title: Mitotic phosphorylation of VCIP135 blocks p97ATPase-mediated Golgi membrane fusion.
abstract: In mammals, the Golgi apparatus is disassembled early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 and p37 phosphorylation on Serine-56 and Threonine-59 result in mitotic inhibition of the p97/p47 and the p97/p37 pathways, respectively [11,14]. In this study, we show another mechanism of mitotic inhibition of p97-mediated Golgi membrane fusion. We clarified that VCIP135, an essential factor in both p97 membrane fusion pathways, is phosphorylated on Threonine-760 and Serine-767 by Cdc2 at mitosis and that this phosphorylated VCIP135 does not bind to p97. An in vitro Golgi reassembly assay revealed that VCIP135(T760E, S767E), which mimics mitotic phosphorylation, caused no cisternal regrowth. Our results indicate that the phosphorylation of VCIP135 on Threonine-760 and Serine-767 inhibits p97-mediated Golgi membrane fusion at mitosis.
authors.affiliation: Department of Molecular Cell Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Totsukawa
authors.forename: Ayaka
authors.initials: A
authors.lastname: Matsuo
authors.forename: Ayano
authors.initials: A
authors.lastname: Kubota
authors.forename: Yuya
authors.initials: Y
authors.lastname: Taguchi
authors.forename: Hisao
authors.initials: H
authors.lastname: Kondo
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008561:Membrane Fusion / Q000502:physiology*; D008938:Mitosis; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; D013912:Threonine; D012694:Serine; D010450:Endopeptidases; C581414:VCPIP1 protein, human; D000251:Adenosine Triphosphatases; C404942:p97 ATPase