1
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Pal S, Udgaonkar JB. Mutations of evolutionarily conserved aromatic residues suggest that misfolding of the mouse prion protein may commence in multiple ways. J Neurochem 2023; 167:696-710. [PMID: 37941487 DOI: 10.1111/jnc.16007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
The misfolding of the mammalian prion protein from its α-helix rich cellular isoform to its β-sheet rich infectious isoform is associated with several neurodegenerative diseases. The determination of the structural mechanism by which misfolding commences, still remains an unsolved problem. In the current study, native-state hydrogen exchange coupled with mass spectrometry has revealed that the N state of the mouse prion protein (moPrP) at pH 4 is in dynamic equilibrium with multiple partially unfolded forms (PUFs) capable of initiating misfolding. Mutation of three evolutionarily conserved aromatic residues, Tyr168, Phe174, and Tyr217 present at the interface of the β2-α2 loop and the C-terminal end of α3 in the structured C-terminal domain of moPrP significantly destabilize the native state (N) of the protein. They also reduce the free energy differences between the N state and two PUFs identified as PUF1 and PUF2**. It is shown that PUF2** in which the β2-α2 loop and the C-terminal end of α3 are disordered, has the same stability as the previously identified PUF2*, but to have a very different structure. Misfolding can commence from both PUF1 and PUF2**, as it can from PUF2*. Hence, misfolding can commence and proceed in multiple ways from structurally distinct precursor conformations. The increased extents to which PUF1 and PUF2** are populated at equilibrium in the case of the mutant variants, greatly accelerate their misfolding. The results suggest that the three aromatic residues may have been evolutionarily selected to impede the misfolding of moPrP.
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Affiliation(s)
- Suman Pal
- Indian Institute of Science Education and Research Pune, Pune, India
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2
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Cembran A, Fernandez-Funez P. Intrinsic determinants of prion protein neurotoxicity in Drosophila: from sequence to (dys)function. Front Mol Neurosci 2023; 16:1231079. [PMID: 37645703 PMCID: PMC10461008 DOI: 10.3389/fnmol.2023.1231079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/02/2023] [Indexed: 08/31/2023] Open
Abstract
Prion diseases are fatal brain disorders characterized by deposition of insoluble isoforms of the prion protein (PrP). The normal and pathogenic structures of PrP are relatively well known after decades of studies. Yet our current understanding of the intrinsic determinants regulating PrP misfolding are largely missing. A 3D subdomain of PrP comprising the β2-α2 loop and helix 3 contains high sequence and structural variability among animals and has been proposed as a key domain regulating PrP misfolding. We combined in vivo work in Drosophila with molecular dynamics (MD) simulations, which provide additional insight to assess the impact of candidate substitutions in PrP from conformational dynamics. MD simulations revealed that in human PrP WT the β2-α2 loop explores multiple β-turn conformations, whereas the Y225A (rabbit PrP-like) substitution strongly favors a 310-turn conformation, a short right-handed helix. This shift in conformational diversity correlates with lower neurotoxicity in flies. We have identified additional conformational features and candidate amino acids regulating the high toxicity of human PrP and propose a new strategy for testing candidate modifiers first in MD simulations followed by functional experiments in flies. In this review we expand on these new results to provide additional insight into the structural and functional biology of PrP through the prism of the conformational dynamics of a 3D domain in the C-terminus. We propose that the conformational dynamics of this domain is a sensitive measure of the propensity of PrP to misfold and cause toxicity. This provides renewed opportunities to identify the intrinsic determinants of PrP misfolding through the contribution of key amino acids to different conformational states by MD simulations followed by experimental validation in transgenic flies.
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Affiliation(s)
- Alessandro Cembran
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, MN, United States
| | - Pedro Fernandez-Funez
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, United States
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3
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Manka SW, Wenborn A, Betts J, Joiner S, Saibil HR, Collinge J, Wadsworth JDF. A structural basis for prion strain diversity. Nat Chem Biol 2023; 19:607-613. [PMID: 36646960 PMCID: PMC10154210 DOI: 10.1038/s41589-022-01229-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 11/18/2022] [Indexed: 01/17/2023]
Abstract
Recent cryogenic electron microscopy (cryo-EM) studies of infectious, ex vivo, prion fibrils from hamster 263K and mouse RML prion strains revealed a similar, parallel in-register intermolecular β-sheet (PIRIBS) amyloid architecture. Rungs of the fibrils are composed of individual prion protein (PrP) monomers that fold to create distinct N-terminal and C-terminal lobes. However, disparity in the hamster/mouse PrP sequence precludes understanding of how divergent prion strains emerge from an identical PrP substrate. In this study, we determined the near-atomic resolution cryo-EM structure of infectious, ex vivo mouse prion fibrils from the ME7 prion strain and compared this with the RML fibril structure. This structural comparison of two biologically distinct mouse-adapted prion strains suggests defined folding subdomains of PrP rungs and the way in which they are interrelated, providing a structural definition of intra-species prion strain-specific conformations.
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Affiliation(s)
- Szymon W Manka
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - Adam Wenborn
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - Jemma Betts
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - Susan Joiner
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - Helen R Saibil
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, UK.
| | - John Collinge
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK.
| | - Jonathan D F Wadsworth
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK.
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4
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Šulskis D, Šneiderienė G, Žiaunys M, Smirnovas V. The seeding barrier between human and Syrian hamster prion protein amyloid fibrils is determined by β2-α2 loop sequence elements. Int J Biol Macromol 2023; 238:124038. [PMID: 36921824 DOI: 10.1016/j.ijbiomac.2023.124038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/28/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Transmissive spongiform encephalopathies (TSE) are a group of neurodegenerative diseases caused by infectious protein particles, known as prions. Prions are formed from cellular prion proteins (PrP) and can be transmitted between different mammalian species. Subsequently, the host's PrPs are then converted to prions, followed by the onset of TSE. Interspecies prion infectivity is governed by the amino acid sequence differences of PrPs and prions' inability to replicate in a host is termed a species barrier. Here, we investigated the amino acid sequence determinants of species barrier between recombinant human (rHuPrP) and hamster (rShaPrP) prion protein amyloid fibrils. We discovered that a unidirectional species barrier between rShaPrP and rHuPrP amyloid fibrils exists. This barrier stems from the difference of amino acid sequences in the conserved β2-α2 loop region. Our results revealed that individual amino acids in the β2-α2 loop region are critical for overcoming the barrier between human and hamster prion protein amyloid fibrils in vitro. Furthermore, the barrier was only possible to observe through aggregation kinetics, as the secondary structure rHuPrP fibrils was not affected by the cross-seeding. Overall, we demonstrated the mechanistic pathway behind this interspecies barrier phenomenon, which increases our understanding of prion-related disease development.
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Affiliation(s)
- Darius Šulskis
- Amyloid Research Sector, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania.
| | - Greta Šneiderienė
- Amyloid Research Sector, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
| | - Mantas Žiaunys
- Amyloid Research Sector, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
| | - Vytautas Smirnovas
- Amyloid Research Sector, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
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5
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Molecular insights into the critical role of gallate moiety of green tea catechins in modulating prion fibrillation, cellular internalization, and neuronal toxicity. Int J Biol Macromol 2022; 223:755-765. [PMID: 36368361 DOI: 10.1016/j.ijbiomac.2022.11.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/01/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs) or prion diseases are fatal neurodegenerative diseases with no approved therapeutics. TSE pathology is characterized by abnormal accumulation of amyloidogenic and infectious prion protein conformers (PrPSc) in the central nervous system. Herein, we examined the role of gallate group in green tea catechins in modulating the aggregation of human prion protein (HuPrP) using two green tea constituents i.e., epicatechin 3-gallate (EC3G; with intact gallate ring) and epigallocatechin (EGC; without gallate ring). Molecular docking indicated distinct differences in hydrogen bonding and hydrophobic interactions of EC3G and EGC at the β2-α2 loop of HuPrP. These differences were substantiated by 44-fold higher KD for EC3G as compared to EGC with the former significantly reducing Thioflavin T (ThT) binding aggregates of HuPrP. Conformational alterations in HuPrP aggregates were validated by particle sizing, AFM analysis and A11 and OC conformational antibodies. As compared to EGC, EC3G showed relatively higher reduction in toxicity and cellular internalization of HuPrP oligomers in Neuro-2a cells. Additionally, EC3G also displayed higher fibril disaggregating properties as observed by ThT kinetics and electron microscopy. Our observations were supported by molecular dynamics (MD) simulations that showed markedly reduced α2-α3 and β2-α2 loop mobilities in presence of EC3G that may lead to constriction of HuPrP conformational space with lowered β-sheet conversion. In totality, gallate moiety of catechins play key role in modulating HuPrP aggregation, and toxicity and could be a new structural motif for designing therapeutics against prion diseases and other neurodegenerative disorders.
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6
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Mollica L, Giachin G. Recognition Mechanisms between a Nanobody and Disordered Epitopes of the Human Prion Protein: An Integrative Molecular Dynamics Study. J Chem Inf Model 2022; 63:531-545. [PMID: 36580661 PMCID: PMC9875307 DOI: 10.1021/acs.jcim.2c01062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Immunotherapy using antibodies to target the aggregation of flexible proteins holds promise for therapeutic interventions in neurodegenerative diseases caused by protein misfolding. Prions or PrPSc, the causal agents of transmissible spongiform encephalopathies (TSE), represent a model target for immunotherapies as TSE are prototypical protein misfolding diseases. The X-ray crystal structure of the wild-type (WT) human prion protein (HuPrP) bound to a camelid antibody fragment, denoted as Nanobody 484 (Nb484), has been previously solved. Nb484 was found to inhibit prion aggregation in vitro through a unique mechanism of structural stabilization of two disordered epitopes, that is, the palindromic motif (residues 113-120) and the β2-α2 loop region (residues 164-185). The study of the structural basis for antibody recognition of flexible proteins requires appropriate sampling techniques for the identification of conformational states occurring in disordered epitopes. To elucidate the Nb484-HuPrP recognition mechanisms, here we applied molecular dynamics (MD) simulations complemented with available NMR and X-ray crystallography data collected on the WT HuPrP to describe the conformational spaces occurring on HuPrP prior to Nb484 binding. We observe the experimentally determined binding competent conformations within the ensembles of pre-existing conformational states in solution before binding. We also described the Nb484 recognition mechanisms in two HuPrP carrying a polymorphism (E219K) and a TSE-causing mutation (V210I). Our hybrid approaches allow the identification of dynamic conformational landscapes existing on HuPrP and highly characterized by molecular disorder to identify physiologically relevant and druggable transitions.
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Affiliation(s)
- Luca Mollica
- Department
of Medical Biotechnology and Translational Medicine, University of Milan, Segrate, 20090 Milan, Italy,
| | - Gabriele Giachin
- Department
of Chemical Sciences (DiSC), University
of Padua, 35131 Padova, Italy,
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7
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The First Report of the Prion Protein Gene ( PRNP) Sequence in Pekin Ducks ( Anas platyrhynchos domestica): The Potential Prion Disease Susceptibility in Ducks. Genes (Basel) 2021; 12:genes12020193. [PMID: 33525657 PMCID: PMC7911840 DOI: 10.3390/genes12020193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/15/2021] [Accepted: 01/26/2021] [Indexed: 11/28/2022] Open
Abstract
Pathogenic prion protein (PrPSc), converted from normal prion protein (PrPC), causes prion disease. Although prion disease has been reported in several mammalian species, chickens are known to show strong resistance to prion diseases. In addition to chickens, the domestic duck occupies a large proportion in the poultry industry and may be regarded as a potential resistant host against prion disease. However, the DNA sequence of the prion protein gene (PRNP) has not been reported in domestic ducks. Here, we performed amplicon sequencing targeting the duck PRNP gene with the genomic DNA of Pekin ducks. In addition, we aligned the PrP sequence of the Pekin duck with that of various species using ClustalW2 and carried out phylogenetic analysis using Molecular Evolutionary Genetics Analysis X (MEGA X). We also constructed the structural modeling of the tertiary and secondary structures in avian PrP using SWISS-MODEL. Last, we investigated the aggregation propensity on Pekin duck PrP using AMYCO. We first reported the DNA sequence of the PRNP gene in Pekin ducks and found that the PrP sequence of Pekin ducks is more similar to that of geese than to that of chickens and mallards (wild ducks). Interestingly, Pekin duck PrP showed a high proportion of β-sheets compared to that of chicken PrP, and a high aggregation propensity compared to that of avian PrPs. However, Pekin duck PrP with substitutions of chicken-specific amino acids showed reduced aggregation propensities. To the best of our knowledge, this is the first report on the genetic characteristics of the PRNP sequence in Pekin ducks.
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8
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Sirohi PR, Kumari A, Admane N, Somvanshi P, Grover A. The polyphenolic phytoalexin polydatin inhibits amyloid aggregation of recombinant human prion protein. RSC Adv 2021; 11:25901-25911. [PMID: 35479435 PMCID: PMC9037109 DOI: 10.1039/d1ra01891d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/22/2021] [Indexed: 12/01/2022] Open
Abstract
Prion diseases involve misfolded and highly infectious aggregates of prion protein (PrPSc) which forms amyloid plaques leading to fatal neurodegeneration. The absence of clinically proven therapeutics makes the discovery of effective remedial interventions a prime concern. Herein, we report novel prion intervention by the polyphenolic phytoalexin, polydatin which binds with moderate affinity to the recombinant protease resistant core of human prion protein, encompassing the sequence 90–231 (rPrPres) and inhibits its conversion into the highly neurotoxic forms. An extensive evaluation using biophysical techniques revealed that polydatin incubated rPrPres samples generate off-pathway oligomers having reduced cross-β sheet signature, and relatively smaller in size than the native rPrPres oligomers. The detailed structural analysis using molecular dynamics simulations elucidated the induction of antagonistic mobilities in the β2–α2 loop, α3 helix and the N-terminal amyloidogenic region of prions. This study puts forward novel prion fibrillogenesis inhibitory potential of polydatin, specifically by stabilizing the N-terminal amyloidogenic region. Collectively our results affirm the importance of polydatin in crippling the prion pathogenesis and may serve as a structural scaffold for designing novel therapeutic agents targeting amyloidogenic transition in prions. Polydatin is found to be a pharmacologically-significant scaffold that can bind to the rPrPres repertoire and inhibit its conversion to the highly infectious and neurotoxic PrPSc-like form, thus acting like a promising anti-prion drug lead.![]()
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Affiliation(s)
- Preeti Rana Sirohi
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
- Department of Biotechnology
| | - Anchala Kumari
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
| | - Nikita Admane
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
| | - Pallavi Somvanshi
- School of Computational and Integrative Sciences
- Jawaharlal Nehru University
- New Delhi
- India
- Special Centre of Systems Medicine
| | - Abhinav Grover
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
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9
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Espinosa JC, Marín-Moreno A, Aguilar-Calvo P, Torres JM. Met 166 -Glu 168 residues in human PrP β2-α2 loop account for evolutionary resistance to prion infection. Neuropathol Appl Neurobiol 2020; 47:506-518. [PMID: 33253417 PMCID: PMC8247420 DOI: 10.1111/nan.12676] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 11/06/2020] [Accepted: 11/17/2020] [Indexed: 11/30/2022]
Abstract
Aims The amino acid sequence of prion protein (PrP) is a key determinant in the transmissibility of prion diseases. While PrP sequence is highly conserved among mammalian species, minor changes in the PrP amino acid sequence may confer alterations in the transmissibility of prion diseases. Classical bovine spongiform encephalopathy (C‐BSE) is the only zoonotic prion strain reported to date causing variant Creutzfeldt‐Jacob disease (vCJD) in humans, although experimental transmission points to atypical L‐BSE and some classical scrapie isolates as also zoonotic. The precise molecular elements in the human PrP sequence that limit the transmissibility of prion strains such as sheep/goat scrapie or cervid chronic wasting disease (CWD) are not well known. Methods The transmissibility of a panel of diverse prions from different species was compared in transgenic mice expressing either wild‐type human PrPC (MDE‐HuTg340) or a mutated human PrPC harbouring Val166‐Gln168 amino acid changes (VDQ‐HuTg372) in the β2‐α2 loop instead of Met166‐Glu168 wild‐type variants. Results VDQ‐HuTg372 mice were more susceptible to prions than MDE‐HuTg340 mice in a strain‐dependent manner. Conclusions Met166‐Glu168 amino acid residues present in wild‐type human PrPC are molecular determinants that limit the propagation of most prion strains assayed in the human PrP context.
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Affiliation(s)
| | - Alba Marín-Moreno
- Centro de Investigación en Sanidad Animal (INIA-CISA), Madrid, Spain
| | | | - Juan María Torres
- Centro de Investigación en Sanidad Animal (INIA-CISA), Madrid, Spain
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Cullingham CI, Peery RM, Dao A, McKenzie DI, Coltman DW. Predicting the spread-risk potential of chronic wasting disease to sympatric ungulate species. Prion 2020; 14:56-66. [PMID: 32008428 PMCID: PMC7009333 DOI: 10.1080/19336896.2020.1720486] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 02/08/2023] Open
Abstract
Wildlife disease incidence is increasing, resulting in negative impacts on the economy, biodiversity, and potentially human health. Chronic wasting disease (CWD) is a fatal, transmissible spongiform encephalopathy of cervids (wild and captive) which continues to spread geographically resulting in exposure to potential new host species. The disease agent (PrPCWD) is a misfolded conformer of the cellular prion protein (PrPC). In Canada, the disease is endemic in Alberta and Saskatchewan, affecting mule and white-tail deer, with lesser impact on elk and moose. As the disease continues to expand, additional wild ungulate species including bison, bighorn sheep, mountain goat, and pronghorn antelope may be exposed. To better understand the species-barrier, we reviewed the current literature on taxa naturally or experimentally exposed to CWD to identify susceptible and resistant species. We created a phylogeny of these taxa using cytochrome B and found that CWD susceptibility followed the species phylogeny. Using this phylogeny we estimated the probability of CWD susceptibility for wild ungulate species. We then compared PrPC amino acid polymorphisms among these species to identify which sites segregated between susceptible and resistant species. We identified sites that were significantly associated with susceptibility, but they were not fully discriminating. Finally, we sequenced Prnp from 578 wild ungulates to further evaluate their potential susceptibility. Together, these data suggest the host-range for CWD will potentially include pronghorn, mountain goat and bighorn sheep, but bison are likely to be more resistant. These findings highlight the need for monitoring potentially susceptible species as CWD continues to expand.
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Affiliation(s)
- Catherine I. Cullingham
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
- Department of Biology, Carleton University, Ottawa, Canada
| | - Rhiannon M. Peery
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Anh Dao
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Debbie I. McKenzie
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - David W. Coltman
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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11
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Shortening heparan sulfate chains prolongs survival and reduces parenchymal plaques in prion disease caused by mobile, ADAM10-cleaved prions. Acta Neuropathol 2020; 139:527-546. [PMID: 31673874 DOI: 10.1007/s00401-019-02085-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/10/2019] [Accepted: 10/13/2019] [Indexed: 12/18/2022]
Abstract
Cofactors are essential for driving recombinant prion protein into pathogenic conformers. Polyanions promote prion aggregation in vitro, yet the cofactors that modulate prion assembly in vivo remain largely unknown. Here we report that the endogenous glycosaminoglycan, heparan sulfate (HS), impacts prion propagation kinetics and deposition sites in the brain. Exostosin-1 haploinsufficient (Ext1+/-) mice, which produce short HS chains, show a prolonged survival and a redistribution of plaques from the parenchyma to vessels when infected with fibrillar prions, and a modest delay when infected with subfibrillar prions. Notably, the fibrillar, plaque-forming prions are composed of ADAM10-cleaved prion protein lacking a glycosylphosphatidylinositol anchor, indicating that these prions are mobile and assemble extracellularly. By analyzing the prion-bound HS using liquid chromatography-mass spectrometry (LC-MS), we identified the disaccharide signature of HS differentially bound to fibrillar compared to subfibrillar prions, and found approximately 20-fold more HS bound to the fibrils. Finally, LC-MS of prion-bound HS from human patients with familial and sporadic prion disease also showed distinct HS signatures and higher HS levels associated with fibrillar prions. This study provides the first in vivo evidence of an endogenous cofactor that accelerates prion disease progression and enhances parenchymal deposition of ADAM10-cleaved, mobile prions.
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12
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Espinosa JC, Marín-Moreno A, Aguilar-Calvo P, Benestad SL, Andreoletti O, Torres JM. Porcine Prion Protein as a Paradigm of Limited Susceptibility to Prion Strain Propagation. J Infect Dis 2020; 223:1103-1112. [PMID: 31919511 PMCID: PMC8006416 DOI: 10.1093/infdis/jiz646] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/20/2019] [Indexed: 11/14/2022] Open
Abstract
Although experimental transmission of bovine spongiform encephalopathy (BSE) to pigs and transgenic mice expressing pig cellular prion protein (PrPC) (porcine PrP [PoPrP]-Tg001) has been described, no natural cases of prion diseases in pig were reported. This study analyzed pig-PrPC susceptibility to different prion strains using PoPrP-Tg001 mice either as animal bioassay or as substrate for protein misfolding cyclic amplification (PMCA). A panel of isolates representatives of different prion strains was selected, including classic and atypical/Nor98 scrapie, atypical-BSE, rodent scrapie, human Creutzfeldt-Jakob-disease and classic BSE from different species. Bioassay proved that PoPrP-Tg001-mice were susceptible only to the classic BSE agent, and PMCA results indicate that only classic BSE can convert pig-PrPC into scrapie-type PrP (PrPSc), independently of the species origin. Therefore, conformational flexibility constraints associated with pig-PrP would limit the number of permissible PrPSc conformations compatible with pig-PrPC, thus suggesting that pig-PrPC may constitute a paradigm of low conformational flexibility that could confer high resistance to the diversity of prion strains.
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Affiliation(s)
- Juan Carlos Espinosa
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Alba Marín-Moreno
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | | | | | - Olivier Andreoletti
- UMR Institut National de la Recherche Agronomique (INRA)/École Nationale Vétérinaire de Toulouse (ENVT) 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
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13
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Abskharon R, Wang F, Wohlkonig A, Ruan J, Soror S, Giachin G, Pardon E, Zou W, Legname G, Ma J, Steyaert J. Structural evidence for the critical role of the prion protein hydrophobic region in forming an infectious prion. PLoS Pathog 2019; 15:e1008139. [PMID: 31815959 PMCID: PMC6922452 DOI: 10.1371/journal.ppat.1008139] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 12/19/2019] [Accepted: 10/09/2019] [Indexed: 11/18/2022] Open
Abstract
Prion or PrPSc is the proteinaceous infectious agent causing prion diseases in various mammalian species. Despite decades of research, the structural basis for PrPSc formation and prion infectivity remains elusive. To understand the role of the hydrophobic region in forming infectious prion at the molecular level, we report X-ray crystal structures of mouse (Mo) prion protein (PrP) (residues 89-230) in complex with a nanobody (Nb484). Using the recombinant prion propagation system, we show that the binding of Nb484 to the hydrophobic region of MoPrP efficiently inhibits the propagation of proteinase K resistant PrPSc and prion infectivity. In addition, when added to cultured mouse brain slices in high concentrations, Nb484 exhibits no neurotoxicity, which is drastically different from other neurotoxic anti-PrP antibodies, suggesting that the Nb484 can be a potential therapeutic agent against prion disease. In summary, our data provides the first structure-function evidence supporting a crucial role of the hydrophobic region of PrP in forming an infectious prion.
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Affiliation(s)
- Romany Abskharon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut Biotechnologie (VIB), Brussels, Belgium
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, United States of America
- National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
| | - Fei Wang
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, United States of America
- * E-mail: (FW); (JM); (JS)
| | - Alexandre Wohlkonig
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut Biotechnologie (VIB), Brussels, Belgium
| | - Juxin Ruan
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, United States of America
| | - Sameh Soror
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut Biotechnologie (VIB), Brussels, Belgium
- Center of Excellence, Helwan Structural Biology Research, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Gabriele Giachin
- Structural Biology Group, European Synchrotron Radiation Facility, Grenoble, France
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut Biotechnologie (VIB), Brussels, Belgium
| | - Wenquan Zou
- Departments of Pathology and Neurology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Jiyan Ma
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan, United States of America
- * E-mail: (FW); (JM); (JS)
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut Biotechnologie (VIB), Brussels, Belgium
- * E-mail: (FW); (JM); (JS)
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14
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Slapšak U, Salzano G, Ilc G, Giachin G, Bian J, Telling G, Legname G, Plavec J. Unique Structural Features of Mule Deer Prion Protein Provide Insights into Chronic Wasting Disease. ACS OMEGA 2019; 4:19913-19924. [PMID: 31788624 PMCID: PMC6882122 DOI: 10.1021/acsomega.9b02824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 11/06/2019] [Indexed: 06/10/2023]
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 β2-α2 loop and the C-terminus of the α3 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 α2-α3 region, and in its interactions with the α1 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.
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Affiliation(s)
- Urška Slapšak
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000 Ljubljana, Ljubljana, Slovenia
| | - Giulia Salzano
- Laboratory of Prion Biology, Department
of Neuroscience, Scuola Internazionale Superiore
di Studi Avanzati (SISSA), Via Bonomea 265, I-34136 Trieste, Trieste, Italy
| | - Gregor Ilc
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000 Ljubljana, Ljubljana, Slovenia
- EN-FIST Centre of Excellence, SI-1000 Ljubljana, Ljubljana, Slovenia
| | - Gabriele Giachin
- Laboratory of Prion Biology, Department
of Neuroscience, Scuola Internazionale Superiore
di Studi Avanzati (SISSA), Via Bonomea 265, I-34136 Trieste, Trieste, Italy
- Structural
Biology Group, European Synchrotron Radiation
Facility (ESRF), 38000 Grenoble, Auvergne-Rhône-Alpes, France
| | - Jifeng Bian
- Prion Research Center (PRC) and Department of Microbiology,
Immunology and Pathology, Colorado State
University, Fort Collins, Colorado 80525, United States
| | - Glenn Telling
- Prion Research Center (PRC) and Department of Microbiology,
Immunology and Pathology, Colorado State
University, Fort Collins, Colorado 80525, United States
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department
of Neuroscience, Scuola Internazionale Superiore
di Studi Avanzati (SISSA), Via Bonomea 265, I-34136 Trieste, Trieste, Italy
- ELETTRA-Sincrotrone Trieste S.C.p.A, 34149 Trieste, Friuli Venezia Giulia, Italy
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000 Ljubljana, Ljubljana, Slovenia
- EN-FIST Centre of Excellence, SI-1000 Ljubljana, Ljubljana, Slovenia
- Department of Chemistry and Biochemistry, Faculty of Chemistry and
Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Ljubljana, Slovenia
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15
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Espinosa JC, Comoy EE, Marin-Moreno A, Aguilar-Calvo P, Birling MC, Pitarch JL, Deslys JP, Torres JM. Transgenic mouse models expressing human and macaque prion protein exhibit similar prion susceptibility on a strain-dependent manner. Sci Rep 2019; 9:15699. [PMID: 31666632 PMCID: PMC6821920 DOI: 10.1038/s41598-019-52155-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 09/27/2019] [Indexed: 01/25/2023] Open
Abstract
Cynomolgus macaque has been used for the evaluation of the zoonotic potential of prion diseases, especially for classical-Bovine Spongiform Encephalopathy (classical-BSE) infectious agent. PrP amino acid sequence is considered to play a key role in the susceptibility to prion strains and only one amino acid change may alter this susceptibility. Macaque and human-PrP sequences have only nine amino acid differences, but the effect of these amino acid changes in the susceptibility to dissimilar prion strains is unknown. In this work, the transmissibility of a panel of different prions from several species was compared in transgenic mice expressing either macaque-PrPC (TgMac) or human-PrPC (Hu-Tg340). Similarities in the transmissibility of most prion strains were observed suggesting that macaque is an adequate model for the evaluation of human susceptibility to most of the prion strains tested. Interestingly, TgMac were more susceptible to classical-BSE strain infection than Hu-Tg340. This differential susceptibility to classical-BSE transmission should be taken into account for the interpretation of the results obtained in macaques. It could notably explain why the macaque model turned out to be so efficient (worst case model) until now to model human situation towards classical-BSE despite the limited number of animals inoculated in the laboratory experiments.
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Affiliation(s)
- Juan Carlos Espinosa
- Centro de Investigación en Sanidad Animal (INIA-CISA), 28130, Valdeolmos, Madrid, Spain.
| | - Emmanuel E Comoy
- CEA, Institut François Jacob, Université Paris-Saclay, 18 Route du Panorama, 92265, Fontenay-aux-Roses, France
| | - Alba Marin-Moreno
- Centro de Investigación en Sanidad Animal (INIA-CISA), 28130, Valdeolmos, Madrid, Spain
| | | | | | - José Luis Pitarch
- Centro de Investigación en Sanidad Animal (INIA-CISA), 28130, Valdeolmos, Madrid, Spain
| | - Jean-Philippe Deslys
- CEA, Institut François Jacob, Université Paris-Saclay, 18 Route du Panorama, 92265, Fontenay-aux-Roses, France
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (INIA-CISA), 28130, Valdeolmos, Madrid, Spain.
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16
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Bernardi L, Bruni AC. Mutations in Prion Protein Gene: Pathogenic Mechanisms in C-Terminal vs. N-Terminal Domain, a Review. Int J Mol Sci 2019; 20:E3606. [PMID: 31340582 PMCID: PMC6678283 DOI: 10.3390/ijms20143606] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/07/2019] [Accepted: 07/15/2019] [Indexed: 12/21/2022] Open
Abstract
Inherited mutations in the Prion protein (PrP), encoded by the PRNP gene, have been associated with autosomal dominant neurodegenerative disorders, such as Creutzfeldt-Jacob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), and Fatal Familial Insomnia (FFI). Notably, PRNP mutations have also been described in clinical pictures resembling other neurodegenerative diseases, such as frontotemporal dementia. Regarding the pathogenesis, it has been observed that these point mutations are located in the C-terminal region of the PRNP gene and, currently, the potential significance of the N-terminal domain has largely been underestimated. The purpose of this report is to review and provide current insights into the pathogenic mechanisms of PRNP mutations, emphasizing the differences between the C- and N-terminal regions and focusing, in particular, on the lesser-known flexible N-terminal, for which recent biophysical evidence has revealed a physical interaction with the globular C-terminal domain of the cellular prion protein (PrPC).
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Affiliation(s)
- Livia Bernardi
- Regional Neurogenetic Centre, ASP Catanzaro, 88046 Lamezia Terme (CZ), Italy
| | - Amalia C Bruni
- Regional Neurogenetic Centre, ASP Catanzaro, 88046 Lamezia Terme (CZ), Italy.
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17
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Harrathi C, Fernández-Borges N, Eraña H, Elezgarai SR, Venegas V, Charco JM, Castilla J. Insights into the Bidirectional Properties of the Sheep-Deer Prion Transmission Barrier. Mol Neurobiol 2018; 56:5287-5303. [PMID: 30592012 PMCID: PMC6614146 DOI: 10.1007/s12035-018-1443-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/30/2018] [Indexed: 02/06/2023]
Abstract
The large chronic wasting disease (CWD)-affected cervid population in the USA and Canada, and the risk of the disease being transmitted to humans through intermediate species, is a highly worrying issue that is still poorly understood. In this case, recombinant protein misfolding cyclic amplification was used to determine, in vitro, the relevance of each individual amino acid on cross-species prion transmission. Others and we have found that the β2-α2 loop is a key modulator of transmission barriers between species and markedly influences infection by sheep scrapie, bovine spongiform encephalopathy (BSE), or elk CWD. Amino acids that differentiate ovine and deer normal host prion protein (PrPC) and associated with structural rigidity of the loop β2-α2 (S173N, N177T) appear to confer resistance to some prion diseases. However, addition of methionine at codon 208 together with the previously described rigid loop substitutions seems to hide a key in this species barrier, as it makes sheep recombinant prion protein highly susceptible to CWD-induced misfolding. These studies indicate that interspecies prion transmission is not only governed just by the β2-α2 loop amino acid sequence but also by its interactions with the α3-helix as shown by substitution I208M. Transmissible spongiform encephalopathies, characterized by long incubation periods and spongiform changes associated with neuronal loss in the brain, have been described in several mammalian species appearing either naturally (scrapie in sheep and goats, bovine spongiform encephalopathy in cattle, chronic wasting disease in cervids, Creutzfeldt-Jakob disease in humans) or by experimental transmission studies (scrapie in mice and hamsters). Much of the pathogenesis of the prion diseases has been determined in the last 40 years, such as the etiological agent or the fact that prions occur as different strains that show distinct biological and physicochemical properties. However, there are many unanswered questions regarding the strain phenomenon and interspecies transmissibility. To assess the risk of interspecies transmission between scrapie and chronic wasting disease, an in vitro prion propagation method has been used. This technique allows to predict the amino acids preventing the transmission between sheep and deer prion diseases.
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Affiliation(s)
- Chafik Harrathi
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain
| | | | - Hasier Eraña
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain
| | - Saioa R Elezgarai
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain
| | - Vanessa Venegas
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain
| | - Jorge M Charco
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain
| | - Joaquín Castilla
- CIC bioGUNE, Parque tecnológico de Bizkaia, 48160, Derio, Bizkaia, Spain. .,IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Bizkaia, Spain.
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18
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Sanchez-Garcia J, Fernandez-Funez P. D159 and S167 are protective residues in the prion protein from dog and horse, two prion-resistant animals. Neurobiol Dis 2018; 119:1-12. [PMID: 30010001 DOI: 10.1016/j.nbd.2018.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 06/07/2018] [Accepted: 07/11/2018] [Indexed: 12/14/2022] Open
Abstract
Prion diseases are fatal neurodegenerative diseases caused by misfolding of the prion protein (PrP). These conditions affect humans and animals, including endemic forms in sheep and deer. Bovine, rodents, and many zoo mammals also developed prion diseases during the "mad-cow" epidemic in the 1980's. Interestingly, rabbits, horses, and dogs show unusual resistance to prion diseases, suggesting that specific sequence changes in the corresponding endogenous PrP prevents the accumulation of pathogenic conformations. In vitro misfolding assays and structural studies have identified S174, S167, and D159 as the key residues mediating the stability of rabbit, horse, and dog PrP, respectively. Here, we expressed the WT forms of rabbit, horse, and dog PrP in transgenic Drosophila and found that none of them is toxic. Replacing these key residues with the corresponding amino acids in hamster PrP showed that mutant horse (S167D) and dog (D159N) PrP are highly toxic, whereas mutant rabbit (S174 N) PrP is not. These results confirm the impact of S167 and D159 in local and long-range structural features in the globular domain of PrP that increase its stability, while suggesting the role of additional residues in the stability of rabbit PrP. Identifying these protective amino acids and the structural features that stabilize PrP can contribute to advance the field towards the development of therapies that halt or reverse the devastating effects of prion diseases.
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Affiliation(s)
- Jonatan Sanchez-Garcia
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
| | - Pedro Fernandez-Funez
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA.
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19
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Taguchi Y, Lu L, Marrero-Winkens C, Otaki H, Nishida N, Schatzl HM. Disulfide-crosslink scanning reveals prion-induced conformational changes and prion strain-specific structures of the pathological prion protein PrP Sc. J Biol Chem 2018; 293:12730-12740. [PMID: 29934306 PMCID: PMC6102138 DOI: 10.1074/jbc.ra117.001633] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/15/2018] [Indexed: 11/06/2022] Open
Abstract
Prions are composed solely of the pathological isoform (PrPSc) of the normal cellular prion protein (PrPC). Identification of different PrPSc structures is crucially important for understanding prion biology because the pathogenic properties of prions are hypothesized to be encoded in the structures of PrPSc However, these structures remain yet to be identified, because of the incompatibility of PrPSc with conventional high-resolution structural analysis methods. Previously, we reported that the region between the first and the second α-helix (H1∼H2) of PrPC might cooperate with the more C-terminal side region for efficient interactions with PrPSc From this starting point, we created a series of PrP variants with two cysteine substitutions (C;C-PrP) forming a disulfide-crosslink between H1∼H2 and the distal region of the third helix (Ctrm). We then assessed the conversion capabilities of the C;C-PrP variants in N2a cells infected with mouse-adapted scrapie prions (22L-ScN2a). Specifically, Cys substitutions at residues 165, 166, or 168 in H1∼H2 were combined with cysteine scanning along Ctrm residues 220-229. We found that C;C-PrPs are expressed normally with glycosylation patterns and subcellular localization similar to WT PrP, albeit differing in expression levels. Interestingly, some C;C-PrPs converted to protease-resistant isoforms in the 22L-ScN2a cells, but not in Fukuoka1 prion-infected cells. Crosslink patterns of convertible C;C-PrPs indicated a positional change of H1∼H2 toward Ctrm in PrPSc-induced conformational conversion. Given the properties of the C;C-PrPs reported here, we propose that these PrP variants may be useful tools for investigating prion strain-specific structures and structure-phenotype relationships of PrPSc.
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Affiliation(s)
- Yuzuru Taguchi
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada; Department of Molecular Microbiology and Immunology, Division of Cellular and Molecular Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523, Japan.
| | - Li Lu
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada; Calgary Prion Research Unit, University of Calgary, Calgary, Alberta, Canada
| | - Cristobal Marrero-Winkens
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada; Calgary Prion Research Unit, University of Calgary, Calgary, Alberta, Canada
| | - Hiroki Otaki
- Center for Bioinformatics and Molecular Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Noriyuki Nishida
- Department of Molecular Microbiology and Immunology, Division of Cellular and Molecular Biology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Hermann M Schatzl
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada; Calgary Prion Research Unit, University of Calgary, Calgary, Alberta, Canada.
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20
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Bera A, Biring S. A quantitative characterization of interaction between prion protein with nucleic acids. Biochem Biophys Rep 2018; 14:114-124. [PMID: 29872743 PMCID: PMC5986701 DOI: 10.1016/j.bbrep.2018.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/10/2018] [Accepted: 04/12/2018] [Indexed: 02/06/2023] Open
Abstract
Binding of recombinant prion protein with small highly structured RNAs, prokaryotic and eukaryotic prion protein mRNA pseudoknots, tRNA and polyA has been studied by the change in fluorescence anisotropy of the intrinsic tryptophan groups of the protein. The affinities of these RNAs to the prion protein and the number of sites where the protein binds to the nucleic acids do not vary appreciably although the RNAs have very different compositions and structures. The binding parameters do not depend upon pH of the solution and show a poor co-operativity. The reactants form larger nucleoprotein complexes at pH 5 compared to that at neutral pH. The electrostatic force between the protein and nucleic acids dominates the binding interaction at neutral pH. In contrast, nucleic acid interaction with the incipient nonpolar groups exposed from the structured region of the prion protein dominates the reaction at pH 5. Prion protein of a particular species forms larger complexes with prion protein mRNA pseudoknots of the same species. The structure of the pseudoknots and not their base sequences probably dominates their interaction with prion protein. Possibilities of the conversion of the prion protein to its infectious form in the cytoplasm by nucleic acids have been discussed.
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Affiliation(s)
- Alakesh Bera
- Infectiologie Animale et Santé Publique, Institut National de la Recherche Agronomique, 37380 Nouzilly, France
| | - Sajal Biring
- Department of Electronic Engineering and Organic Electronics Research Center, Ming-Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan
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21
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Molecular and Biological Compatibility with Host Alpha-Synuclein Influences Fibril Pathogenicity. Cell Rep 2018; 16:3373-3387. [PMID: 27653697 DOI: 10.1016/j.celrep.2016.08.053] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/17/2016] [Accepted: 08/16/2016] [Indexed: 02/03/2023] Open
Abstract
The accumulation and propagation of misfolded α-synuclein (α-Syn) is a central feature of Parkinson's disease and other synucleinopathies. Molecular compatibility between a fibrillar seed and its native protein state is a major determinant of amyloid self-replication. We show that cross-seeded aggregation of human (Hu) and mouse (Ms) α-Syn is bidirectionally restricted. Although fibrils formed by Hu-Ms-α-Syn chimeric mutants can overcome this inhibition in cell-free systems, sequence homology poorly predicts their efficiency in inducing α-Syn pathology in primary neurons or after intracerebral injection into wild-type mice. Chimeric α-Syn fibrils demonstrate enhanced or reduced pathogenicities compared with wild-type Hu- or Ms-α-Syn fibrils. Furthermore, α-Syn mutants induced to polymerize by fibrillar seeds inherit the functional properties of their template, suggesting that transferable pathogenic and non-pathogenic states likely influence the initial engagement between exogenous α-Syn seeds and endogenous neuronal α-Syn. Thus, transmission of synucleinopathies is regulated by biological processes in addition to molecular compatibility.
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22
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Kurt TD, Aguilar-Calvo P, Jiang L, Rodriguez JA, Alderson N, Eisenberg DS, Sigurdson CJ. Asparagine and glutamine ladders promote cross-species prion conversion. J Biol Chem 2017; 292:19076-19086. [PMID: 28931606 PMCID: PMC5704488 DOI: 10.1074/jbc.m117.794107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 09/01/2017] [Indexed: 11/06/2022] Open
Abstract
Prion transmission between species is governed in part by primary sequence similarity between the infectious prion aggregate, PrPSc, and the cellular prion protein of the host, PrPC A puzzling feature of prion formation is that certain PrPC sequences, such as that of bank vole, can be converted by a remarkably broad array of different mammalian prions, whereas others, such as rabbit, show robust resistance to cross-species prion conversion. To examine the structural determinants that confer susceptibility or resistance to prion conversion, we systematically tested over 40 PrPC variants of susceptible and resistant PrPC sequences in a prion conversion assay. Five key residue positions markedly impacted prion conversion, four of which were in steric zipper segments where side chains from amino acids tightly interdigitate in a dry interface. Strikingly, all five residue substitutions modulating prion conversion involved the gain or loss of an asparagine or glutamine residue. For two of the four positions, Asn and Gln residues were not interchangeable, revealing a strict requirement for either an Asn or Gln residue. Bank voles have a high number of Asn and Gln residues and a high Asn:Gln ratio. These findings suggest that a high number of Asn and Gln residues at specific positions may stabilize β-sheets and lower the energy barrier for cross-species prion transmission, potentially because of hydrogen bond networks from side chain amides forming extended Asn/Gln ladders. These data also suggest that multiple PrPC segments containing Asn/Gln residues may act in concert along a replicative interface to promote prion conversion.
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Affiliation(s)
- Timothy D Kurt
- From the Departments of Pathology and Medicine, University of California at San Diego, La Jolla, California 92093
| | - Patricia Aguilar-Calvo
- From the Departments of Pathology and Medicine, University of California at San Diego, La Jolla, California 92093
| | - Lin Jiang
- the Department of Neurology, UCLA, Los Angeles, California 90095, and
| | - José A Rodriguez
- the UCLA-DOE Institute, Howard Hughes Medical Institute, Los Angeles, California 90095
- the Molecular Biology Institute
- the Department of Chemistry and Biochemistry, and
| | - Nazilla Alderson
- From the Departments of Pathology and Medicine, University of California at San Diego, La Jolla, California 92093
| | - David S Eisenberg
- the UCLA-DOE Institute, Howard Hughes Medical Institute, Los Angeles, California 90095
- the Molecular Biology Institute
| | - Christina J Sigurdson
- From the Departments of Pathology and Medicine, University of California at San Diego, La Jolla, California 92093,
- the Department of Pathology, Immunology, and Microbiology, University of California at Davis, Davis, California 95616
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23
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Kanata E, Arsenakis M, Sklaviadis T. Caprine PrP variants harboring Asp-146, His-154 and Gln-211 alleles display reduced convertibility upon interaction with pathogenic murine prion protein in scrapie infected cells. Prion 2017; 10:391-408. [PMID: 27537339 DOI: 10.1080/19336896.2016.1199312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Scrapie, the prion disease of sheep and goats, is a devastating malady of small ruminants. Due to its infectious nature, epidemic outbreaks may occur in flocks/herds consisting of highly susceptible animals. Field studies identified scrapie-protective caprine PrP variants, harboring specific single amino acid changes (Met-142, Arg-143, Asp-146, Ser-146, His-154, Gln-211 and Lys-222). Their effects are under further evaluation, and aim to determine the most protective allele. We assessed some of these variants (Asp-146, His-154, Gln-211 and Lys-222), after their exogenous expression as murine-caprine chimeras in a scrapie- infected murine cell line. We report that exogenously expressed PrPs undergo conformational conversion upon interaction with the endogenous pathological murine prion protein (PrPSC), which results in the detection of goat-specific and partially PK-resistant moieties. These moieties display a PK-resistance pattern distinct from the one detected in natural goat scrapie cases. Within this cellular model, distinct conformational conversion potentials were assigned to the tested variants. Molecules carrying the Asp-146, His-154 and Gln-211 alleles showed significantly lower conversion levels compared to wild type, confirming their protective effects against scrapie. Although we utilized a heterologous conversion system, this is to our knowledge, the first study of caprine PrP variants in a cellular context of scrapie, that confirms the protective effects of some of the studied alleles.
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Affiliation(s)
- Eirini Kanata
- a Department of Genetics , Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki , Thessaloniki , Greece.,b School of Pharmacy , Aristotle University of Thessaloniki , Thessaloniki , Greece
| | - Minas Arsenakis
- a Department of Genetics , Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki , Thessaloniki , Greece
| | - Theodoros Sklaviadis
- b School of Pharmacy , Aristotle University of Thessaloniki , Thessaloniki , Greece
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24
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Abstract
Prions cause fatal neurodegenerative diseases in humans and animals and can be transmitted zoonotically. Chronic wasting disease (CWD) is a highly transmissible prion disease of wild deer and elk that affects cervids over extensive regions of the United States and Canada. The risk of cross-species CWD transmission has been experimentally evaluated in a wide array of mammals, including non-human primates and mouse models expressing human cellular prion protein. Here we review the determinants of cross-species CWD transmission, and propose a model that may explain a structural barrier for CWD transmission to humans.
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Affiliation(s)
- Timothy D Kurt
- a Departments of Pathology and Medicine , UC San Diego , La Jolla , CA , USA
| | - Christina J Sigurdson
- a Departments of Pathology and Medicine , UC San Diego , La Jolla , CA , USA.,b Department of Pathology, Immunology, and Microbiology , UC Davis , Davis , CA , USA
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25
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Seelig DM, Goodman PA, Skinner PJ. Potential approaches for heterologous prion protein treatment of prion diseases. Prion 2017; 10:18-24. [PMID: 26636482 PMCID: PMC4981202 DOI: 10.1080/19336896.2015.1123372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Prion diseases, or transmissible spongiform encephalopathies (TSEs) are progressive, fatal neurodegenerative diseases with no effective treatment. The pathology of these diseases involves the conversion of a protease sensitive form of the cellular prion protein (PrPC) into a protease resistant infectious form (PrPres). The efficiency of this conversion is predicated upon a number of factors, most notably a strong homology between cellular PrPC and PrPres. In our recently published study, we infected mice with the RML-Chandler strain of scrapie and treated them with heterologous hamster prion proteins. This treatment was seen to reduce clinical signs of prion disease, to delay the onset of clinical symptoms and to prolong survival. In this current article we discuss potential mechanisms of action of treatment with heterologous prion proteins. We also discuss potential extensions of these studies using a heterologous rabbit PrP-based treatment strategy or a peptide based strategy, and improvement of treatment delivery including a lentiviral-based system.
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Affiliation(s)
- Davis M Seelig
- a Veterinary Clinical Sciences Department , University of Minnesota , Saint Paul , MN , USA
| | - Patricia A Goodman
- b Veterinary and Biomedical Sciences Department , University of Minnesota , Saint Paul , MN , USA
| | - Pamela J Skinner
- b Veterinary and Biomedical Sciences Department , University of Minnesota , Saint Paul , MN , USA
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Complex folding and misfolding effects of deer-specific amino acid substitutions in the β2-α2 loop of murine prion protein. Sci Rep 2015; 5:15528. [PMID: 26490404 PMCID: PMC4614821 DOI: 10.1038/srep15528] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 09/22/2015] [Indexed: 01/09/2023] Open
Abstract
The β2-α2 loop of PrP(C) is a key modulator of disease-associated prion protein misfolding. Amino acids that differentiate mouse (Ser169, Asn173) and deer (Asn169, Thr173) PrP(C) appear to confer dramatically different structural properties in this region and it has been suggested that amino acid sequences associated with structural rigidity of the loop also confer susceptibility to prion disease. Using mouse recombinant PrP, we show that mutating residue 173 from Asn to Thr alters protein stability and misfolding only subtly, whilst changing Ser to Asn at codon 169 causes instability in the protein, promotes oligomer formation and dramatically potentiates fibril formation. The doubly mutated protein exhibits more complex folding and misfolding behaviour than either single mutant, suggestive of differential effects of the β2-α2 loop sequence on both protein stability and on specific misfolding pathways. Molecular dynamics simulation of protein structure suggests a key role for the solvent accessibility of Tyr168 in promoting molecular interactions that may lead to prion protein misfolding. Thus, we conclude that 'rigidity' in the β2-α2 loop region of the normal conformer of PrP has less effect on misfolding than other sequence-related effects in this region.
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Watts JC, Giles K, Patel S, Oehler A, DeArmond SJ, Prusiner SB. Evidence that bank vole PrP is a universal acceptor for prions. PLoS Pathog 2014; 10:e1003990. [PMID: 24699458 PMCID: PMC3974871 DOI: 10.1371/journal.ppat.1003990] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 01/28/2014] [Indexed: 12/29/2022] Open
Abstract
Bank voles are uniquely susceptible to a wide range of prion strains isolated from many different species. To determine if this enhanced susceptibility to interspecies prion transmission is encoded within the sequence of the bank vole prion protein (BVPrP), we inoculated Tg(M109) and Tg(I109) mice, which express BVPrP containing either methionine or isoleucine at polymorphic codon 109, with 16 prion isolates from 8 different species: humans, cattle, elk, sheep, guinea pigs, hamsters, mice, and meadow voles. Efficient disease transmission was observed in both Tg(M109) and Tg(I109) mice. For instance, inoculation of the most common human prion strain, sporadic Creutzfeldt-Jakob disease (sCJD) subtype MM1, into Tg(M109) mice gave incubation periods of ∼200 days that were shortened slightly on second passage. Chronic wasting disease prions exhibited an incubation time of ∼250 days, which shortened to ∼150 days upon second passage in Tg(M109) mice. Unexpectedly, bovine spongiform encephalopathy and variant CJD prions caused rapid neurological dysfunction in Tg(M109) mice upon second passage, with incubation periods of 64 and 40 days, respectively. Despite the rapid incubation periods, other strain-specified properties of many prion isolates—including the size of proteinase K–resistant PrPSc, the pattern of cerebral PrPSc deposition, and the conformational stability—were remarkably conserved upon serial passage in Tg(M109) mice. Our results demonstrate that expression of BVPrP is sufficient to engender enhanced susceptibility to a diverse range of prion isolates, suggesting that BVPrP may be a universal acceptor for prions. Prions are infectious proteins that cause devastating neurodegenerative diseases in both humans and animals. Unlike other rodents, bank voles are highly susceptible to prions from many different species, suggesting that bank voles do not impose a “species barrier,” which normally restricts the transmission of prions from one species to another. We were curious as to whether the unprecedented promiscuity of bank voles for prions is due to the specific prion protein sequence expressed, or to some other factor inherent to bank vole physiology. To answer this question, we inoculated transgenic mice that express bank vole prion protein [Tg(BVPrP) mice] with a diverse set of prions deriving from eight different species. Like bank voles, Tg(BVPrP) mice were highly susceptible to prions from all species tested, demonstrating that the BVPrP sequence mediates the enhanced susceptibility of bank voles to prions. Because the amino acid sequences of mouse and BVPrP differ at only eight positions, our results demonstrate that alterations to a small subset of residues within PrP can have a profound effect on the susceptibility of an organism to prions from another species.
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Affiliation(s)
- Joel C Watts
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| | - Kurt Giles
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| | - Smita Patel
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America
| | - Abby Oehler
- Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
| | - Stephen J DeArmond
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
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Abstract
Zoonotic prion transmission was reported after the bovine spongiform encephalopathy (BSE) epidemic, when >200 cases of prion disease in humans were diagnosed as variant Creutzfeldt-Jakob disease. Assessing the risk of cross-species prion transmission remains challenging. We and others have studied how specific amino acid residue differences between species impact prion conversion and have found that the β2-α2 loop region of the mouse prion protein (residues 165-175) markedly influences infection by sheep scrapie, BSE, mouse-adapted scrapie, deer chronic wasting disease, and hamster-adapted scrapie prions. The tyrosine residue at position 169 is strictly conserved among mammals and an aromatic side chain in this position is essential to maintain a 310-helical turn in the β2-α2 loop. Here we examined the impact of the Y169G substitution together with the previously described S170N, N174T "rigid loop" substitutions on cross-species prion transmission in vivo and in vitro. We found that transgenic mice expressing mouse PrP containing the triple-amino acid substitution completely resisted infection with two strains of mouse prions and with deer chronic wasting disease prions. These studies indicate that Y169 is important for prion formation, and they provide a strong indication that variation of the β2-α2 loop structure can modulate interspecies prion transmission.
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Kurt TD, Jiang L, Bett C, Eisenberg D, Sigurdson CJ. A proposed mechanism for the promotion of prion conversion involving a strictly conserved tyrosine residue in the β2-α2 loop of PrPC. J Biol Chem 2014; 289:10660-10667. [PMID: 24596090 DOI: 10.1074/jbc.m114.549030] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transmission of infectious prions into different host species requires compatible prion protein (PrP) primary structures, and even one heterologous residue at a pivotal position can block prion infection. Mapping the key amino acid positions that govern cross-species prion conversion has not yet been possible, although certain residue positions have been identified as restrictive, including residues in the β2-α2 loop region of PrP. To further define how β2-α2 residues impact conversion, we investigated residue substitutions in PrP(C) using an in vitro prion conversion assay. Within the β2-α2 loop, a tyrosine residue at position 169 is strictly conserved among mammals, and transgenic mice expressing mouse PrP having the Y169G, S170N, and N174T substitutions resist prion infection. To better understand the structural requirements of specific residues for conversion initiated by mouse prions, we substituted a diverse array of amino acids at position 169 of PrP. We found that the substitution of glycine, leucine, or glutamine at position 169 reduced conversion by ∼ 75%. In contrast, replacing tyrosine 169 with either of the bulky, aromatic residues, phenylalanine or tryptophan, supported efficient prion conversion. We propose a model based on a requirement for tightly interdigitating complementary amino acid side chains within specific domains of adjacent PrP molecules, known as "steric zippers," to explain these results. Collectively, these studies suggest that an aromatic residue at position 169 supports efficient prion conversion.
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Affiliation(s)
- Timothy D Kurt
- Department of Pathology and Medicine, University of California San Diego, La Jolla, California 92093
| | - Lin Jiang
- Department of Energy Institute for Genomics and Proteomics, Howard Hughes Medical Institute, and Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Cyrus Bett
- Department of Pathology and Medicine, University of California San Diego, La Jolla, California 92093
| | - David Eisenberg
- Department of Energy Institute for Genomics and Proteomics, Howard Hughes Medical Institute, and Molecular Biology Institute, UCLA, Los Angeles, California 90095
| | - Christina J Sigurdson
- Department of Pathology and Medicine, University of California San Diego, La Jolla, California 92093; Department of Pathology, Immunology, and Microbiology, University of California, Davis, California 95616.
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Molecular dynamics studies on the NMR and X-ray structures of rabbit prion proteins. J Theor Biol 2013; 342:70-82. [PMID: 24184221 DOI: 10.1016/j.jtbi.2013.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/25/2013] [Accepted: 10/09/2013] [Indexed: 12/27/2022]
Abstract
Prion diseases, traditionally referred to as transmissible spongiform encephalopathies (TSEs), are invariably fatal and highly infectious neurodegenerative diseases that affect a wide variety of mammalian species, manifesting as scrapie in sheep and goats, bovine spongiform encephalopathy (BSE or mad-cow disease) in cattle, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob diseases, Gerstmann-Sträussler-Scheinker syndrome, fatal familial insomnia, and kulu in humans, etc. These neurodegenerative diseases are caused by the conversion from a soluble normal cellular prion protein (PrP(C)) into insoluble abnormally folded infectious prions (PrP(Sc)), and the conversion of PrP(C) to PrP(Sc) is believed to involve conformational change from a predominantly α-helical protein to one rich in β-sheet structure. Such a conformational change may be amenable to study by molecular dynamics (MD) techniques. For rabbits, classical studies show that they have a low susceptibility to be infected by PrP(Sc), but recently it was reported that rabbit prions can be generated through saPMCA (serial automated Protein Misfolding Cyclic Amplification) in vitro and the rabbit prion is infectious and transmissible. In this paper, we first do a detailed survey on the research advances of rabbit prion protein (RaPrP) and then we perform MD simulations on the NMR and X-ray molecular structures of rabbit prion protein wild-type and mutants. The survey shows to us that rabbits were not challenged directly in vivo with other known prion strains and the saPMCA result did not pass the test of the known BSE strain of cattle. Thus, we might still look rabbits as a prion resistant species. MD results indicate that the three α-helices of the wild-type are stable under the neutral pH environment (but under low pH environment the three α-helices have been unfolded into β-sheets), and the three α-helices of the mutants (I214V and S173N) are unfolded into rich β-sheet structures under the same pH environment. In addition, we found an interesting result that the salt bridges such as ASP201-ARG155, ASP177-ARG163 contribute greatly to the structural stability of RaPrP.
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Leunda A, Van Vaerenbergh B, Baldo A, Roels S, Herman P. Laboratory activities involving transmissible spongiform encephalopathy causing agents: risk assessment and biosafety recommendations in Belgium. Prion 2013; 7:420-33. [PMID: 24055928 PMCID: PMC3904386 DOI: 10.4161/pri.26533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/13/2013] [Accepted: 09/18/2013] [Indexed: 11/19/2022] Open
Abstract
Since the appearance in 1986 of epidemic of bovine spongiform encephalopathy (BSE), a new form of neurological disease in cattle which also affected human beings, many diagnostic and research activities have been performed to develop detection and therapeutic tools. A lot of progress was made in better identifying, understanding and controlling the spread of the disease by appropriate monitoring and control programs in European countries. This paper reviews the recent knowledge on pathogenesis, transmission and persistence outside the host of prion, the causative agent of transmissible spongiform encephalopathies (TSE) in mammals with a particular focus on risk (re)assessment and management of biosafety measures to be implemented in diagnostic and research laboratories in Belgium. Also, in response to the need of an increasing number of European diagnostic laboratories stopping TSE diagnosis due to a decreasing number of TSE cases reported in the last years, decontamination procedures and a protocol for decommissioning TSE diagnostic laboratories is proposed.
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Affiliation(s)
- Amaya Leunda
- Biosafety and Biotechnology Unit; Institut Scientifique de Santé Publique; Brussels, Belgium
| | | | - Aline Baldo
- Biosafety and Biotechnology Unit; Institut Scientifique de Santé Publique; Brussels, Belgium
| | - Stefan Roels
- Orientation and Veterinary Support; National Reference Laboratory for TSE (Belgium & Luxemburg); Veterinary and Agrochemical Research Center; Brussels, Belgium
| | - Philippe Herman
- Biosafety and Biotechnology Unit; Institut Scientifique de Santé Publique; Brussels, Belgium
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Dutta A, Chen S, Surewicz WK. The effect of β2-α2 loop mutation on amyloidogenic properties of the prion protein. FEBS Lett 2013; 587:2918-23. [PMID: 23892077 DOI: 10.1016/j.febslet.2013.07.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/09/2013] [Accepted: 07/15/2013] [Indexed: 10/26/2022]
Abstract
Recent studies revealed that elk-like S170N/N174T mutation in mouse prion protein (moPrP), which results in an increased rigidity of β2-α2 loop, leads to a prion disease in transgenic mice. Here we characterized the effect of this mutation on biophysical properties of moPrP. Despite similar thermodynamic stabilities of wild type and mutant proteins, the latter was found to have markedly higher propensity to form amyloid fibrils. Importantly, this effect was observed even under fully denaturing conditions, indicating that the increased conversion propensity of the mutant protein is not due to loop rigidity but rather results from greater amyloidogenic potential of the amino acid sequence within the loop region of S170N/N174T moPrP.
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Affiliation(s)
- Arpana Dutta
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
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Kyle LM, John TR, Schätzl HM, Lewis RV. Introducing a rigid loop structure from deer into mouse prion protein increases its propensity for misfolding in vitro. PLoS One 2013; 8:e66715. [PMID: 23825561 PMCID: PMC3692500 DOI: 10.1371/journal.pone.0066715] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/09/2013] [Indexed: 12/20/2022] Open
Abstract
Prion diseases are fatal neurodegenerative disorders characterized by misfolding of the cellular prion protein (PrPc) into the disease-associated isoform (PrPSc) that has increased β-sheet content and partial resistance to proteolytic digestion. Prion diseases from different mammalian species have varying propensities for transmission upon exposure of an uninfected host to the infectious agent. Chronic Wasting Disease (CWD) is a highly transmissible prion disease that affects free ranging and farmed populations of cervids including deer, elk and moose, as well as other mammals in experimental settings. The molecular mechanisms allowing CWD to maintain comparatively high transmission rates have not been determined. Previous work has identified a unique structural feature in cervid PrP, a rigid loop between β-sheet 2 and α-helix 2 on the surface of the protein. This study was designed to test the hypothesis that the rigid loop has a direct influence on the misfolding process. The rigid loop was introduced into murine PrP as the result of two amino acid substitutions: S170N and N174T. Wild-type and rigid loop murine PrP were expressed in E. coli and purified. Misfolding propensity was compared for the two proteins using biochemical techniques and cell free misfolding and conversion systems. Murine PrP with a rigid loop misfolded in cell free systems with greater propensity than wild type murine PrP. In a lipid-based conversion assay, rigid loop PrP converted to a PK resistant, aggregated isoform at lower concentrations than wild-type PrP. Using both proteins as substrates in real time quaking-induced conversion, rigid loop PrP adopted a misfolded isoform more readily than wild type PrP. Taken together, these findings may help explain the high transmission rates observed for CWD within cervids.
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Affiliation(s)
- Leah M Kyle
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, United States of America
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Structural plasticity of the cellular prion protein and implications in health and disease. Proc Natl Acad Sci U S A 2013; 110:8549-54. [PMID: 23650394 DOI: 10.1073/pnas.1306178110] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two lines of transgenic mice expressing mouse/elk and mouse/horse prion protein (PrP) hybrids, which both form a well-structured β2-α2 loop in the NMR structures at 20 °C termed rigid-loop cellular prion proteins (RL-PrP(C)), presented with accumulation of the aggregated scrapie form of PrP in brain tissue, and the mouse/elk hybrid has also been shown to develop a spontaneous transmissible spongiform encephalopathy. Independently, there is in vitro evidence for correlations between the amino acid sequence in the β2-α2 loop and the propensity for conformational transitions to disease-related forms of PrP. To further contribute to the structural basis for these observations, this paper presents a detailed characterization of RL-PrP(C) conformations in solution. A dynamic local conformational polymorphism involving the β2-α2 loop was found to be evolutionarily preserved among all mammalian species, including those species for which the WT PrP forms an RL-PrP(C). The interconversion between two ensembles of PrP(C) conformers that contain, respectively, a 310-helix turn or a type I β-turn structure of the β2-α2 loop, exposes two different surface epitopes, which are analyzed for their possible roles in the still evasive function of PrP(C) in healthy organisms and/or at the onset of a transmissible spongiform encephalopathy.
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