title: Glycosylation and Lipids Working in Concert Direct CD2 Ectodomain Orientation and Presentation.
abstract: Proteins embedded in the plasma membrane mediate interactions with the cell environment and play decisive roles in many signaling events. For cell-cell recognition molecules, it is highly likely that their structures and behavior have been optimized in ways that overcome the limitations of membrane tethering. In particular, the ligand binding regions of these proteins likely need to be maximally exposed. Here we show by means of atomistic simulations of membrane-bound CD2, a small cell adhesion receptor expressed by human T-cells and natural killer cells, that the presentation of its ectodomain is highly dependent on membrane lipids and receptor glycosylation acting in apparent unison. Detailed analysis shows that the underlying mechanism is based on electrostatic interactions complemented by steric interactions between glycans in the protein and the membrane surface. The findings are significant for understanding the factors that render membrane receptors accessible for binding and signaling.
authors.affiliation: Department of Physics, Tampere University of Technology , Korkeakoulunkatu 10, P.O. Box 692, FI-33101 Tampere, Finland.
authors.forename: Anirban
authors.initials: A
authors.lastname: Polley
authors.affiliation: Department of Physics, Tampere University of Technology , Korkeakoulunkatu 10, P.O. Box 692, FI-33101 Tampere, Finland.|Department of Physics and Energy, University of Limerick , Limerick V94 T9PX, Ireland.
authors.forename: Adam
authors.identifier: http://orcid.org/0000-0003-1599-1022
authors.initials: A
authors.lastname: Orłowski
authors.affiliation: Department of Physics, Tampere University of Technology , Korkeakoulunkatu 10, P.O. Box 692, FI-33101 Tampere, Finland.
authors.forename: Reinis
authors.initials: R
authors.lastname: Danne
authors.affiliation: Institute of Macromolecular Compounds, Russian Academy of Sciences , Bolshoi Prospect V.O. 31, St. Petersburg, 199004 Russia.|Faculty of Physics, St. Petersburg State University , Ulyanovskaya Strasse 3, Petrodvorets, St. Petersburg, 198504 Russia.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Gurtovenko
authors.affiliation: Science and Technology Facilities Council , Rutherford Appleton Laboratory, Central Laser Facility, Research Complex at Harwell, Harwell-Oxford Campus, OX11 0FA Didcot, United Kingdom.
authors.forename: Jorge
authors.identifier: http://orcid.org/0000-0002-1396-3338
authors.initials: J
authors.lastname: Bernardino de la Serna
authors.affiliation: MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford , Headley Way, OX3 9DS Oxford, United Kingdom.
authors.forename: Christian
authors.initials: C
authors.lastname: Eggeling
authors.affiliation: MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford , Headley Way, OX3 9DS Oxford, United Kingdom.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Davis
authors.affiliation: Department of Physics, Tampere University of Technology , Korkeakoulunkatu 10, P.O. Box 692, FI-33101 Tampere, Finland.|Department of Physics, University of Helsinki , P.O. Box 64, FI-00014 Helsinki, Finland.
authors.forename: Tomasz
authors.identifier: http://orcid.org/0000-0001-6765-7013
authors.initials: T
authors.lastname: Róg
authors.affiliation: Department of Physics, Tampere University of Technology , Korkeakoulunkatu 10, P.O. Box 692, FI-33101 Tampere, Finland.|Department of Physics, University of Helsinki , P.O. Box 64, FI-00014 Helsinki, Finland.|Department of Physics and Chemistry, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark , Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Ilpo
authors.identifier: http://orcid.org/0000-0001-7408-3214
authors.initials: I
authors.lastname: Vattulainen