MAD2蛋白在蚕豆细胞周期中的同源定位

细胞周期是一个高度有序的过程,其运行过程受到多个检验点(checkpoint)的严格监控.MAD2是动物细胞纺锤体检验点(spindle checkpoint)中一种重要的蛋白。我们利用免疫印记法从蚕豆组织中检测到一种MAD2的同源蛋白,该蛋白的分子量在26KD左右,其亚细胞分布方式与动物细胞大致相同,都随细胞周期的进行而变化:在间期细胞中,MAD2分布于整个细胞中,并且在核膜外侧有优先聚集;在有丝分裂前期细胞中,MAD2在核膜破裂后开始在动粒处聚集;到早中期(prometaphase),MAD2定位于动粒;随着微管的延伸,MAD2逐渐减少直至消失,在中期,晚中期及后期细胞中,动粒处已无MAD2的分布。

LOCOLIZATION OF MAD2 HOMOLOGUE IN Cell CYCLE OF VICIA FABA

Cell cycle is a highly ordered process, and it is tightly monitored by checkpoints . MAD 2 is an important protein of spindle checkpoint. We have identified a broad bean homologue of MAD 2 using imniunoblotting method. It has a MW of about 26kDa. The pattern of its localization in mitotic cells is almost like those homologues in animal cells, it also varies with the stage of mitosis. During interphase, MAD 2 was distributed throughout the cell and had a prominent localization in perinucleararea. After nuclear envelope broke down, it began accumulating on kinetochore. In prometaphase, MAD 2 colocalized with the kinetochores. With the extension of microtubule, the kinetochore was labeled weakly or not at all. By late metaphase and anaphase, Mad 2 was not detectable on kinetochores.