title: The N Terminus of the Prion Protein Mediates Functional Interactions with the Neuronal Cell Adhesion Molecule (NCAM) Fibronectin Domain.
abstract: The cellular form of the prion protein (PrPC) is a highly conserved glycoprotein mostly expressed in the central and peripheral nervous systems by different cell types in mammals. A misfolded, pathogenic isoform, denoted as prion, is related to a class of neurodegenerative diseases known as transmissible spongiform encephalopathy. PrPCfunction has not been unequivocally clarified, and it is rather defined as a pleiotropic protein likely acting as a dynamic cell surface scaffolding protein for the assembly of different signaling modules. Among the variety of PrPCprotein interactors, the neuronal cell adhesion molecule (NCAM) has been studied in vivo, but the structural basis of this functional interaction is still a matter of debate. Here we focused on the structural determinants responsible for human PrPC(HuPrP) and NCAM interaction using stimulated emission depletion (STED) nanoscopy, SPR, and NMR spectroscopy approaches. PrPCco-localizes with NCAM in mouse hippocampal neurons, and this interaction is mainly mediated by the intrinsically disordered PrPCN-terminal tail, which binds with high affinity to the NCAM fibronectin type-3 domain. NMR structural investigations revealed surface-interacting epitopes governing the interaction between HuPrP N terminus and the second module of the NCAM fibronectin type-3 domain. Our data provided molecular details about the interaction between HuPrP and the NCAM fibronectin domain, and revealed a new role of PrPCN terminus as a dynamic and functional element responsible for protein-protein interaction.
authors.affiliation: From the Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
authors.forename: Urška
authors.initials: U
authors.lastname: Slapšak
authors.affiliation: the Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, Trieste I-34136, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Salzano
authors.affiliation: the Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, Trieste I-34136, Italy.
authors.forename: Ladan
authors.initials: L
authors.lastname: Amin
authors.affiliation: the Structural Biology Research Center, Vrije Universiteit Brussel, VIB, Pleinlaan 2, 1050, Brussels, Belgium, the National Institute of Oceanography and Fisheries (NIOF), 11516 Cairo, Egypt, and the Van Andel Research Institute, Grand Rapids, Michigan 49503.
authors.forename: Romany N N
authors.initials: RN
authors.lastname: Abskharon
authors.affiliation: From the Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia, the EN-FIST Centre of Excellence, Dunajska 156, SI-1000 Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Ilc
authors.affiliation: From the Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
authors.forename: Blaž
authors.initials: B
authors.lastname: Zupančič
authors.affiliation: the Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102A, Zagreb HR-10000, Croatia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Biljan
authors.affiliation: From the Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia, the EN-FIST Centre of Excellence, Dunajska 156, SI-1000 Ljubljana, Slovenia, the Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia, janez.plavec@ki.si.
authors.forename: Janez
authors.initials: J
authors.lastname: Plavec
authors.affiliation: the Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, Trieste I-34136, Italy, the Structural Biology Group, European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000-Grenoble, France.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Giachin
authors.affiliation: the Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, Trieste I-34136, Italy, legname@sissa.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Legname
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D051379:Mice; D019006:Neural Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D018621:PrPC Proteins / Q000737:chemistry / Q000378:metabolism*; D000072417:Protein Domains
chemical_list: D019006:Neural Cell Adhesion Molecules; D018621:PrPC Proteins
keywords: NCAM; NMR spectroscopy; STED; cell adhesion; fibronectin; fibronectin type-3 domain; nuclear magnetic resonance (NMR); prion; prion protein; protein-protein interaction; stimulated emission depletion microscopy