Progressive sheet-to-tubule transformation is a general mechanism for endoplasmic reticulum partitioning in dividing mammalian cells.
Progressive sheet-to-tubule transformation is a general mechanism for endoplasmic reticulum partitioning in dividing mammalian cells.
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DOI：
10.1091/mbc.e10-12-0950
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发表时间：
2012-07
影响因子：
3.3
通讯作者：
Jokitalo E
中科院分区：
文献类型：
--
作者：
Puhka M;Joensuu M;Vihinen H;Belevich I;Jokitalo E
在有丝分裂期间，ER网络重组可导致ER在细胞皮质处包装成紧密的同心层，并且与细胞的变圆串联发生。形态测量和3D EM分析表明，除了重组，ER片在哺乳动物细胞的后期之前经历向更多的有孔和管状形式的转化。内质网（ER）结构和功能都很复杂，由相互连接的片层和小管组成的动态网络。为了更全面地了解间期和有丝分裂细胞中的ER组织，并解决该领域的差异（即，在有丝分裂过程中，ER片层是持续存在还是转化为小管），我们使用活细胞成像、高分辨率电子显微镜和三维电子显微镜分析了四种不同哺乳动物细胞系中的ER。在间期细胞中，我们发现不同细胞系之间的网络组织和片层结构存在很大差异。在有丝分裂细胞中，我们发现ER经历了空间重组和结构转变的床单朝向更多的开窗和管状形式。然而，空间重组和片-小管转化的程度在细胞系中不同。内质网的开窗和微管与膜结合核糖体数量的减少相关。
During mitosis, ER network reorganization can lead to packing of the ER into tight concentric layers at the cell cortex and occurs in tandem with rounding of the cell. Morphometric and 3D EM analysis shows that in addition to reorganization, ER sheets undergo transformation toward more fenestrated and tubular forms before anaphase in mammalian cells. The endoplasmic reticulum (ER) is both structurally and functionally complex, consisting of a dynamic network of interconnected sheets and tubules. To achieve a more comprehensive view of ER organization in interphase and mitotic cells and to address a discrepancy in the field (i.e., whether ER sheets persist, or are transformed to tubules, during mitosis), we analyzed the ER in four different mammalian cell lines using live-cell imaging, high-resolution electron microscopy, and three dimensional electron microscopy. In interphase cells, we found great variation in network organization and sheet structures among different cell lines. In mitotic cells, we show that the ER undergoes both spatial reorganization and structural transformation of sheets toward more fenestrated and tubular forms. However, the extent of spatial reorganization and sheet-to-tubule transformation varies among cell lines. Fenestration and tubulation of the ER correlates with a reduced number of membrane-bound ribosomes.