title: Shiga toxin stimulates clathrin-independent endocytosis of the VAMP2, VAMP3 and VAMP8 SNARE proteins.
abstract: Endocytosis is an essential cellular process that is often hijacked by pathogens and pathogenic products. Endocytic processes can be classified into two broad categories, those that are dependent on clathrin and those that are not. The SNARE proteins VAMP2, VAMP3 and VAMP8 are internalized in a clathrin-dependent manner. However, the full scope of their endocytic behavior has not yet been elucidated. Here, we found that VAMP2, VAMP3 and VAMP8 are localized on plasma membrane invaginations and very early uptake structures that are induced by the bacterial Shiga toxin, which enters cells by clathrin-independent endocytosis. We show that toxin trafficking into cells and cell intoxication rely on these SNARE proteins. Of note, the cellular uptake of VAMP3 is increased in the presence of Shiga toxin, even when clathrin-dependent endocytosis is blocked. We therefore conclude that VAMP2, VAMP3 and VAMP8 are removed from the plasma membrane by non-clathrin-mediated pathways, in addition to by clathrin-dependent uptake. Moreover, our study identifies these SNARE proteins as the first transmembrane trafficking factors that functionally associate at the plasma membrane with the toxin-driven clathrin-independent invaginations during the uptake process.
authors.affiliation: Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris 75248, Cedex 05, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France.
authors.forename: Henri-François
authors.initials: HF
authors.lastname: Renard
authors.affiliation: Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris 75248, Cedex 05, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France.
authors.forename: Maria Daniela
authors.initials: MD
authors.lastname: Garcia-Castillo
authors.affiliation: Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris 75248, Cedex 05, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Chambon
authors.affiliation: CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France Institut Curie - Centre de Recherche, Membrane Dynamics and Mechanics of Intracellular Signaling Group, 26 rue d'Ulm, Paris 75248, Cedex 05, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lamaze
authors.affiliation: Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris 75248, Cedex 05, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France ludger.johannes@curie.fr.
authors.forename: Ludger
authors.initials: L
authors.lastname: Johannes
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D066246:ErbB Receptors / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D011485:Protein Binding / Q000235:genetics; D021381:Protein Transport / Q000502:physiology*; D050683:R-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D022622:Shiga Toxin 1 / Q000494:pharmacology*; D022603:Shiga Toxins / Q000378:metabolism / Q000494:pharmacology*; D014168:Transferrin / Q000378:metabolism; D050988:Vesicle-Associated Membrane Protein 2 / Q000235:genetics / Q000378:metabolism*; D051040:Vesicle-Associated Membrane Protein 3 / Q000235:genetics / Q000378:metabolism*
chemical_list: D002966:Clathrin; D050683:R-SNARE Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D022622:Shiga Toxin 1; D022603:Shiga Toxins; D014168:Transferrin; C494807:VAMP2 protein, human; C494946:VAMP3 protein, human; C112938:VAMP8 protein, human; D050988:Vesicle-Associated Membrane Protein 2; D051040:Vesicle-Associated Membrane Protein 3; C077239:stxB toxin; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Clathrin-independent endocytosis; SNARE; Shiga toxin; VAMP2; VAMP3; VAMP8