title: Tip20p prohibits back-fusion of COPII vesicles with the endoplasmic reticulum.
abstract: Directionality in intracellular trafficking is essential to ensure the correct localization of proteins along the secretory pathway. Here, we found evidence for an active mechanism that prohibited back-fusion of de novo-generated vesicles with their donor compartment. Tip20p is a peripheral membrane protein implicated in consumption of COPI vesicles at the endoplasmic reticulum. However, a specific mutant of TIP20 did not interfere with COPII vesicle generation but allowed these vesicles to fuse back to the endoplasmic reticulum, a process that does not occur normally in the cell.
authors.affiliation: Friedrich Miescher Laboratorium der Max Planck Gesellschaft, Spemannstrasse 39, D-72076 Tübingen, Germany.
authors.forename: Faustin
authors.initials: F
authors.lastname: Kamena
authors.forename: Anne
authors.initials: A
authors.lastname: Spang
mesh_terms: D022181:COP-Coated Vesicles / Q000502:physiology* / Q000648:ultrastructure; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D006023:Glycoproteins / Q000235:genetics / Q000502:physiology*; D006056:Golgi Apparatus / Q000378:metabolism; D007425:Intracellular Membranes / Q000502:physiology / Q000648:ultrastructure; D000072235:Mating Factor; D008561:Membrane Fusion; D009154:Mutation; D010455:Peptides / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D033921:Vesicular Transport Proteins; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C489479:TIP20 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D000072235:Mating Factor; C042059:glucosidase I; D000520:alpha-Glucosidases