title: Intra- and interspecies interactions between prion proteins and effects of mutations and polymorphisms.
abstract: Recently, crystallization of the prion protein in a dimeric form was reported. Here we show that native soluble homogeneous FLAG-tagged prion proteins from hamster, man and cattle expressed in the baculovirus system are predominantly dimeric. The PrP/PrP interaction was confirmed in Semliki Forest virus-RNA transfected BHK cells co-expressing FLAG- and oligohistidine-tagged human PrP. The yeast two-hybrid system identified the octarepeat region and the C-terminal structured domain (aa90-aa230) of PrP as PrP/PrP interaction domains. Additional octarepeats identified in patients suffering from fCJD reduced (wtPrP versus PrP + 9OR) and completely abolished (PrP + 9OR versus PrP + 9OR) the PrP/PrP interaction in the yeast two-hybrid system. In contrast, the Met/Val polymorphism (aa129), the GSS mutation Pro102Leu and the FFI mutation Asp178Asn did not affect PrP/PrP interactions. Proof of interactions between human or sheep and bovine PrP, and sheep and human PrP, as well as lack of interactions between human or bovine PrP and hamster PrP suggest that interspecies PrP interaction studies in the yeast two-hybrid system may serve as a rapid pre-assay to investigate species barriers in prion diseases.
authors.affiliation: Laboratorium für Molekulare Biologie-Genzentrum, Institut für Biochemie der Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, D-81377 München, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hundt
authors.forename: Sabine
authors.initials: S
authors.lastname: Gauczynski
authors.forename: Christoph
authors.initials: C
authors.lastname: Leucht
authors.forename: M Louise
authors.initials: ML
authors.lastname: Riley
authors.forename: Stefan
authors.initials: S
authors.lastname: Weiss
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D006224:Cricetinae; D019281:Dimerization; D006801:Humans; D009154:Mutation / Q000502:physiology*; D020641:Polymorphism, Single Nucleotide / Q000502:physiology*; D018621:PrPC Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D012672:Semliki forest virus / Q000235:genetics; D012756:Sheep; D013045:Species Specificity; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: D018621:PrPC Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins