title: Receptor dimer stabilization by hierarchical plasma membrane microcompartments regulates cytokine signaling.
abstract: The interaction dynamics of signaling complexes is emerging as a key determinant that regulates the specificity of cellular responses. We present a combined experimental and computational study that quantifies the consequences of plasma membrane microcompartmentalization for the dynamics of type I interferon receptor complexes. By using long-term dual-color quantum dot (QD) tracking, we found that the lifetime of individual ligand-induced receptor heterodimers depends on the integrity of the membrane skeleton (MSK), which also proved important for efficient downstream signaling. By pair correlation tracking and localization microscopy as well as by fast QD tracking, we identified a secondary confinement within ~300-nm-sized zones. A quantitative spatial stochastic diffusion-reaction model, entirely parameterized on the basis of experimental data, predicts that transient receptor confinement by the MSK meshwork allows for rapid reassociation of dissociated receptor dimers. Moreover, the experimentally observed apparent stabilization of receptor dimers in the plasma membrane was reproduced by simulations of a refined, hierarchical compartment model. Our simulations further revealed that the two-dimensional association rate constant is a key parameter for controlling the extent of MSK-mediated stabilization of protein complexes, thus ensuring the specificity of this effect. Together, experimental evidence and simulations support the hypothesis that passive receptor confinement by MSK-based microcompartmentalization promotes maintenance of signaling complexes in the plasma membrane.
authors.affiliation: Department of Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
authors.forename: Changjiang
authors.identifier: 0000-0002-7839-6397
authors.initials: C
authors.lastname: You
authors.affiliation: Isaac Newton Institute for Mathematical Sciences, University of Cambridge, Cambridge, U.K.
authors.forename: Tatiana T
authors.initials: TT
authors.lastname: Marquez-Lago
authors.affiliation: Department of Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
authors.forename: Christian Paolo
authors.initials: CP
authors.lastname: Richter
authors.affiliation: Department of Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Wilmes
authors.affiliation: Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.; Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Moraga
authors.affiliation: Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.; Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: K Christopher
authors.initials: KC
authors.lastname: Garcia
authors.affiliation: Isaac Newton Institute for Mathematical Sciences, University of Cambridge, Cambridge, U.K.; Okinawa Institute of Science and Technology, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan.
authors.forename: André
authors.initials: A
authors.lastname: Leier
authors.affiliation: Department of Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
authors.forename: Jacob
authors.identifier: 0000-0002-2143-2270
authors.initials: J
authors.lastname: Piehler
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology*; D016207:Cytokines / Q000378:metabolism*; D004058:Diffusion; D006801:Humans; D008856:Microscopy, Fluorescence; D055503:Protein Multimerization; D045663:Quantum Dots; D053633:Receptor, Interferon alpha-beta / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D016207:Cytokines; C507964:IFNAR1 protein, human; C508033:IFNAR2 protein, human; D053633:Receptor, Interferon alpha-beta
keywords: Cytokine receptor signaling; hop diffusion; plasma membrane organization; protein-protein interaction; single molecule tracking; spatial stochastic modeling; type I interferon receptor