title: Self-organization of core Golgi material is independent of COPII-mediated endoplasmic reticulum export.
abstract: The Golgi is a highly organized and dynamic organelle that receives and distributes material from and to the endoplasmic reticulum (ER) and the endocytic pathway. One open question about Golgi organization is whether it is solely based on ER-to-Golgi transport. Here, we analyzed the kinetics of Golgi breakdown in the absence of COPII-dependent ER export with high temporal and spatial resolution using quantitative fluorescence microscopy. We found that Golgi breakdown occurred in two phases. While Golgi enzymes continuously redistributed to the ER, we consistently observed extensive Golgi fragmentation at the beginning of the breakdown, followed by microtubule-dependent formation of a Golgi remnant structure (phase 1). Further Golgi disintegration occurred less uniformly (phase 2). Remarkably, cisternal Golgi morphology was lost early in phase 1 and Golgi fragments instead corresponded to variably sized vesicle clusters. These breakdown intermediates were devoid of COPI-dependent recycling material, but contained typical 'core' Golgi components. Furthermore, Golgi breakdown intermediates were able to disassemble and reassemble following cell division, indicating that they retained important regulatory capabilities. Taken together, these findings support the view that Golgi self-organization exists independently of ER-to-Golgi transport.
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Institute of Cell Dynamics and Imaging, University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany Cells in Motion Cluster of Excellence (EXC1003-CiM), University of Muenster, von-Esmarch-Str. 56, 48149 Muenster, Germany cschuber@uni-muenster.de.
authors.forename: Christian E
authors.initials: CE
authors.lastname: Schuberth
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Carolina
authors.initials: C
authors.lastname: Tängemo
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Cvetalina
authors.initials: C
authors.lastname: Coneva
authors.affiliation: Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Tischer
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany Advanced Light Microscopy Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Pepperkok
mesh_terms: D022181:COP-Coated Vesicles / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D021381:Protein Transport; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D033921:Vesicular Transport Proteins
keywords: Golgi dynamics; Live-cell imaging; Sar1; Secretory pathway