Archive ouverte HAL – Actin dynamics drive cell-like membrane deformation

Camille Simon 1 Rémy KustersValentina Caorsi 2 Antoine AllardMajdouline Abou-Ghali 3 John Manzi 3 Aurelie Di Cicco 3 Daniel Lévy 4 Martin Lenz 5 Jean-Francois Joanny 3 Clément Campillo 6 Julie Plastino 3 Pierre Sens 3 Cécile Sykes 7

Camille Simon, Rémy Kusters, Valentina Caorsi, Antoine Allard, Majdouline Abou-Ghali, et al.. Actin dynamics drive cell-like membrane deformation. Nature Physics, Nature Publishing Group, 2019, 15 (6), pp.602-609. ⟨10.1038/s41567-019-0464-1⟩. ⟨hal-02148264⟩

Cell membrane deformations are crucial for proper cell function. Specialized protein assemblies initiate inward or outward membrane deformations that the cell uses respectively to uptake external substances or probe the environment. The assembly and dynamics of the actin cytoskeleton are involved in this process, although their detailed role remains controversial. We show here that a dynamic, branched actin network is sufficient to initiate both inward and outward membrane deformation. The polymerization of a dense actin network at the membrane of liposomes produces inward membrane bending at low tension , while outward deformations are robustly generated regardless of tension. Our results shed light on the mechanism cells use to internalize material , both in mammalian cells, where actin polymerization forces are required when membrane tension is increased, and in yeast, where those forces are necessary to overcome the opposing turgor pressure. By combining experimental observations with physical modelling, we propose a mechanism that explains how membrane tension and the architecture of the actin network regulate cell-like membrane deformations.

  • 1. LPS - Laboratoire de Psychologie Sociale
  • 2. INSP - Institut des Nanosciences de Paris
  • 3. PCC - Physico-Chimie-Curie
  • 4. Chercheur indépendant
  • 5. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 6. LAMBE - UMR 8587 - Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement
  • 7. UPMC - Université Pierre et Marie Curie - Paris 6