A balance between membrane elasticity and polymerization energy sets the shape of spherical clathrin coats

Mohammed Saleem 1 Sandrine Morlot 1 Annika Hohendahl 1 John Manzi 2 Martin Lenz 3 Aurélien Roux 1

Nature Communications, [London] : Nature Pub. Group, 2015, 6, pp.6249. <10.1038/ncomms7249>

In endocytosis, scaffolding is one of the mechanisms to create membrane curvature by moulding the membrane into the spherical shape of the clathrin cage. However, the impact of membrane elastic parameters on the assembly and shape of clathrin lattices has never been experimentally evaluated. Here, we show that membrane tension opposes clathrin polymerization. We reconstitute clathrin budding in vitro with giant unilamellar vesicles (GUVs), purified adaptors and clathrin. By changing the osmotic conditions, we find that clathrin coats cause extensive budding of GUVs under low membrane tension while poly-merizing into shallow pits under moderate tension. High tension fully inhibits polymerization. Theoretically, we predict the tension values for which transitions between different clathrin coat shapes occur. We measure the changes in membrane tension during clathrin poly-merization, and use our theoretical framework to estimate the polymerization energy from these data. Our results show that membrane tension controls clathrin-mediated budding by varying the membrane budding energy.

  • 1. Department of Biochemistry
  • 2. PCC - Physico-Chimie-Curie
  • 3. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques