title: N-terminal truncation of prion protein affects both formation and conformation of abnormal protease-resistant prion protein generated in vitro.
abstract: Transmissible spongiform encephalopathy diseases are characterized by conversion of the normal protease-sensitive host prion protein, PrP-sen, to an abnormal protease-resistant form, PrP-res. In the current study, deletions were introduced into the flexible tail of PrP-sen (23) to determine if this region was required for formation of PrP-res in a cell-free assay. PrP-res formation was significantly reduced by deletion of residues 34-94 relative to full-length hamster PrP. Deletion of another nineteen amino acids to residue 113 further reduced the amount of PrP-res formed. Furthermore, the presence of additional proteinase K cleavage sites indicated that deletion to residue 113 generated a protease-resistant product with an altered conformation. Conversion of PrP deletion mutants was also affected by post-translational modifications to PrP-sen. Conversion of unglycosylated PrP-sen appeared to alter both the amount and the conformation of protease-resistant PrP-res produced from N-terminally truncated PrP-sen. The N-terminal region also affected the ability of hamster PrP to block mouse PrP-res formation in scrapie-infected mouse neuroblastoma cells. Thus, regions within the flexible N-terminal tail of PrP influenced interactions required for both generating and disrupting PrP-res formation.
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, National Institutes of Health, Hamilton, Montana 59840, USA.
authors.forename: V A
authors.initials: VA
authors.lastname: Lawson
authors.forename: S A
authors.initials: SA
authors.lastname: Priola
authors.forename: K
authors.initials: K
authors.lastname: Wehrly
authors.forename: B
authors.initials: B
authors.lastname: Chesebro
mesh_terms: D000818:Animals; D002474:Cell-Free System; D006224:Cricetinae; D010450:Endopeptidases / Q000378:metabolism*; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D066298:In Vitro Techniques; D051379:Mice; D008970:Molecular Weight; D011328:Prions / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D017384:Sequence Deletion
chemical_list: D017261:Glycosylphosphatidylinositols; D011328:Prions; D010450:Endopeptidases