title: Assessment of the PrPc Amino-Terminal Domain in Prion Species Barriers.
abstract: Chronic wasting disease (CWD) in cervids and bovine spongiform encephalopathy (BSE) in cattle are prion diseases that are caused by the same protein-misfolding mechanism, but they appear to pose different risks to humans. We are interested in understanding the differences between the species barriers of CWD and BSE. We used real-time, quaking-induced conversion (RT-QuIC) to model the central molecular event in prion disease, the templated misfolding of the normal prion protein, PrPc, to a pathogenic, amyloid isoform, scrapie prion protein, PrPScWe examined the role of the PrPcamino-terminal domain (N-terminal domain [NTD], amino acids [aa] 23 to 90) in cross-species conversion by comparing the conversion efficiency of various prion seeds in either full-length (aa 23 to 231) or truncated (aa 90 to 231) PrPcWe demonstrate that the presence of white-tailed deer and bovine NTDs hindered seeded conversion of PrPc, but human and bank vole NTDs did the opposite. Additionally, full-length human and bank vole PrPcs were more likely to be converted to amyloid by CWD prions than were their truncated forms. A chimera with replacement of the human NTD by the bovine NTD resembled human PrPcThe requirement for an NTD, but not for the specific human sequence, suggests that the NTD interacts with other regions of the human PrPcto increase promiscuity. These data contribute to the evidence that, in addition to primary sequence, prion species barriers are controlled by interactions of the substrate NTD with the rest of the substrate PrPcmolecule.
  
  
  OBJECTIVE
  We demonstrate that the amino-terminal domain of the normal prion protein, PrPc, hinders seeded conversion of bovine and white-tailed deer PrPcs to the prion forms, but it facilitates conversion of the human and bank vole PrPcs to the prion forms. Additionally, we demonstrate that the amino-terminal domain of human and bank vole PrPcs requires interaction with the rest of the molecule to facilitate conversion by CWD prions. These data suggest that interactions of the amino-terminal domain with the rest of the PrPcmolecule play an important role in the susceptibility of humans to CWD prions.
authors.affiliation: Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Davenport
authors.affiliation: Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Davin M
authors.initials: DM
authors.lastname: Henderson
authors.affiliation: Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Candace K
authors.initials: CK
authors.lastname: Mathiason
authors.affiliation: Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA edward.hoover@colostate.edu.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Hoover
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003411:Arvicolinae; D001921:Brain / Q000378:metabolism; D002417:Cattle; D003670:Deer; D004198:Disease Susceptibility; D016643:Encephalopathy, Bovine Spongiform / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D058507:Host Specificity / Q000235:genetics; D006801:Humans; D018621:PrPC Proteins / Q000737:chemistry / Q000235:genetics* / Q000472:pathogenicity*; D017096:Prion Diseases / Q000209:etiology* / Q000235:genetics / Q000378:metabolism; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D017386:Sequence Homology, Amino Acid; D034081:Wasting Disease, Chronic / Q000209:etiology / Q000235:genetics / Q000378:metabolism
chemical_list: D018621:PrPC Proteins