title: Receptor and protein kinase C-mediated regulation of ARF binding to the Golgi complex.
abstract: The formation of constitutive transport vesicles involves the association of non-clathrin coat proteins to transport organelles. Here we report that IgE receptors and protein kinase C (PKC) regulate the GTP-dependent binding of the two coat proteins ADP-ribosylation factor (ARF) and beta-COP to Golgi membranes in rat basophilic leukaemia cells. Activation of IgE receptors and PKC prevented the ARF and beta-COP dissociation from Golgi membranes that occurs in permeabilized cells in the absence of GTP and potentiated the association-promoting effects of GTP and the G protein activator fluoroaluminate. In contrast, PKC downregulation and PKC inhibition abolished the activity of GTP and fluoroaluminae in promoting ARF binding to the Golgi complex. Studies of ARF binding to isolated Golgi membranes gave similar results. These findings suggest that coat assembly on Golgi membranes, and thus possibly constitutive secretory traffic, is modulated by membrane receptors and second messengers.
authors.affiliation: Unit of Physiopathology of Secretion, Istituto di Ricerche Farmacologiche Mario Negri, Santa Maria Imbaro, Chieti, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: De Matteis
authors.forename: G
authors.initials: G
authors.lastname: Santini
authors.forename: R A
authors.initials: RA
authors.lastname: Kahn
authors.forename: G
authors.initials: G
authors.lastname: Di Tullio
authors.forename: A
authors.initials: A
authors.lastname: Luini
mesh_terms: D020727:ADP-Ribosylation Factors; D000535:Aluminum / Q000494:pharmacology; D000818:Animals; D020126:Brefeldin A; D002463:Cell Membrane Permeability; D020756:Coatomer Protein; D003517:Cyclopentanes / Q000494:pharmacology; D004789:Enzyme Activation; D005461:Fluorine / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009281:Naphthalenes; D010703:Phorbol Esters / Q000494:pharmacology; D011083:Polycyclic Compounds / Q000494:pharmacology; D011485:Protein Binding; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017455:Receptors, IgE / Q000378:metabolism*; D015290:Second Messenger Systems; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D020756:Coatomer Protein; D003517:Cyclopentanes; D006025:Glycosaminoglycans; D008869:Microtubule-Associated Proteins; D009281:Naphthalenes; D010703:Phorbol Esters; D011083:Polycyclic Compounds; D017455:Receptors, IgE; D020126:Brefeldin A; C053629:fluoroaluminum; C008876:phorbol-12,13-didecanoate; D005461:Fluorine; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D000535:Aluminum; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors; C058819:calphostin C; D013755:Tetradecanoylphorbol Acetate