title: The comprehensive native interactome of a fully functional tagged prion protein.
abstract: The enumeration of the interaction partners of the cellular prion protein, PrP(C), may help clarifying its elusive molecular function. Here we added a carboxy proximal myc epitope tag to PrP(C). When expressed in transgenic mice, PrP(myc) carried a GPI anchor, was targeted to lipid rafts, and was glycosylated similarly to PrP(C). PrP(myc) antagonized the toxicity of truncated PrP, restored prion infectibility of PrP(C)-deficient mice, and was physically incorporated into PrP(Sc) aggregates, indicating that it possessed all functional characteristics of genuine PrP(C). We then immunopurified myc epitope-containing protein complexes from PrP(myc) transgenic mouse brains. Gentle differential elution with epitope-mimetic decapeptides, or a scrambled version thereof, yielded 96 specifically released proteins. Quantitative mass spectrometry with isotope-coded tags identified seven proteins which co-eluted equimolarly with PrP(C) and may represent component of a multiprotein complex. Selected PrP(C) interactors were validated using independent methods. Several of these proteins appear to exert functions in axomyelinic maintenance.
authors.affiliation: Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Rutishauser
authors.forename: Kirsten D
authors.initials: KD
authors.lastname: Mertz
authors.forename: Rita
authors.initials: R
authors.lastname: Moos
authors.forename: Erich
authors.initials: E
authors.lastname: Brunner
authors.forename: Thomas
authors.initials: T
authors.lastname: Rülicke
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Calella
authors.forename: Adriano
authors.initials: A
authors.lastname: Aguzzi
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D007553:Isotope Labeling; D013058:Mass Spectrometry; D051379:Mice; D008822:Mice, Transgenic; D009420:Nervous System / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D018620:PrPSc Proteins / Q000302:isolation & purification / Q000378:metabolism; D011328:Prions / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism*; D016019:Survival Analysis
chemical_list: D003902:Detergents; D018620:PrPSc Proteins; D011328:Prions; D011993:Recombinant Fusion Proteins