title: Sequential depletion and acquisition of proteins during Golgi stack disassembly and reformation.
abstract: Herein, we report the stepwise transport of multiple plant Golgi membrane markers during disassembly of the Golgi apparatus in tobacco leaf epidermal cells in response to the induced expression of the GTP-locked Sar1p or Brefeldin A (BFA), and reassembly on BFA washout. The distribution of fluorescent Golgi-resident N-glycan processing enzymes and matrix proteins (golgins) with specific cis-trans-Golgi sub-locations was followed by confocal microscopy during disassembly and reassembly. The first event during Golgi disassembly was the loss of trans-Golgi enzymes and golgins from Golgi membranes, followed by a sequential redistribution of medial and cis-Golgi enzymes into the endoplasmic reticulum (ER), whilst golgins were relocated to the ER or cytoplasm. This event was confirmed by fractionation and immuno-blotting. The sequential redistribution of Golgi components in a trans-cis sequence may highlight a novel retrograde trafficking pathway between the trans-Golgi and the ER in plants. Release of Golgi markers from the ER upon BFA washout occurred in the opposite sequence, with cis-matrix proteins labelling Golgi-like structures before cis/medial enzymes. Trans-enzyme location was preceded by trans-matrix proteins being recruited back to Golgi membranes. Our results show that Golgi disassembly and reassembly occur in a highly ordered fashion in plants.
authors: Department of Applied Genetics and Cell Biology, University of Natural Resources and Applied Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria.
authors: Jennifer
authors: J
authors: Schoberer
authors: John
authors: J
authors: Runions
authors: Herta
authors: H
authors: Steinkellner
authors: Richard
authors: R
authors: Strasser
authors: Chris
authors: C
authors: Hawes
authors: Anne
authors: A
authors: Osterrieder
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D020126:Brefeldin A / Q000494:pharmacology; D000078404:Epidermal Cells; D006056:Golgi Apparatus / Q000187:drug effects / Q000502:physiology*; D018613:Microscopy, Confocal; D001678:Organelle Biogenesis; D018515:Plant Leaves / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D014026:Nicotiana / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D011500:Protein Synthesis Inhibitors; D020126:Brefeldin A