title: NSF/SNAPs and p97/p47/VCIP135 are sequentially required for cell cycle-dependent reformation of the ER network.
abstract: 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.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Kano
authors.forename: Hisao
authors.initials: H
authors.lastname: Kondo
authors.forename: Akitsugu
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Keiji
authors.initials: K
authors.lastname: Uchiyama
authors.forename: Nobuko
authors.initials: N
authors.lastname: Hosokawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nagata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Murata
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism / Q000502:physiology; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D016466:CHO Cells; D002453:Cell Cycle / Q000502:physiology*; D006224:Cricetinae; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism* / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008561:Membrane Fusion / Q000502:physiology; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008938:Mitosis; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology; D050765:Qa-SNARE Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D050600:SNARE Proteins / Q000378:metabolism
chemical_list: D000906:Antibodies; D009687:Nuclear Proteins; D050765:Qa-SNARE Proteins; D011993:Recombinant Fusion Proteins; D050600:SNARE Proteins; D049452:Green Fluorescent Proteins; D010450:Endopeptidases; C470473:Vcpip1 protein, rat; D000251:Adenosine Triphosphatases; C404942:p97 ATPase