Endoplasmic reticulum positioning and partitioning in mitotic HeLa cells
Endoplasmic reticulum positioning and partitioning in mitotic HeLa cells
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DOI：
10.1111/j.1469-7580.2005.00407.x
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发表时间：
2005-05-01
影响因子：
2.4
通讯作者：
Lucocq, J
中科院分区：
文献类型：
--
作者：
McCullough, S;Lucocq, J
细胞分裂用于将染色体和细胞器分配到两个子细胞中，但粗面内质网(RER)在动物细胞有丝分裂中分离的机制尚不清楚。在这里，我们研究了RER在有丝分裂的HeLa细胞中的分布及其与细胞骨架的关系。中期，粗面内质网位于细胞皮质，主要集中在两个部位。在质膜附近，RER与皮质肌动蛋白密切相关，经Latrunculin A处理后，RER元件回缩到皮质深层，变得更管状。因此，定位依赖于皮质F-肌动蛋白。在皮质更深处，脑池紧紧地包裹在纺锤体的轮廓上，并沿着靠近纺锤体极点的微管定向。体视学显示末期子代细胞的粗面内质网体积与细胞体积密切相关。这些结果表明，粗面内质网定位于中期皮质的外、内侧，与细胞骨架有关。这种排列与质膜深处同心层的排列相结合，似乎使粗面内质网在皮质中均匀分布，并有助于将大量粗面内质网和细胞成分结合在一起。
Cell division serves to distribute chromosomes and organelles into two daughter cells, but the mechanism of rough endoplasmic reticulum (RER) segregation in animal cell mitosis is poorly understood. Here we study the distribution of RER in mitotic HeLa cells and its relation to the cytoskeleton. At metaphase, the RER was located in the cell cortex and was most concentrated in two locations. Close to the plasma membrane the RER was closely associated with cortical actin, and after treatment with Latrunculin A RER elements retracted to the deep cortex and became more tubular. Positioning was therefore dependent on cortical F-actin. Deeper in the cortex cisternae were wrapped tightly around the contours of the spindle body and orientated along microtubules close the spindle poles. Stereology revealed a close correlation between RER volume and cell volume in telophase daughter cells. These results suggest that the RER is positioned at the outer and inner regions of metaphase cortex by association with cytoskeleton. This arrangement combined with a disposition in concentric layers, deep to the plasma membrane, appears to distribute the RER evenly in the cortex and may help to couple quantities of RER and cell constituents.