Tip20p prohibits back-fusion of COPII vesicles with the endoplasmic reticulum.
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.
Kamena
Faustin
F
Friedrich Miescher Laboratorium der Max Planck Gesellschaft, Spemannstrasse 39, D-72076 Tübingen, Germany.
Spang
Anne
A
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
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