title: Capacity of the Golgi apparatus for cargo transport prior to complete assembly.
abstract: In yeast, particular emphasis has been given to endoplasmic reticulum (ER)-derived, cisternal maturation models of Golgi assembly while in mammalian cells more emphasis has been given to golgins as a potentially stable assembly framework. In the case of de novo Golgi formation from the ER after brefeldin A/H89 washout in HeLa cells, we found that scattered, golgin-enriched, structures formed early and contained golgins including giantin, ranging across the entire cis to trans spectrum of the Golgi apparatus. These structures were incompetent in VSV-G cargo transport. Second, we compared Golgi competence in cargo transport to the kinetics of addition of various glycosyltransferases and glycosidases into nascent, golgin-enriched structures after drug washout. Enzyme accumulation was sequential with trans and then medial glycosyltransferases/glycosidases found in the scattered, nascent Golgi. Involvement in cargo transport preceded full accumulation of enzymes or GPP130 into nascent Golgi. Third, during mitosis, we found that the formation of a golgin-positive acceptor compartment in early telophase preceded the accumulation of a Golgi glycosyltransferase in nascent Golgi structures. We conclude that during mammalian Golgi assembly components fit into a dynamic, first-formed, multigolgin-enriched framework that is initially cargo transport incompetent. Resumption of cargo transport precedes full Golgi assembly.
authors.affiliation: Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
authors.forename: Shu
authors.initials: S
authors.lastname: Jiang
authors.forename: Sung W
authors.initials: SW
authors.lastname: Rhee
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gleeson
authors.forename: Brian
authors.initials: B
authors.lastname: Storrie
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D020126:Brefeldin A / Q000494:pharmacology; D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D016695:Glycosyltransferases / Q000378:metabolism; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D014759:Viral Envelope Proteins / Q000378:metabolism
chemical_list: C028391:G protein, vesicular stomatitis virus; D007546:Isoquinolines; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D013449:Sulfonamides; D014759:Viral Envelope Proteins; D020126:Brefeldin A; D016695:Glycosyltransferases; D006026:Glycoside Hydrolases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide