title: Endophilin-A2 functions in membrane scission in clathrin-independent endocytosis.
abstract: During endocytosis, energy is invested to narrow the necks of cargo-containing plasma membrane invaginations to radii at which the opposing segments spontaneously coalesce, thereby leading to the detachment by scission of endocytic uptake carriers. In the clathrin pathway, dynamin uses mechanical energy from GTP hydrolysis to this effect, assisted by the BIN/amphiphysin/Rvs (BAR) domain-containing protein endophilin. Clathrin-independent endocytic events are often less reliant on dynamin, and whether in these cases BAR domain proteins such as endophilin contribute to scission has remained unexplored. Here we show, in human and other mammalian cell lines, that endophilin-A2 (endoA2) specifically and functionally associates with very early uptake structures that are induced by the bacterial Shiga and cholera toxins, which are both clathrin-independent endocytic cargoes. In controlled in vitro systems, endoA2 reshapes membranes before scission. Furthermore, we demonstrate that endoA2, dynamin and actin contribute in parallel to the scission of Shiga-toxin-induced tubules. Our results establish a novel function of endoA2 in clathrin-independent endocytosis. They document that distinct scission factors operate in an additive manner, and predict that specificity within a given uptake process arises from defined combinations of universal modules. Our findings highlight a previously unnoticed link between membrane scaffolding by endoA2 and pulling-force-driven dynamic scission.
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Henri-François
authors.initials: HF
authors.lastname: Renard
authors.affiliation: 1] Institut Curie - Centre de Recherche, Membrane and Cell Functions group, CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] The University of Chicago, Department of Chemistry, 5735 S Ellis Ave, Chicago, Ilinois 60637, USA.
authors.forename: Mijo
authors.initials: M
authors.lastname: Simunovic
authors.affiliation: 1] Institut Curie - Centre de Recherche, Biomimetism of Cell Movement group, CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Lemière
authors.affiliation: Institute of Structural and Molecular Biology, University College London &Birkbeck College, London WC1E 6BT, UK.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Boucrot
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Maria Daniela
authors.initials: MD
authors.lastname: Garcia-Castillo
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Senthil
authors.initials: S
authors.lastname: Arumugam
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Chambon
authors.affiliation: 1] CNRS UMR3666, 75005 Paris, France [2] U1143 INSERM, 75005 Paris, France [3] Institut Curie - Centre de Recherche, Membrane Dynamics and Mechanics of Intracellular Signaling group, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lamaze
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Wunder
authors.affiliation: Vanderbilt School of Medicine, Department of Molecular Physiology and Biophysics, 718 Light Hall, Nashville, Tennessee 37232, USA.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Kenworthy
authors.affiliation: CNRS, UMR7592, Institut Jacques Monod, Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, 75205 Paris Cedex 13, France.
authors.forename: Anne A
authors.initials: AA
authors.lastname: Schmidt
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Harvey T
authors.initials: HT
authors.lastname: McMahon
authors.affiliation: Institut Curie - Centre de Recherche, Biomimetism of Cell Movement group, CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Sykes
authors.affiliation: Institut Curie - Centre de Recherche, Membrane and Cell Functions group, CNRS UMR 168, Physico-Chimie Curie, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bassereau
authors.affiliation: 1] Institut Curie - Centre de Recherche, Endocytic Trafficking and Therapeutic Delivery group, 26 rue d'Ulm, 75248 Paris Cedex 05, France [2] CNRS UMR3666, 75005 Paris, France [3] U1143 INSERM, 75005 Paris, France.
authors.forename: Ludger
authors.initials: L
authors.lastname: Johannes
mesh_terms: D000199:Actins / Q000378:metabolism; D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002772:Cholera Toxin / Q000378:metabolism; D002966:Clathrin; D034281:Dynamins / Q000378:metabolism; D004705:Endocytosis; D006801:Humans; D051381:Rats; D022621:Shiga Toxin / Q000378:metabolism
chemical_list: D000199:Actins; D002966:Clathrin; D022621:Shiga Toxin; D002772:Cholera Toxin; D000217:Acyltransferases; C018764:2-acylglycerophosphate acyltransferase; D034281:Dynamins