title: The molecular size of the extra-membrane domain influences the diffusion of the GPI-anchored VSG on the trypanosome plasma membrane.
abstract: A plethora of proteins undergo random and passive diffusion in biological membranes. While the contribution of the membrane-embedded domain to diffusion is well established, the potential impact of the extra-membrane protein part has been largely neglected. Here, we show that the molecular length influences the diffusion coefficient of GPI-anchored proteins: smaller proteins diffuse faster than larger ones. The distinct diffusion properties of differently sized membrane proteins are biologically relevant. The variant surface glycoprotein (VSG) of African trypanosomes, for example, is sized for an effective diffusion-driven randomization on the cell surface, a process that is essential for parasite virulence. We propose that the molecular sizes of proteins dominating the cell surfaces of other eukaryotic pathogens may also be related to diffusion-limited functions.
authors.affiliation: 1] Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany [2] Department of Electrical Engineering, Bioeelectrical Systems Lab, Columbia University, New York, New York 10027, USA.
authors.forename: Andreas J W
authors.initials: AJ
authors.lastname: Hartel
authors.affiliation: Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Glogger
authors.affiliation: Experimental Physics I, University of Bayreuth, Bayreuth, Germany.
authors.forename: Gernot
authors.initials: G
authors.lastname: Guigas
authors.affiliation: Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Nicola G
authors.initials: NG
authors.lastname: Jones
authors.affiliation: Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Susanne F
authors.initials: SF
authors.lastname: Fenz
authors.affiliation: Experimental Physics I, University of Bayreuth, Bayreuth, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Weiss
authors.affiliation: Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Engstler
mesh_terms: D058851:GPI-Linked Proteins / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000378:metabolism*
chemical_list: D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins