Pfarr C M, Coue M, Grissom P M, Hays T S, Porter M E, McIntosh J R
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309.
Nature. 1990 May 17;345(6272):263-5. doi: 10.1038/345263a0.
Recent evidence suggests that the force for poleward movement of chromosomes during mitosis is generated at or close to the kinetochores. Chromosome movement depends on motion relative to microtubules, but the identities of the motors remain uncertain. One candidate for a mitotic motor is dynein, a large multimeric enzyme which can move along microtubules toward their slow growing end. Dyneins were originally found in axonemes of cilia and flagella where they power microtubule sliding. Recently, cytoplasmic dyneins have also been found, and specific antibodies have been raised against them. The cellular localization of dynein has previously been studied with several antibodies raised against flagellar dynein, but the relevance of these data to the distribution of cytoplasmic dynein is not known. Antibodies raised against cytoplasmic dyneins have shown localization of dynein antigens to the mitotic spindles in Caenorhabditis elegans embryos (Lye et al., personal communication) and punctate cytoplasmic structures in Dictyostelium amoebae. Using antibodies that recognize subunits of cytoplasmic dyneins, we show here that during mitosis, cytoplasmic dynein antigens concentrate near the kinetochores, centrosomes and spindle fibres of HeLa and PtK1 cells, whereas at interphase they are distributed throughout the cytoplasm. This is consistent with the hypothesis that cytoplasmic dynein is a mitotic motor.
最近有证据表明，有丝分裂期间染色体向极移动的力是在着丝粒处或其附近产生的。染色体的移动取决于相对于微管的运动，但驱动蛋白的身份仍不确定。有丝分裂驱动蛋白的一个候选者是动力蛋白，它是一种大型多聚酶，能够沿着微管向其生长缓慢的一端移动。动力蛋白最初是在纤毛和鞭毛的轴丝中发现的，在那里它们推动微管滑动。最近，也发现了细胞质动力蛋白，并制备了针对它们的特异性抗体。以前曾用几种针对鞭毛动力蛋白的抗体研究过动力蛋白在细胞内的定位，但这些数据与细胞质动力蛋白分布的相关性尚不清楚。针对细胞质动力蛋白产生的抗体已显示，在秀丽隐杆线虫胚胎中，动力蛋白抗原定位于有丝分裂纺锤体（Lye等人，个人交流），在盘基网柄菌变形虫中定位于点状细胞质结构。我们使用识别细胞质动力蛋白亚基的抗体表明，在有丝分裂期间，细胞质动力蛋白抗原集中在HeLa和PtK1细胞的着丝粒、中心体和纺锤体纤维附近，而在间期它们分布于整个细胞质中。这与细胞质动力蛋白是一种有丝分裂驱动蛋白的假说一致。
