Interaction of prion protein with small highly structured RNAs: detection and characterization of PrP-oligomers.
Conformational modification of normal prion protein (PrP(c)) to protease-resistant, beta-sheet rich, aggregates (PrP(sc)) is commonly accepted cause for prion diseases. On the other hand, several studies in recent years implicate soluble, protease-sensitive, oligomers of PrP(c) in neuronal damage. Previously, our group has shown that small, highly structured RNAs (shsRNAs), in conjunction with a serum factor, facilitated the conversion of hrPrP to a protease resistant, high molecular weight isoform. In the current study we demonstrate that shsRNAs, in the absence of the serum factor, generate soluble, protease-sensitive, and potentially toxic oligomers of ovrPrP. We have isolated a 500 kD oligomer by size exclusion chromatography of the reaction mixture and identified the accessible epitopes. The soluble PrP-oligomers were present in enhanced amounts in scrapie infected sheep brain and treating extracts of normal sheep brain with shsRNA resulted in oligomerization of endogenous PrP. Isolation, characterization of PrP-oligomers and their possible implication in prion diseases is discussed.
Vasan
Sara
S
Q-RNA, Inc.,, 3960 Broadway, New York, NY 10032, USA.
Mong
Phyllus Y
PY
Grossman
Abraham
A
D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D019286:Endopeptidase K / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011328:Prions / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012756:Sheep
D011328:Prions; D012313:RNA; D019286:Endopeptidase K