Dataset Information

Unique Structural Features of Mule Deer Prion Protein Provide Insights into Chronic Wasting Disease.

ABSTRACT: Chronic wasting disease (CWD) is a highly infectious prion disease of cervids. Accumulation of prions, the disease-specific structural conformers of the cellular prion protein (PrPC), in the central nervous system, is the key pathological event of the disorder. The analysis of cervid PrPC sequences revealed the existence of polymorphism at position 226, in which deer PrP contains glutamine (Q), whereas elk PrP contains glutamate (E). The effects of this polymorphism on CWD are still unknown. We determined the high-resolution nuclear magnetic resonance structure of the mule deer prion protein that was compared to previously published PrP structures of elk and white-tailed deer. We found that the polymorphism Q226E could influence the long-range intramolecular interactions and packing of the ?2-?2 loop and the C-terminus of the ?3 helix of cervid PrP structures. This solvent-accessible epitope is believed to be involved in prion conversion. Additional differences were observed at the beginning of the well-defined C-terminus domain, in the ?2-?3 region, and in its interactions with the ?1 helix. Here, we highlight the importance of the PrP structure in prion susceptibility and how single amino acid differences might influence the overall protein folding.

SUBMITTER: Slapsak U

PROVIDER: S-EPMC6882122 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Unique Structural Features of Mule Deer Prion Protein Provide Insights into Chronic Wasting Disease.

Slapšak Urška U Salzano Giulia G Ilc Gregor G Giachin Gabriele G Bian Jifeng J Telling Glenn G Legname Giuseppe G Plavec Janez J

ACS omega 20191115 22

Chronic wasting disease (CWD) is a highly infectious prion disease of cervids. Accumulation of prions, the disease-specific structural conformers of the cellular prion protein (PrP<sup>C</sup>), in the central nervous system, is the key pathological event of the disorder. The analysis of cervid PrP<sup>C</sup> sequences revealed the existence of polymorphism at position 226, in which deer PrP contains glutamine (Q), whereas elk PrP contains glutamate (E). The effects of this polymorphism on CWD ...[more]

PMID: 31788624

Similar Datasets

Project description:Transmissible spongiform encephalopathies (TSEs), or prion diseases, are a uniformly fatal family of neurodegenerative diseases in mammals that includes chronic wasting disease (CWD) of cervids. The early and ante-mortem identification of TSE-infected individuals using conventional western blotting or immunohistochemistry (IHC) has proven difficult, as the levels of infectious prions in readily obtainable samples, including blood and bodily fluids, are typically beyond the limits of detection. The development of amplification-based seeding assays has been instrumental in the detection of low levels of infectious prions in clinical samples. In the present study, we evaluated the cerebrospinal fluid (CSF) of CWD-exposed (n=44) and naïve (n=4) deer (n=48 total) for CWD prions (PrP(d)) using two amplification assays: serial protein misfolding cyclic amplification with polytetrafluoroethylene beads (sPMCAb) and real-time quaking induced conversion (RT-QuIC) employing a truncated Syrian hamster recombinant protein substrate. Samples were evaluated blindly in parallel with appropriate positive and negative controls. Results from amplification assays were compared to one another and to obex immunohistochemistry, and were correlated to available clinical histories including CWD inoculum source (e.g. saliva, blood), genotype, survival period, and duration of clinical signs. We found that both sPMCAb and RT-QuIC were capable of amplifying CWD prions from cervid CSF, and results correlated well with one another. Prion seeding activity in either assay was observed in approximately 50% of deer with PrP(d) detected by IHC in the obex region of the brain. Important predictors of amplification included duration of clinical signs and time of first tonsil biopsy positive results, and ultimately the levels of PrP(d) identified in the obex by IHC. Based on our findings, we expect that both sPMCAb and RT-QuIC may prove to be useful detection assays for the detection of prions in CSF.

Project description:Transmission of chronic wasting disease (CWD) between cervids is influenced by the primary structure of the host cellular prion protein (PrP(C)). In white-tailed deer, PRNP alleles encode the polymorphisms Q95 G96 (wild type [wt]), Q95 S96 (referred to as the S96 allele), and H95 G96 (referred to as the H95 allele), which differentially impact CWD progression. We hypothesize that the transmission of CWD prions between deer expressing different allotypes of PrP(C) modifies the contagious agent affecting disease spread. To evaluate the transmission properties of CWD prions derived experimentally from deer of four PRNP genotypes (wt/wt, S96/wt, H95/wt, or H95/S96), transgenic (tg) mice expressing the wt allele (tg33) or S96 allele (tg60) were challenged with these prion agents. Passage of deer CWD prions into tg33 mice resulted in 100% attack rates, with the CWD H95/S96 prions having significantly longer incubation periods. The disease signs and neuropathological and protease-resistant prion protein (PrP-res) profiles in infected tg33 mice were similar between groups, indicating that a prion strain (Wisc-1) common to all CWD inocula was amplified. In contrast, tg60 mice developed prion disease only when inoculated with the H95/wt and H95/S96 CWD allotypes. Serial passage in tg60 mice resulted in adaptation of a novel CWD strain (H95(+)) with distinct biological properties. Transmission of first-passage tg60CWD-H95(+) isolates into tg33 mice, however, elicited two prion disease presentations consistent with a mixture of strains associated with different PrP-res glycotypes. Our data indicate that H95-PRNP heterozygous deer accumulated two CWD strains whose emergence was dictated by the PrP(C) primary structure of the recipient host. These findings suggest that CWD transmission between cervids expressing distinct PrP(C) molecules results in the generation of novel CWD strains.CWD prions are contagious among wild and captive cervids in North America and in South Korea. We present data linking the amino acid variant Q95H in white-tailed deer cellular prion protein (PrP(C)) to the emergence of a novel CWD strain (H95(+)). We show that, upon infection, deer expressing H95-PrP(C) molecules accumulated a mixture of CWD strains that selectively propagated depending on the PRNP genotype of the host in which they were passaged. Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95(+) CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD.

Project description:Chronic wasting disease (CWD), a transmissible prion disease that affects elk and deer, poses new challenges to animal and human health. Although the transmission of CWD to humans has not been proven, it remains a possibility. If this were to occur, it is important to know whether the "acquired" human prion disease would show a phenotype including the scrapie prion protein (PrP(Sc)) features that differ from those associated with human sporadic prion disease. In this study, we have compared the pathological profiles and PrP(Sc) characteristics in brains of CWD-affected elk and deer with those in subjects with sporadic Creutzfeldt-Jakob disease (CJD), as well as CJD-affected subjects who might have been exposed to CWD, using histopathology, immunohistochemistry, immunoblotting, conformation stability assay, and N-terminal protein sequencing. Spongiform changes and intense PrP(Sc) staining were present in several brain regions of CWD-affected animals. Immunoblotting revealed three proteinase K (PK)-resistant bands in CWD, representing different glycoforms of PrP(Sc). The unglycosylated PK-resistant PrP(Sc) of CWD migrated at 21 kDa with an electrophoretic mobility similar to that of type 1 human PrP(Sc) present in sporadic CJD affecting subjects homozygous for methionine at codon 129 (sCJDMM1). N-terminal sequencing showed that the PK cleavage site of PrP(Sc) in CWD occurred at residues 82 and 78, similar to that of PrP(Sc) in sCJDMM1. Conformation stability assay also showed no significant difference between elk CWD PrP(Sc) and the PrP(Sc) species associated with sCJDMM1. However, there was a major difference in glycoform ratio of PrP(Sc) between CWD and sCJDMM1 affecting both subjects potentially exposed to CWD and non-exposed subjects. Moreover, PrP(Sc) of CWD exhibited a distinct constellation of glycoforms distinguishable from that of sCJDMM1 in two-dimensional immunoblots. These findings underline the importance of detailed PrP(Sc) characterization in trying to detect novel forms of acquired prion disease.

Dataset Information

Unique Structural Features of Mule Deer Prion Protein Provide Insights into Chronic Wasting Disease.

Publications

Unique Structural Features of Mule Deer Prion Protein Provide Insights into Chronic Wasting Disease.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets