title: Mapping the energy and diffusion landscapes of membrane proteins at the cell surface using high-density single-molecule imaging and Bayesian inference: application to the multiscale dynamics of glycine receptors in the neuronal membrane.
abstract: Protein mobility is conventionally analyzed in terms of an effective diffusion. Yet, this description often fails to properly distinguish and evaluate the physical parameters (such as the membrane friction) and the biochemical interactions governing the motion. Here, we present a method combining high-density single-molecule imaging and statistical inference to separately map the diffusion and energy landscapes of membrane proteins across the cell surface at ~100 nm resolution (with acquisition of a few minutes). Upon applying these analytical tools to glycine neurotransmitter receptors at inhibitory synapses, we find that gephyrin scaffolds act as shallow energy traps (~3 kBT) for glycine neurotransmitter receptors, with a depth modulated by the biochemical properties of the receptor-gephyrin interaction loop. In turn, the inferred maps can be used to simulate the dynamics of proteins in the membrane, from the level of individual receptors to that of the population, and thereby, to model the stochastic fluctuations of physiological parameters (such as the number of receptors at synapses). Overall, our approach provides a powerful and comprehensive framework with which to analyze biochemical interactions in living cells and to decipher the multiscale dynamics of biomolecules in complex cellular environments.
authors.affiliation: Physics of Biological Systems, Pasteur Institute, Paris, France; Centre National de la Recherche Scientifique UMR 3525, Paris, France. Electronic address: jbmasson@pasteur.fr.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Masson
authors.affiliation: Laboratoire Kastler Brossel, Centre National de la Recherche Scientifique UMR 8552, Ecole Normale Superieure, Paris, France; Centre de Recherche Universit Laval Robert-Giffard, Quebec, Canada.
authors.forename: Patrice
authors.initials: P
authors.lastname: Dionne
authors.affiliation: Biologie Cellulaire de la Synapse, Institut National de la Sante et de la Recherche Medicale U1024, Institut de Biologie de l'Ecole Normale Superieure, Paris, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Salvatico
authors.affiliation: Biologie Cellulaire de la Synapse, Institut National de la Sante et de la Recherche Medicale U1024, Institut de Biologie de l'Ecole Normale Superieure, Paris, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Renner
authors.affiliation: Biologie Cellulaire de la Synapse, Institut National de la Sante et de la Recherche Medicale U1024, Institut de Biologie de l'Ecole Normale Superieure, Paris, France.
authors.forename: Christian G
authors.initials: CG
authors.lastname: Specht
authors.affiliation: Biologie Cellulaire de la Synapse, Institut National de la Sante et de la Recherche Medicale U1024, Institut de Biologie de l'Ecole Normale Superieure, Paris, France. Electronic address: triller@biologie.ens.fr.
authors.forename: Antoine
authors.initials: A
authors.lastname: Triller
authors.affiliation: Laboratoire Kastler Brossel, Centre National de la Recherche Scientifique UMR 8552, Ecole Normale Superieure, Paris, France; Laboratoire Physico-Chimie, Institut Curie, Centre National de la Recherche Scientifique UMR 168, Universit Pierre et Marie Curie-Paris 6, Paris, France. Electronic address: maxime.dahan@curie.fr.
authors.forename: Maxime
authors.initials: M
authors.lastname: Dahan
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism; D004058:Diffusion; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D061848:Optical Imaging; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D018009:Receptors, Glycine / Q000737:chemistry / Q000378:metabolism*; D013269:Stochastic Processes; D013570:Synaptic Membranes / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D018009:Receptors, Glycine; C073441:gephyrin