title: The ADP-ribosylation factor GTPase-activating protein Glo3p is involved in ER retrieval.
abstract: Retrograde transport of proteins from the Golgi to the endoplasmic reticulum (ER) has been the subject of some interest in the recent past. Here a new thermosensitive yeast mutant defective in retrieval of dilysine-tagged proteins from the Golgi back to the endoplasmic reticulum was characterized. The ret4-1 mutant also exhibited a selective defect in forward ER-to-Golgi transport of some secreted proteins at the non-permissive temperature. The corresponding RET4 gene was found to encode Glo3p, a GTPase-activating protein (GAP) specific for ADP-ribosylation factor (ARF). In vitro, the Glo3 thermosensitive mutant showed a reduced ARF1-GAP activity. The Glo3 protein belongs to a family of zinc finger proteins that may include additional ARF-GAPs. Gene deletion experiments of other family members showed that only GLO3 deletion resulted in impaired retrieval of dilysine-tagged proteins back to the ER. These results demonstrate that Glo3p is the main ARF-GAP specifically involved in ER retrieval.
authors.affiliation: Institut de Biologie et de Chimie des Protéines, IBCP/UPR412, CNRS, Lyon, France.
authors.forename: D
authors.initials: D
authors.lastname: Dogic
authors.forename: B
authors.initials: B
authors.lastname: de Chassey
authors.forename: E
authors.initials: E
authors.lastname: Pick
authors.forename: D
authors.initials: D
authors.lastname: Cassel
authors.forename: Y
authors.initials: Y
authors.lastname: Lefkir
authors.forename: S
authors.initials: S
authors.lastname: Hennecke
authors.forename: P
authors.initials: P
authors.lastname: Cosson
authors.forename: F
authors.initials: F
authors.lastname: Letourneur
mesh_terms: D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; D001692:Biological Transport; D001693:Biological Transport, Active; D020756:Coatomer Protein; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D020690:GTPase-Activating Proteins; D007424:Intracellular Fluid / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D016296:Mutagenesis; D011506:Proteins / Q000378:metabolism*; D015003:Yeasts
chemical_list: D020756:Coatomer Protein; D020690:GTPase-Activating Proteins; D008565:Membrane Proteins; D011506:Proteins; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; D008239:Lysine