Heterogeneity of the Abnormal Prion Protein (PrPSc) of the Chandler Scrapie Strain

ABSTRACT Conversion of the normal protease-sensitive prion protein (PrP) to its abnormal protease-resistant isoform (PrP-res) is a major feature of the pathogenesis associated with transmissible spongiform encephalopathy (TSE) diseases. In previous experiments, PrP conversion was inhibited by a peptide composed of hamster PrP residues 109 to 141, suggesting that this region of the PrP molecule plays a crucial role in the conversion process. In this study, we used PrP-res derived from animals infected with two different mouse scrapie strains and one hamster scrapie strain to investigate the species specificity of these conversion reactions. Conversion of PrP was found to be completely species specific; however, despite having three amino acid differences, peptides corresponding to the hamster and mouse PrP sequences from residues 109 to 141 inhibited both the mouse and hamster PrP conversion systems equally. Furthermore, a peptide corresponding to hamster PrP residues 119 to 136, which was identical in both mouse and hamster PrP, was able to inhibit PrP-res formation in both the mouse and hamster cell-free systems as well as in scrapie-infected mouse neuroblastoma cell cultures. Because the PrP region from 119 to 136 is very conserved in most species, this peptide may have inhibitory effects on PrP conversion in a wide variety of TSE diseases.

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Characteristics of Prion Protein (PrPSc) in the Brains of Hamsters Inoculated Serially with a Mouse-passaged Scrapie Strain

Journal of Comparative Pathology ◽

10.1053/jcpa.1999.0348 ◽

2000 ◽

Vol 122 (2-3) ◽

pp. 123-130 ◽

Cited By ~ 3

Author(s):

K. Kimura ◽

M. Kubo ◽

T. Yokoyama

Keyword(s):

Prion Protein ◽

Scrapie Strain

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Prion Strain-Dependent Differences in Conversion of Mutant Prion Proteins in Cell Culture

Journal of Virology ◽

10.1128/jvi.00424-06 ◽

2006 ◽

Vol 80 (16) ◽

pp. 7854-7862 ◽

Cited By ~ 40

Author(s):

Ryuichiro Atarashi ◽

Valerie L. Sim ◽

Noriyuki Nishida ◽

Byron Caughey ◽

Shigeru Katamine

Keyword(s):

Prion Protein ◽

Prion Proteins ◽

Basic Amino Acid ◽

Inhibitory Effect ◽

Wild Type ◽

Prion Strain ◽

Potent Inhibitory Effect ◽

Scrapie Strain ◽

Infected Cells ◽

Strain Dependent

ABSTRACT Although the protein-only hypothesis proposes that it is the conformation of abnormal prion protein (PrPSc) that determines strain diversity, the molecular basis of strains remains to be elucidated. In the present study, we generated a series of mutations in the normal prion protein (PrPC) in which a single glutamine residue was replaced with a basic amino acid and compared their abilities to convert to PrPSc in cultured neuronal N2a58 cells infected with either the Chandler or 22L mouse-adapted scrapie strain. In mice, these strains generate PrPSc of the same sequence but different conformations, as judged by infrared spectroscopy. Substitutions at codons 97, 167, 171, and 216 generated PrPC that resisted conversion and inhibited the conversion of coexpressed wild-type PrP in both Chandler-infected and 22L-infected cells. Interestingly, substitutions at codons 185 and 218 gave strain-dependent effects. The Q185R and Q185K PrP were efficiently converted to PrPSc in Chandler-infected but not 22L-infected cells. Conversely, Q218R and Q218H PrP were converted only in 22L-infected cells. Moreover, the Q218K PrP exerted a potent inhibitory effect on the conversion of coexpressed wild-type PrP in Chandler-infected cells but had little effect on 22L-infected cells. These results show that two strains with the same PrP sequence but different conformations have differing abilities to convert the same mutated PrPC.

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Stability of murine scrapie strain 87V after passage in sheep and comparison with the CH1641 ovine strain

Journal of General Virology ◽

10.1099/jgv.0.000305 ◽

2015 ◽

Vol 96 (12) ◽

pp. 3703-3714 ◽

Cited By ~ 4

Author(s):

Lorenzo González ◽

Francesca Chianini ◽

Nora Hunter ◽

Scott Hamilton ◽

Louise Gibbard ◽

...

Keyword(s):

Prion Protein ◽

Biochemical Properties ◽

Survival Times ◽

Transgenic Mouse Line ◽

Disease Phenotypes ◽

Brain Material ◽

Scrapie Strain ◽

The Stability ◽

The Brain ◽

Combined Data

Breed- and prion protein (PRNP) genotype-related disease phenotype variability has been observed in sheep infected with the 87V murine scrapie strain. Therefore, the stability of this strain was tested by inoculating sheep-derived 87V brain material back into VM mice. As some sheep-adapted 87V disease phenotypes were reminiscent of CH1641 scrapie, transgenic mice (Tg338) expressing ovine prion protein (PrP) were inoculated with the same sheep-derived 87V sources and with CH1641. Although at first passage in VM mice the sheep-derived 87V sources showed some divergence from the murine 87V control, all the characteristics of murine 87V infection were recovered at second passage from all sheep sources. These included 100 % attack rates and indistinguishable survival times, lesion profiles, immunohistochemical features of disease-associated PrP accumulation in the brain and PrP biochemical properties. All sheep-derived 87V sources, as well as CH1641, were transmitted to Tg338 mice with identical clinical, pathological, immunohistochemical and biochemical features. While this might potentially indicate that sheep-adapted 87V and CH1641 are the same strain, profound divergences were evident, as murine 87V was unable to infect Tg338 mice but was lethal for VM mice, while the reverse was true for CH1641. These combined data suggest that: (i) murine 87V is stable and retains its properties after passage in sheep; (ii) it can be isolated from sheep showing a CH1641-like or a more conventional scrapie phenotype; and (iii) sheep-adapted 87V scrapie, with conventional or CH1641-like phenotype, is biologically distinct from experimental CH1641 scrapie, despite the fact that they behave identically in a single transgenic mouse line.

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Molecular Analysis of the Abnormal Prion Protein during Coinfection of Mice by Bovine Spongiform Encephalopathy and a Scrapie Agent

Journal of Virology ◽

10.1128/jvi.75.1.107-114.2001 ◽

2001 ◽

Vol 75 (1) ◽

pp. 107-114 ◽

Cited By ~ 33

Author(s):

Thierry G. M. Baron ◽

Anne-Gaelle Biacabe

Keyword(s):

Bovine Spongiform Encephalopathy ◽

Prion Protein ◽

Proteinase K ◽

Spongiform Encephalopathy ◽

Molecular Features ◽

Electrophoretic Mobilities ◽

Scrapie Agent ◽

Scrapie Strain ◽

Sheep Scrapie

ABSTRACT Molecular features of the proteinase K-resistant prion protein (PrP res) may discriminate among prion strains, and a specific signature could be found during infection by the infectious agent causing bovine spongiform encephalopathy (BSE). To investigate the molecular basis of BSE adaptation and selection, we established a model of coinfection of mice by both BSE and a sheep scrapie strain (C506M3). We now show that the PrP res features in these mice, characterized by glycoform ratios and electrophoretic mobilities, may be undistinguishable from those found in mice infected with scrapie only, including when mice were inoculated by both strains at the same time and by the same intracerebral inoculation route. Western blot analysis using different antibodies against sequences near the putative N-terminal end of PrP res also demonstrated differences in the main proteinase K cleavage sites between mice showing either the BSE or scrapie PrP res profile. These results, which may be linked to higher levels of PrP res associated with infection by scrapie, were similar following a challenge by a higher dose of the BSE agent during coinfection by both strains intracerebrally. Whereas PrP res extraction methods used allowed us to distinguish type 1 and type 2 PrP res, differing, like BSE and scrapie, by their electrophoretic mobilities, in the same brain region of some patients with Creutzfeldt-Jakob disease, analysis of in vitro mixtures of BSE and scrapie brain homogenates did not allow us to distinguish BSE and scrapie PrP res. These results suggest that the BSE agent, the origin of which remains unknown so far but which may have arisen from a sheep scrapie agent, may be hidden by a scrapie strain during attempts to identify it by molecular studies and following transmission of the disease in mice.

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Acute cellular uptake of abnormal prion protein is cell type and scrapie-strain independent

Virology ◽

10.1016/j.virol.2008.07.006 ◽

2008 ◽

Vol 379 (2) ◽

pp. 284-293 ◽

Cited By ~ 32

Author(s):

Christopher S. Greil ◽

Ina M. Vorberg ◽

Anne E. Ward ◽

Kimberly D. Meade-White ◽

David A. Harris ◽

...

Keyword(s):

Prion Protein ◽

Cellular Uptake ◽

Cell Type ◽

Scrapie Strain

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Metallic prions

Biochemical Society Symposium ◽

10.1042/bss0710193 ◽

2004 ◽

Vol 71 ◽

pp. 193-202 ◽

Cited By ~ 9

Author(s):

David R Brown

Keyword(s):

Prion Protein ◽

Binding Capacity ◽

Normal Function ◽

Transmissible Spongiform Encephalopathies ◽

Published Data ◽

Normal Brain ◽

Copper Binding ◽

Loss Of Function ◽

Spongiform Encephalopathies ◽

The Brain

Prion diseases, also referred to as transmissible spongiform encephalopathies, are characterized by the deposition of an abnormal isoform of the prion protein in the brain. However, this aggregated, fibrillar, amyloid protein, termed PrPSc, is an altered conformer of a normal brain glycoprotein, PrPc. Understanding the nature of the normal cellular isoform of the prion protein is considered essential to understanding the conversion process that generates PrPSc. To this end much work has focused on elucidation of the normal function and activity of PrPc. Substantial evidence supports the notion that PrPc is a copper-binding protein. In conversion to the abnormal isoform, this Cu-binding activity is lost. Instead, there are some suggestions that the protein might bind other metals such as Mn or Zn. PrPc functions currently under investigation include the possibility that the protein is involved in signal transduction, cell adhesion, Cu transport and resistance to oxidative stress. Of these possibilities, only a role in Cu transport and its action as an antioxidant take into consideration PrPc's Cu-binding capacity. There are also more published data supporting these two functions. There is strong evidence that during the course of prion disease, there is a loss of function of the prion protein. This manifests as a change in metal balance in the brain and other organs and substantial oxidative damage throughout the brain. Thus prions and metals have become tightly linked in the quest to understand the nature of transmissible spongiform encephalopathies.

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