title: Cell-sized liposome doublets reveal active tension build-up driven by acto-myosin dynamics.
abstract: Cells modulate their shape to fulfill specific functions, mediated by the cell cortex, a thin actin shell bound to the plasma membrane. Myosin motor activity, together with actin dynamics, contributes to cortical tension. Here, we examine the individual contributions of actin polymerization and myosin activity to tension increase with a non-invasive method. Cell-sized liposome doublets are covered with either a stabilized actin cortex of preformed actin filaments, or a dynamic branched actin network polymerizing at the membrane. The addition of myosin II minifilaments in both cases triggers a change in doublet shape that is unambiguously related to a tension increase. Preformed actin filaments allow us to evaluate the effect of myosin alone while, with dynamic actin cortices, we examine the synergy of actin polymerization and myosin motors in driving shape changes. Our assay paves the way for a quantification of tension changes triggered by various actin-associated proteins in a cell-sized system.
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France.
authors.forename: V
authors.initials: V
authors.lastname: Caorsi
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France and Univ Paris Diderot, Sorbonne Paris Cité, Paris, F-75205, France and Department of Molecular Biophysics and Biochemistry, Nanobiology Institute, Yale University, New Haven, CT, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lemière
authors.affiliation: Université Evry Val d'Essonne, LAMBE, Boulevard F Mitterrand, Evry 91025, France.
authors.forename: C
authors.initials: C
authors.lastname: Campillo
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France and Univ Paris Diderot, Sorbonne Paris Cité, Paris, F-75205, France.
authors.forename: M
authors.initials: M
authors.lastname: Bussonnier
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Manzi
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France and Institute of Cell Biology, Center for Molecular Biology of Inflammation, Cells-in-Motion Cluster of Excellence, Münster University, Von-Esmarch-Strasse 56, D-48149 Münster, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Betz
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Plastino
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France.
authors.forename: K
authors.initials: K
authors.lastname: Carvalho
authors.affiliation: Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS, UMR168, 75005, Paris, France and Sorbonne Universités, UPMC Univ Paris 06, 75005, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Sykes
mesh_terms: D008841:Actin Cytoskeleton; D000199:Actins / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D024462:Myosin Type II; D009218:Myosins / Q000737:chemistry*
chemical_list: D000199:Actins; D008081:Liposomes; D024462:Myosin Type II; D009218:Myosins