title: Elastic membrane heterogeneity of living cells revealed by stiff nanoscale membrane domains.
abstract: Many approaches have been developed to characterize the heterogeneity of membranes in living cells. In this study, the elastic properties of specific membrane domains in living cells are characterized by atomic force microscopy. Our data reveal the existence of heterogeneous nanometric scale domains with specific biophysical properties. We focused on glycosylphosphatidylinositol (GPI)-anchored proteins, which play an important role in membrane trafficking and cell signaling under both physiological and pathological conditions and which are known to partition preferentially into cholesterol-rich microdomains. We demonstrate that these GPI-anchored proteins reside within domains that are stiffer than the surrounding membrane. In contrast, membrane domains containing the transferrin receptor, which does not associate with cholesterol-rich regions, manifest no such feature. The heightened stiffness of GPI domains is consistent with existing data relating to the specific condensation of lipids and the slow diffusion rates of lipids and proteins therein. Our quantitative data may forge the way to unveiling the links that exist between membrane stiffness, molecular diffusion, and signaling activation.
authors.affiliation: Cellular Neurobiology Laboratory, Brain and Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
authors.forename: Charles
authors.initials: C
authors.lastname: Roduit
authors.forename: F Gisou
authors.initials: FG
authors.lastname: van der Goot
authors.forename: Paolo
authors.initials: P
authors.lastname: De Los Rios
authors.forename: Alexandre
authors.initials: A
authors.lastname: Yersin
authors.forename: Pascal
authors.initials: P
authors.lastname: Steiner
authors.forename: Giovanni
authors.initials: G
authors.lastname: Dietler
authors.forename: Stefan
authors.initials: S
authors.lastname: Catsicas
authors.forename: Frank
authors.initials: F
authors.lastname: Lafont
authors.forename: Sandor
authors.initials: S
authors.lastname: Kasas
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D002478:Cells, Cultured; D003198:Computer Simulation; D004548:Elasticity; D006624:Hippocampus / Q000502:physiology; D021962:Membrane Microdomains / Q000502:physiology*; D008959:Models, Neurological; D049329:Nanostructures; D009474:Neurons / Q000502:physiology*; D051381:Rats; D013314:Stress, Mechanical