title: Dynamin-dependent transferrin receptor recycling by endosome-derived clathrin-coated vesicles.
abstract: Previously we described clathrin-coated buds on tubular early endosomes that are distinct from those at the plasma membrane and the trans-Golgi network. Here we show that these clathrin-coated buds, like plasma membrane clathrin-coated pits, contain endogenous dynamin-2. To study the itinerary that is served by endosome-derived clathrin-coated vesicles, we used cells that overexpressed a temperature-sensitive mutant of dynamin-1 (dynamin-1(G273D)) or, as a control, dynamin-1 wild type. In dynamin-1(G273D)-expressing cells, 29-36% of endocytosed transferrin failed to recycle at the nonpermissive temperature and remained associated with tubular recycling endosomes. Sorting of endocytosed transferrin from fluid-phase endocytosed markers in early endosome antigen 1-labeled sorting endosomes was not inhibited. Dynamin-1(G273D) associated with accumulated clathrin-coated buds on extended tubular recycling endosomes. Brefeldin A interfered with the assembly of clathrin coats on endosomes and reduced the extent of transferrin recycling in control cells but did not further affect recycling by dynamin-1(G273D)-expressing cells. Together, these data indicate that the pathway from recycling endosomes to the plasma membrane is mediated, at least in part, by endosome-derived clathrin-coated vesicles in a dynamin-dependent manner.
authors.affiliation: Department of Cell Biology, University Medical Center and Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: van Dam
authors.forename: Willem
authors.initials: W
authors.lastname: Stoorvogel
mesh_terms: D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D022163:Clathrin-Coated Vesicles / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D034284:Dynamin I; D034281:Dynamins; D004705:Endocytosis / Q000502:physiology; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D020558:GTP Phosphohydrolases / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D009154:Mutation; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D011990:Receptors, Transferrin / Q000378:metabolism*; D014168:Transferrin / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D011500:Protein Synthesis Inhibitors; D011990:Receptors, Transferrin; D014168:Transferrin; D020126:Brefeldin A; D034284:Dynamin I; D020558:GTP Phosphohydrolases; D034281:Dynamins