Kinesin-1 and Cytoplasmic Dynein Act Sequentially to Move the Meiotic Spindle to the Oocyte Cortex in Caenorhabditis elegans
Kinesin-1 and Cytoplasmic Dynein Act Sequentially to Move the Meiotic Spindle to the Oocyte Cortex in Caenorhabditis elegans
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DOI：
10.1091/mbc.e08-12-1253
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发表时间：
2009-06-01
影响因子：
3.3
通讯作者：
McNally, Francis J.
中科院分区：
文献类型：
--
作者：
Ellefson, Marina L.;McNally, Francis J.
在动物雌性减数分裂期间，减数分裂纺锤体在后期通过一极附着于卵皮质，以允许选择性地处置极体中的一半染色体。在秀丽隐杆线虫中，这种后期纺锤体位置是通过驱动蛋白-1依赖的早期易位，随后是后期促进复合物（APC）依赖的纺锤体旋转依次实现的。部分耗尽细胞质动力蛋白重链的RNA干扰阻断纺锤体旋转，而不影响早期易位。动力蛋白耗竭也阻断了APC依赖的晚期易位，发生在驱动蛋白-1耗竭的胚胎。绿色荧光蛋白标记的动力蛋白重链的延时成像以及用动力蛋白特异性抗体的免疫荧光显示，动力蛋白在旋转或后期易位开始之前就开始在纺锤体极点积累。动力蛋白在两极的积累是驱动蛋白1独立和APC依赖，就像动力蛋白驱动的纺锤体运动。这代表了驱动蛋白-1/动力蛋白协调的情况，其中这两个极性相反的马达顺序且独立地作用于货物以使其沿相同方向移动。
During female meiosis in animals, the meiotic spindle is attached to the egg cortex by one pole during anaphase to allow selective disposal of half the chromosomes in a polar body. In Caenorhabditis elegans, this anaphase spindle position is achieved sequentially through kinesin-1-dependent early translocation followed by anaphase-promoting complex (APC)-dependent spindle rotation. Partial depletion of cytoplasmic dynein heavy chain by RNA interference blocked spindle rotation without affecting early translocation. Dynein depletion also blocked the APC-dependent late translocation that occurs in kinesin-1-depleted embryos. Time-lapse imaging of green fluorescent protein-tagged dynein heavy chain as well as immunofluorescence with dynein-specific antibodies revealed that dynein starts to accumulate at spindle poles just before the initiation of rotation or late translocation. Accumulation of dynein at poles was kinesin-1 independent and APC dependent, just like dynein driven spindle movements. This represents a case of kinesin-1/dynein coordination in which these two motors of opposite polarity act sequentially and independently on a cargo to move it in the same direction.