Kano Fumi, Kondo Hisao, Yamamoto Akitsugu, Kaneko Yayoi, Uchiyama Keiji, Hosokawa Nobuko, Nagata Kazuhiro, Murata Masayuki
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
Genes Cells. 2005 Oct;10(10):989-99. doi: 10.1111/j.1365-2443.2005.00894.x.
The endoplasmic reticulum (ER) has a characteristic polygonal structure with hallmark three-way junctions. In a previous paper, we reconstituted the disruption of the pre-existing ER network using mitotic cytosol from HeLa cells in streptolysin O (SLO)-permeabilized CHO-HSP cells (stably expressing GFP-HSP47). In addition, we found that interphase cytosol induced reformation of the disrupted ER network into a continuous network structure. Here, we show that the reformation of the ER network is accomplished through two sequential fusion reactions. The first process is mediated by NSF/alpha and gamma-SNAPs, and involves the generation of typical membranous intermediate structures that connect the disrupted ER tubules. A subsequent fusion is mediated by p97/p47/VCIP135, which has been shown to be required for homotypic fusion events in Golgi cisternae regrowth after mitosis. In addition, we also found that both fusion processes involve the t-SNARE, syntaxin 18.
内质网（ER）具有特征性的多边形结构及标志性的三岔连接。在之前的一篇论文中，我们利用来自HeLa细胞的有丝分裂胞质溶胶，在经链球菌溶血素O（SLO）通透处理的CHO-HSP细胞（稳定表达GFP-HSP47）中重建了预先存在的内质网网络的破坏。此外，我们发现间期胞质溶胶可诱导破坏的内质网网络重新形成连续的网络结构。在此，我们表明内质网网络的重新形成是通过两个连续的融合反应完成的。第一个过程由NSF/α和γ-SNAP介导，涉及生成连接被破坏的内质网小管的典型膜性中间结构。随后的融合由p97/p47/VCIP135介导，这已被证明在有丝分裂后高尔基体潴泡再生的同型融合事件中是必需的。此外，我们还发现这两个融合过程都涉及t-SNARE即Syntaxin 18。
