title: Nanoclusters of the resting T cell antigen receptor (TCR) localize to non-raft domains.
abstract: In the last decade an increasing number of plasma membrane (PM) proteins have been shown to be non-randomly distributed but instead forming submicron-sized oligomers called nanoclusters. Nanoclusters exist independently of the ligand-bound state of the receptors and their existence implies a high degree of lateral organisation of the PM and its proteins. The mechanisms that drive receptor nanoclustering are largely unknown. One well-defined example of a transmembrane receptor that forms nanoclusters is the T cell antigen receptor (TCR), a multisubunit protein complex whose nanoclustering influences its activity. Membrane lipids, namely cholesterol and sphingomyelin, have been shown to contribute to TCR nanoclustering. However, the identity of the membrane microdomain in which the TCR resides remains controversial. Using a GFP-labeled TCR we show here that the resting TCR localized in the disordered domain of giant PM vesicles (GPMVs) and PM spheres (PMSs) and that single and nanoclustered TCRs are found in the high-density fractions in sucrose gradients. Both findings are indicative of non-raft localization. We discuss possible mechanisms of TCR nanoclustering in T cells. This article is part of a Special Issue entitled: Nanoscale membrane organisation and signalling.
authors.affiliation: Department of Molecular Immunology, Faculty of Biology, BIOSS Center for Biological Signalling Studies, Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), Freiburg, Germany; Centre for Chronic Immunodeficiency CCI, Albert-Ludwigs-University Freiburg, Germany; Max Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Beck-García
authors.affiliation: Department of Molecular Immunology, Faculty of Biology, BIOSS Center for Biological Signalling Studies, Freiburg, Germany; Centre for Chronic Immunodeficiency CCI, Albert-Ludwigs-University Freiburg, Germany; Max Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS-MCB), Freiburg, Germany.
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Beck-García
authors.affiliation: Department of Molecular Immunology, Faculty of Biology, BIOSS Center for Biological Signalling Studies, Freiburg, Germany; Max Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany.
authors.forename: Sheila
authors.initials: S
authors.lastname: Bohler
authors.affiliation: Department of Molecular Immunology, Faculty of Biology, BIOSS Center for Biological Signalling Studies, Freiburg, Germany; Centre for Chronic Immunodeficiency CCI, Albert-Ludwigs-University Freiburg, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Zorzin
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
authors.forename: Erdinc
authors.initials: E
authors.lastname: Sezgin
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, USA.
authors.forename: Ilya
authors.initials: I
authors.lastname: Levental
authors.affiliation: Centro de Biología Molecular Severo Ochoa, CSIC-Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Balbino
authors.initials: B
authors.lastname: Alarcón
authors.affiliation: Department of Molecular Immunology, Faculty of Biology, BIOSS Center for Biological Signalling Studies, Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), Freiburg, Germany; Centre for Chronic Immunodeficiency CCI, Albert-Ludwigs-University Freiburg, Germany; Max Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany. Electronic address: wolfgang.schamel@biologie.uni-freiburg.de.
authors.forename: Wolfgang W A
authors.initials: WW
authors.lastname: Schamel
mesh_terms: D000818:Animals; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008055:Lipids / Q000737:chemistry; D021962:Membrane Microdomains / Q000378:metabolism*; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D051381:Rats; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D053835:Unilamellar Liposomes / Q000378:metabolism
chemical_list: D008055:Lipids; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D053835:Unilamellar Liposomes; D049452:Green Fluorescent Proteins
keywords: Cholesterol; Lipid; Membrane; Nanoclustering; TCR