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Article

  • The EMBO Journal (2006) 25, 3245 - 3256
  • doi:10.1038/sj.emboj.7601214

Published online: 6 July 2006

Dynamic molecular confinement in the plasma membrane by microdomains and the cytoskeleton meshwork

Pierre-François Lenne1,2,a, Laure Wawrezinieck1,2,3,4,5,a, Fabien Conchonaud3,4,5, Olivier Wurtz3,4,5,b, Annie Boned3,4,5, Xiao-Jun Guo3,4,5,6, Hervé Rigneault1,2, Hai-Tao He3,4,5 and Didier Marguet3,4,5

  1. Institut Fresnel, Université Paul Cézanne, Marseille, France
  2. CNRS UMR 6133, Marseille, France
  3. Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Marseille, France
  4. INSERM, UMR 631, Marseille, France
  5. CNRS, UMR 6102, Marseille, France
  6. Laboratoire de Biochimie et Physicochimie des Membranes Biologiques, Université Paul Cézanne, Marseille, France

Correspondence to:

Didier Marguet, Centre d'Immunologie de Marseille Luminy, CNRS, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 13009, France. Tel.: +33 491 269 128; Fax: +33 491 269 430; E-mail: marguet@ciml.univ-mrs.fr

aThese authors contributed equally to this work

bPresent address: Université de Rouen, INSERM U413, Mont Saint Aignan, France

Received 9 February 2006; Accepted 6 June 2006

It is by now widely recognized that cell membranes show complex patterns of lateral organization. Two mechanisms involving either a lipid-dependent (microdomain model) or cytoskeleton-based (meshwork model) process are thought to be responsible for these plasma membrane organizations. In the present study, fluorescence correlation spectroscopy measurements on various spatial scales were performed in order to directly identify and characterize these two processes in live cells with a high temporal resolution, without any loss of spatial information. Putative raft markers were found to be dynamically compartmented within tens of milliseconds into small microdomains (Empty set variant<120 nm) that are sensitive to the cholesterol and sphingomyelin levels, whereas actin-based cytoskeleton barriers are responsible for the confinement of the transferrin receptor protein. A free-like diffusion was observed when both the lipid-dependent and cytoskeleton-based organizations were disrupted, which suggests that these are two main compartmentalizing forces at work in the plasma membrane.

  • Keywords:

    • actin meshwork,
    • confined diffusion,
    • fluorescence correlation spectroscopy,
    • lipid rafts,
    • membrane microdomain