Prion propagation in mice expressing human and chimeric PrP transgenes implicates the interaction of cellular PrP with another protein.
Transgenic (Tg) mice expressing human (Hu) and chimeric prion protein (PrP) genes were inoculated with brain extracts from humans with inherited or sporadic prion disease to investigate the mechanism by which PrPC is transformed into PrPSc. Although Tg(HuPrP) mice expressed high levels of HuPrPC, they were resistant to human prions. They became susceptible to human prions upon ablation of the mouse (Mo) PrP gene. In contrast, mice expressing low levels of the chimeric transgene were susceptible to human prions and registered only a modest decrease in incubation times upon MoPrP gene disruption. These and other findings argue that a species-specific macromolecule, provisionally designated protein X, participates in prion formation. While the results demonstrate that PrPSc binds to PrPC in a region delimited by codons 96 to 167, they also suggest that PrPC binds protein X through residues near the C-terminus. Protein X might function as a molecular chaperone in the formation of PrPSc.
Telling
G C
GC
Department of Neurology, University of California, San Francisco 94143, USA.
Scott
M
M
Mastrianni
J
J
Gabizon
R
R
Torchia
M
M
Cohen
F E
FE
DeArmond
S J
SJ
Prusiner
S B
SB
D000818:Animals; D001483:Base Sequence; D006224:Cricetinae; D004198:Disease Susceptibility; D015870:Gene Expression; D016098:Gerstmann-Straussler-Scheinker Disease / Q000235:genetics; D006801:Humans; D046911:Macromolecular Substances; D008647:Mesocricetus / Q000235:genetics; D051379:Mice / Q000235:genetics; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018832:Molecular Chaperones / Q000502:physiology; D008969:Molecular Sequence Data; D018621:PrPC Proteins / Q000235:genetics / Q000378:metabolism*; D018620:PrPSc Proteins / Q000235:genetics / Q000378:metabolism*; D017096:Prion Diseases / Q000235:genetics; D011328:Prions / Q000235:genetics*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D019076:Transgenes
D046911:Macromolecular Substances; D018832:Molecular Chaperones; D018621:PrPC Proteins; D018620:PrPSc Proteins; D011328:Prions; D011993:Recombinant Fusion Proteins