胞分裂中的作用提供了进一步证据。总之，本研究获得的结果表明，hSGT蛋白是所有测试的人类细胞系的组成成分，并且该蛋白对于细胞分裂的成功完成至关重要。
