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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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2
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L P Hosszu L, Sangar D, Batchelor M, Risse E, Hounslow AM, Collinge J, Waltho JP, Bieschke J. Loss of residues 119 - 136, including the first β-strand of human prion protein, generates an aggregation-competent partially "open" form. J Mol Biol 2023:168158. [PMID: 37244570 DOI: 10.1016/j.jmb.2023.168158] [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: 11/18/2022] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/29/2023]
Abstract
In prion replication, the cellular form of prion protein (PrPC) must undergo a full conformational transition to its disease-associated fibrillar form. Transmembrane forms of PrP have been implicated in this structural conversion. The cooperative unfolding of a structural core in PrPC presents a substantial energy barrier to prion formation, with membrane insertion and detachment of parts of PrP presenting a plausible route to its reduction. Here, we examined the removal of residues 119 - 136 of PrP, a region which includes the first β-strand and a substantial portion of the conserved hydrophobic region of PrP, a region which associates with the ER membrane, on the structure, stability and self-association of the folded domain of PrPC. We see an "open" native-like conformer with increased solvent exposure which fibrilises more readily than the native state. These data suggest a stepwise folding transition, which is initiated by the conformational switch to this "open" form of PrPC.
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Affiliation(s)
- Laszlo L P Hosszu
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK
| | - Daljit Sangar
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK
| | - Mark Batchelor
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK
| | - Emmanuel Risse
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK
| | - Andrea M Hounslow
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - John Collinge
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK
| | - Jonathan P Waltho
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK; Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Jan Bieschke
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London, W1W 7FF, UK.
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3
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Rahman A, Saikia B, Gogoi CR, Baruah A. Advances in the understanding of protein misfolding and aggregation through molecular dynamics simulation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 175:31-48. [PMID: 36044970 DOI: 10.1016/j.pbiomolbio.2022.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Aberrant protein folding known as protein misfolding is counted as one of the striking factors of neurodegenerative diseases. The extensive range of pathologies caused by protein misfolding, aggregation and subsequent accumulation are mainly classified into either gain of function diseases or loss of function diseases. In order to seek for novel strategies for treatment and diagnosis of neurodegenerative diseases, insights into the mechanism of misfolding and aggregation is essential. A comprehensive knowledge on the factors influencing misfolding and aggregation is required as well. An extensive experimental study on protein aggregation is somewhat challenging due to the insoluble and noncrystalline nature of amyloid fibrils. Thus there has been a growing use of computational approaches including Monte Carlo simulation, docking simulation, molecular dynamics simulation in the study of protein misfolding and aggregation. The review presents a discussion on molecular dynamics simulation alone as to how it has emerged as a promising tool in the understanding of protein misfolding and aggregation in general, detailing upon three different aspects considering four misfold prone proteins in particular. It is noticeable that all four proteins considered in this review i.e prion, superoxide dismutase1, huntingtin and amyloid β are linked to chronic neurodegenerative diseases with debilitating effects. Initially the review elaborates on the factors influencing the misfolding and aggregation. Next, it addresses our current understanding of the amyloid structures and the associated aggregation mechanisms, finally, summarizing the contribution of this computational tool in the search for therapeutic strategies against the respective protein-deposition diseases.
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Affiliation(s)
- Aziza Rahman
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Bondeepa Saikia
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Chimi Rekha Gogoi
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Anupaul Baruah
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India.
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4
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Adhikari UK, Tayebi M. Epitope-specific anti-PrP antibody toxicity: a comparative in-silico study of human and mouse prion proteins. Prion 2021; 15:155-176. [PMID: 34632945 PMCID: PMC8900626 DOI: 10.1080/19336896.2021.1964326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Despite having therapeutic potential, anti-PrP antibodies caused a major controversy due to their neurotoxic effects. For instance, treating mice with ICSM antibodies delayed prion disease onset, but both were found to be either toxic or innocuous to neurons by researchers following cross-linking PrPC. In order to elucidate and understand the reasons that led to these contradictory outcomes, we conducted a comprehensive in silico study to assess the antibody-specific toxicity. Since most therapeutic anti-PrP antibodies were generated against human truncated recombinant PrP91-231 or full-length mouse PrP23-231, we reasoned that host specificity (human vs murine) of PrPC might influence the nature of the specific epitopes recognized by these antibodies at the structural level possibly explaining the 'toxicity' discrepancies reported previously. Initially, molecular dynamics simulation and pro-motif analysis of full-length human (hu)PrP and mouse (mo)PrP 3D structure displayed conspicuous structural differences between huPrP and moPrP. We identified 10 huPrP and 6 moPrP linear B-cell epitopes from the prion protein 3D structure where 5 out of 10 huPrP and 3 out of 6 moPrP B-cell epitopes were predicted to be potentially toxic in immunoinformatics approaches. Herein, we demonstrate that some of the predicted potentially 'toxic' epitopes identified by the in silico analysis were similar to the epitopes recognized by the toxic antibodies such as ICSM18 (146-159), POM1 (138-147), D18 (133-157), ICSM35 (91-110), D13 (95-103) and POM3 (95-100). This in silico study reveals the role of host specificity of PrPC in epitope-specific anti-PrP antibody toxicity.
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Affiliation(s)
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
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Bergasa-Caceres F, Rabitz HA. Identification of Two Early Folding Stage Prion Non-Local Contacts Suggested to Serve as Key Steps in Directing the Final Fold to Be Either Native or Pathogenic. Int J Mol Sci 2021; 22:ijms22168619. [PMID: 34445324 PMCID: PMC8395309 DOI: 10.3390/ijms22168619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/16/2022] Open
Abstract
The initial steps of the folding pathway of the C-terminal domain of the murine prion protein mPrP(90–231) are predicted based on the sequential collapse model (SCM). A non-local dominant contact is found to form between the connecting region between helix 1 and β-sheet 1 and the C-terminal region of helix 3. This non-local contact nucleates the most populated molten globule-like intermediate along the folding pathway. A less stable early non-local contact between segments 120–124 and 179–183, located in the middle of helix 2, promotes the formation of a less populated molten globule-like intermediate. The formation of the dominant non-local contact constitutes an example of the postulated Nature’s Shortcut to the prion protein collapse into the native structure. The possible role of the less populated molten globule-like intermediate is explored as the potential initiation point for the folding for three pathogenic mutants (T182A, I214V, and Q211P in mouse prion numbering) of the prion protein.
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Lee KH, Kuczera K. Free energy simulations to understand the effect of Met → Ala mutations at positions 205, 206 and 213 on stability of human prion protein. Biophys Chem 2021; 275:106620. [PMID: 34058726 DOI: 10.1016/j.bpc.2021.106620] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 01/23/2023]
Abstract
Prion diseases are a family of infectious amyloid diseases affecting human and animals. Prion propagation in transmissible spongiform encephalopathies is associated with the unfolding and conversion of normal cellular prion protein into its pathogenic scrapie form. Understanding the fundamentals of prion protein aggregation caused by mutations is crucial to unravel the pathology of prion diseases. To help understand the contributions of individual residues to the stability of the human prion protein, we have carried out free energy simulations based on atomistic molecular dynamics trajectories. We focus on Met → Ala mutations at positions 205, 206 and 213, which are mostly buried residues located on helix 3 of the protein. The simulations predicted that all three mutations destabilize the prion protein. Changes in unfolding free energy upon mutation, ∆∆G, are 3.10 ± 0.79, 2.00 ± 0.26 and 3.06 ± 0.66 kcal/mol for M205A, M206A and M213A, respectively, in excellent agreement with the corresponding experimental values of 3.09 ± 0.28, 1.50 ± 0.34 and 3.12 ± 0.27 kcal/mol [T. Hart et al. (2009) PNAS 106, 5651-5656]. Component analysis indicates that the major contributions to the loss of protein stability arise from van der Waals interactions for the M205A and M206A mutations, and from van der Waals and covalent energy terms for M213A. Interestingly, while free energy contributions from a majority of residues neighboring the mutation sites tend to stabilize the wild type, there are a few residues stabilizing the mutant side chains. Our results show that this approach to free energy calculation can be very useful for understanding the detailed mechanism of human prion protein stability.
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Affiliation(s)
- Kyung-Hoon Lee
- Department of Biology, Chowan University, One University Drive, Murfreesboro, NC 27855, United States of America.
| | - Krzysztof Kuczera
- Department of Chemistry and Department of Molecular Biosciences, University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, United States of America
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Bistaffa E, Marín-Moreno A, Espinosa JC, De Luca CMG, Cazzaniga FA, Portaleone SM, Celauro L, Legname G, Giaccone G, Torres JM, Moda F. PMCA-generated prions from the olfactory mucosa of patients with Fatal Familial Insomnia cause prion disease in mice. eLife 2021; 10:65311. [PMID: 33851575 PMCID: PMC8064759 DOI: 10.7554/elife.65311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/13/2021] [Indexed: 11/24/2022] Open
Abstract
Background: Fatal Familial Insomnia (FFI) is a genetic prion disease caused by the D178N mutation in the prion protein gene (PRNP) in coupling phase with methionine at PRNP 129. In 2017, we have shown that the olfactory mucosa (OM) collected from FFI patients contained traces of PrPSc detectable by Protein Misfolding Cyclic Amplification (PMCA). Methods: In this work, we have challenged PMCA-generated products obtained from OM and brain homogenate of FFI patients in BvPrP-Tg407 transgenic mice expressing the bank vole prion protein to test their ability to induce prion pathology. Results: All inoculated mice developed mild spongiform changes, astroglial activation, and PrPSc deposition mainly affecting the thalamus. However, their neuropathological alterations were different from those found in the brain of BvPrP-Tg407 mice injected with raw FFI brain homogenate. Conclusions: Although with some experimental constraints, we show that PrPSc present in OM of FFI patients is potentially infectious. Funding: This work was supported in part by the Italian Ministry of Health (GR-2013-02355724 and Ricerca Corrente), MJFF, ALZ, Alzheimer’s Research UK and the Weston Brain Institute (BAND2015), and Euronanomed III (SPEEDY) to FM; by the Spanish Ministerio de Economía y Competitividad (grant AGL2016-78054-R [AEI/FEDER, UE]) to JMT and JCE; AM-M was supported by a fellowship from the INIA (FPI-SGIT-2015-02).
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Affiliation(s)
- Edoardo Bistaffa
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milan, Italy
| | - Alba Marín-Moreno
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Juan Carlos Espinosa
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Chiara Maria Giulia De Luca
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milan, Italy.,Scuola Internazionale Superiore di Studi Avanzati (SISSA), Department of Neuroscience, Laboratory of Prion Biology, Trieste, Italy
| | - Federico Angelo Cazzaniga
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milan, Italy
| | - Sara Maria Portaleone
- ASST Santi Paolo e Carlo, Department of Health Sciences, Otolaryngology Unit, Università Degli Studi di Milano, Milan, Italy
| | - Luigi Celauro
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Department of Neuroscience, Laboratory of Prion Biology, Trieste, Italy
| | - Giuseppe Legname
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Department of Neuroscience, Laboratory of Prion Biology, Trieste, Italy
| | - Giorgio Giaccone
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milan, Italy
| | - Juan Maria Torres
- Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain
| | - Fabio Moda
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milan, Italy
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Sanz-Hernández M, De Simone A. Backbone NMR assignments of the C-terminal domain of the human prion protein and its disease-associated T183A variant. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:193-196. [PMID: 33590433 PMCID: PMC7974147 DOI: 10.1007/s12104-021-10005-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative disorders associated with the misfolding and aggregation of the human prion protein (huPrP). Despite efforts into investigating the process of huPrP aggregation, the mechanisms triggering its misfolding remain elusive. A number of TSE-associated mutations of huPrP have been identified, but their role at the onset and progression of prion diseases is unclear. Here we report the NMR assignments of the C-terminal globular domain of the wild type huPrP and the pathological mutant T183A. The differences in chemical shifts between the two variants reveal conformational alterations in some structural elements of the mutant, whereas the analyses of secondary shifts and random coil index provide indications on the putative mechanisms of misfolding of T183A huPrP.
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Affiliation(s)
- Máximo Sanz-Hernández
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Alfonso De Simone
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK.
- Department of Pharmacy, University of Naples "Federico II", 80131, Naples, Italy.
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Mechanism of misfolding of the human prion protein revealed by a pathological mutation. Proc Natl Acad Sci U S A 2021; 118:2019631118. [PMID: 33731477 PMCID: PMC7999870 DOI: 10.1073/pnas.2019631118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The misfolding and aggregation of the human prion protein (PrP) is associated with transmissible spongiform encephalopathies (TSEs). Intermediate conformations forming during the conversion of the cellular form of PrP into its pathological scrapie conformation are key drivers of the misfolding process. Here, we analyzed the properties of the C-terminal domain of the human PrP (huPrP) and its T183A variant, which is associated with familial forms of TSEs. We show that the mutation significantly enhances the aggregation propensity of huPrP, such as to uniquely induce amyloid formation under physiological conditions by the sole C-terminal domain of the protein. Using NMR spectroscopy, biophysics, and metadynamics simulations, we identified the structural characteristics of the misfolded intermediate promoting the aggregation of T183A huPrP and the nature of the interactions that prevent this species to be populated in the wild-type protein. In support of these conclusions, POM antibodies targeting the regions that promote PrP misfolding were shown to potently suppress the aggregation of this amyloidogenic mutant.
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10
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Bettinger J, Ghaemmaghami S. Methionine oxidation within the prion protein. Prion 2020; 14:193-205. [PMID: 32744136 PMCID: PMC7518762 DOI: 10.1080/19336896.2020.1796898] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/09/2020] [Accepted: 07/11/2020] [Indexed: 11/01/2022] Open
Abstract
Prion diseases are characterized by the self-templated misfolding of the cellular prion protein (PrPC) into infectious aggregates (PrPSc). The detailed molecular basis of the misfolding and aggregation of PrPC remains incompletely understood. It is believed that the transient misfolding of PrPC into partially structured intermediates precedes the formation of insoluble protein aggregates and is a critical component of the prion misfolding pathway. A number of environmental factors have been shown to induce the destabilization of PrPC and promote its initial misfolding. Recently, oxidative stress and reactive oxygen species (ROS) have emerged as one possible mechanism by which the destabilization of PrPC can be induced under physiological conditions. Methionine residues are uniquely vulnerable to oxidation by ROS and the formation of methionine sulfoxides leads to the misfolding and subsequent aggregation of PrPC. Here, we provide a review of the evidence for the oxidation of methionine residues in PrPC and its potential role in the formation of pathogenic prion aggregates.
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Affiliation(s)
- John Bettinger
- Department of Biology, University of Rochester, Rochester, NY, USA
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11
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Suzuki A, Sawada K, Yamasaki T, Denkers ND, Mathiason CK, Hoover EA, Horiuchi M. Involvement of N- and C-terminal region of recombinant cervid prion protein in its reactivity to CWD and atypical BSE prions in real-time quaking-induced conversion reaction in the presence of high concentrations of tissue homogenates. Prion 2020; 14:283-295. [PMID: 33345717 PMCID: PMC7757825 DOI: 10.1080/19336896.2020.1858694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 11/17/2022] Open
Abstract
The real-time quaking-induced conversion (RT-QuIC) reaction is a sensitive and specific method for detecting prions. However, inhibitory factors present in tissue homogenates can easily interfere with this reaction. To identify the RT-QuIC condition under which low levels of chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions can be detected in the presence of high concentrations of brain tissue homogenates, reactivities of various recombinant prion proteins (rPrPs) were tested. Among the tested rPrPs, recombinant cervid PrP (rCerPrP) showed a unique reactivity: the reactivity of rCerPrP to CWD and atypical BSE prions was not highly affected by high concentrations of normal brain homogenates. The unique reactivity of rCerPrP disappeared when the N-terminal region (aa 25-93) was truncated. Replacement of aa 23-149 of mouse (Mo) PrP with the corresponding region of CerPrP partially restored the unique reactivity of rCerPrP in RT-QuIC. Replacement of the extreme C-terminal region of MoPrP aa 219-231 to the corresponding region of CerPrP partially conferred the unique reactivity of rCerPrP to rMoPrP, suggesting the involvement of both N- and C-terminal regions. Additionally, rCerN-Mo-CerCPrP, a chimeric PrP comprising CerPrP aa 25-153, MoPrP aa 150-218, and CerPrP aa 223-233, showed an additive effect of the N- and C-terminal regions. These results provide a mechanistic implication for detecting CWD and atypical BSE prions using rCerPrP and are useful for further improvements of RT-QuIC.
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Affiliation(s)
- Akio Suzuki
- Laboratory of Veterinary Hygiene, Graduate School of Infectious Diseases, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Kazuhei Sawada
- Laboratory of Veterinary Hygiene, Graduate School of Infectious Diseases, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Graduate School of Infectious Diseases, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Nathaniel D Denkers
- Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Candace K Mathiason
- Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Edward A Hoover
- Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Graduate School of Infectious Diseases, Hokkaido University, Kita-ku, Sapporo, Japan
- Global Station for Zoonosis Control. Global Institute for Collaborative Research and Education, Hokkaido University, Kita-ku, Sapporo, Japan
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12
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Zhang M, Zhang H, Yao H, Guo C, Lin D. Biophysical characterization of oligomerization and fibrillization of the G131V pathogenic mutant of human prion protein. Acta Biochim Biophys Sin (Shanghai) 2019; 51:1223-1232. [PMID: 31735962 DOI: 10.1093/abbs/gmz124] [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: 05/13/2019] [Indexed: 11/14/2022] Open
Abstract
The pathogenesis of fatal neurodegenerative prion diseases is closely associated with the conversion of α-helix-rich cellular prion protein into β-sheet-rich scrapie form. Pathogenic point mutations of prion proteins usually promote the conformational conversion and trigger inherited prion diseases. The G131V mutation of human prion protein (HuPrP) was identified to be involved in Gerstmann-Sträussler-Scheinker syndrome. Few studies have been carried out to address the pathogenesis of the G131V mutant. Here, we addressed the effects of the G131V mutation on oligomerization and fibrillization of the full-length HuPrP(23-231) and truncated HuPrP(91-231) proteins. The G131V mutation promotes the oligomerization but alleviates the fibrillization of HuPrP, implying that the oligomerization might play a crucial role in the pathogenic mechanisms of the G131V mutant. Moreover, the flexible N-terminal fragment in either the wild-type or the G131V mutant HuPrP increases the oligomerization tendencies but decreases the fibrillization tendencies. Furthermore, this mutation significantly alters the tertiary structure of human PrPC and might distinctly change the conformational conversion tendency. Interestingly, both guanidine hydrochloride denaturation and thermal denaturation experiments showed that the G131V mutation does not significantly change the thermodynamic stabilities of the HuPrP proteins. This work may be of benefit to a mechanistic understanding of the conformational conversion of prion proteins and also provide clues for the prevention and treatment of prion diseases.
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Affiliation(s)
- Meilan Zhang
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Haoran Zhang
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Hongwei Yao
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Chenyun Guo
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Donghai Lin
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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Fuller DR, Conant CR, El-Baba TJ, Zhang Z, Molloy KR, Zhang CS, Hales DA, Clemmer DE. Monitoring the stabilities of a mixture of peptides by mass-spectrometry-based techniques. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2019; 25:73-81. [PMID: 30773926 PMCID: PMC7702224 DOI: 10.1177/1469066718798718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Biomolecular degradation plays a key role in proteostasis. Typically, proteolytic enzymes degrade proteins into smaller peptides by breaking amino acid bonds between specific residues. Cleavage around proline residues is often missed and requires highly specific enzymes for peptide processing due to the cyclic proline side-chain. However, degradation can occur spontaneously (i.e. in the absence of enzymes). In this study, the influence of the first residue on the stability of a series of penultimate proline containing peptides, with the sequence Xaa-Pro-Gly-Gly (where Xaa is any amino acid), is investigated with mass spectrometry techniques. Peptides were incubated as mixtures at various solution temperatures (70℃ to 90℃) and were periodically sampled over the duration of the experiment. At elevated temperatures, we observe dissociation after the Xaa-Pro motif for all sequences, but at different rates. Transition state thermochemistry was obtained by studying the temperature-dependent kinetics and although all peptides show relatively small differences in the transition state free energies (∼95 kJ/mol), there is significant variability in the transition state entropy and enthalpy. This demonstrates that the side-chain of the first amino acid has a significant influence on the stability of the Xaa-Pro sequence. From these data, we demonstrate the ability to simultaneously measure the dissociation kinetics and relative transition state thermochemistries for a mixture of peptides, which vary only in the identity of the N-terminal amino acid.
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Affiliation(s)
- Daniel R Fuller
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | | | - Tarick J El-Baba
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Zhichao Zhang
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | | | - Connie S Zhang
- Department of Chemistry, Hendrix College, Conway, AR, USA
| | - David A Hales
- Department of Chemistry, Hendrix College, Conway, AR, USA
| | - David E Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN, USA
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14
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Markham KA, Roseman GP, Linsley RB, Lee HW, Millhauser GL. Molecular Features of the Zn 2+ Binding Site in the Prion Protein Probed by 113Cd NMR. Biophys J 2019; 116:610-620. [PMID: 30678993 DOI: 10.1016/j.bpj.2019.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 10/27/2022] Open
Abstract
The cellular prion protein (PrPC) is a zinc-binding protein that contributes to the regulation of Zn2+ and other divalent species of the central nervous system. Zn2+ coordinates to the flexible, N-terminal repeat region of PrPC and drives a tertiary contact between this repeat region and a well-defined cleft of the C-terminal domain. The tertiary structure promoted by Zn2+ is thought to regulate inherent PrPC toxicity. Despite the emerging consensus regarding the interaction between Zn2+ and PrPC, there is little direct spectroscopic confirmation of the metal ion's coordination details. Here, we address this conceptual gap by using Cd2+ as a surrogate for Zn2+. NMR finds that Cd2+ binds exclusively to the His imidazole side chains of the repeat segment, with a dissociation constant of ∼1.2 mM, and promotes an N-terminal-C-terminal cis interaction very similar to that observed with Zn2+. Analysis of 113Cd NMR spectra of PrPC, along with relevant control proteins and peptides, suggests that coordination of Cd2+ in the full-length protein is consistent with a three- or four-His geometry. Examination of the mutation E199K in mouse PrPC (E200K in humans), responsible for inherited Creutzfeldt-Jakob disease, finds that the mutation lowers metal ion affinity and weakens the cis interaction. These findings not only provide deeper insight into PrPC metal ion coordination but they also suggest new perspectives on the role of familial mutations in prion disease.
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Affiliation(s)
- Kate A Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Graham P Roseman
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Richard B Linsley
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California.
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15
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Structural Determinants of the Prion Protein N-Terminus and Its Adducts with Copper Ions. Int J Mol Sci 2018; 20:ijms20010018. [PMID: 30577569 PMCID: PMC6337743 DOI: 10.3390/ijms20010018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/24/2022] Open
Abstract
The N-terminus of the prion protein is a large intrinsically disordered region encompassing approximately 125 amino acids. In this paper, we review its structural and functional properties, with a particular emphasis on its binding to copper ions. The latter is exploited by the region’s conformational flexibility to yield a variety of biological functions. Disease-linked mutations and proteolytic processing of the protein can impact its copper-binding properties, with important structural and functional implications, both in health and disease progression.
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16
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Mok TH, Koriath C, Jaunmuktane Z, Campbell T, Joiner S, Wadsworth JDF, Hosszu LLP, Brandner S, Parvez A, Truelsen TC, Lund EL, Saha R, Collinge J, Mead S. Evaluating the causality of novel sequence variants in the prion protein gene by example. Neurobiol Aging 2018; 71:265.e1-265.e7. [PMID: 29861043 PMCID: PMC6175539 DOI: 10.1016/j.neurobiolaging.2018.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/22/2018] [Accepted: 05/06/2018] [Indexed: 11/13/2022]
Abstract
The estimation of pathogenicity and penetrance of novel prion protein gene (PRNP) variants presents significant challenges, particularly in the absence of family history, which precludes the application of Mendelian segregation. Moreover, the ambiguities of prion disease pathophysiology renders conventional in silico predictions inconclusive. Here, we describe 2 patients with rapid cognitive decline progressing to akinetic mutism and death within 10 weeks of symptom onset, both of whom possessed the novel T201S variant in PRNP. Clinically, both satisfied diagnostic criteria for probable sporadic Creutzfeldt-Jakob disease and in one, the diagnosis was confirmed by neuropathology. While computational analyses predicted that T201S was possibly deleterious, molecular strain typing, prion protein structural considerations, and calculations leveraging large-scale population data (gnomAD) indicate that T201S is at best either of low penetrance or nonpathogenic. Thus, we illustrate the utility of harnessing multiple lines of prion disease-specific evidence in the evaluation of the T201S variant, which may be similarly applied to assess other novel variants in PRNP.
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Affiliation(s)
- Tze How Mok
- MRC Prion Unit, UCL Institute of Prion Diseases, London, UK; National Prion Clinic, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Carolin Koriath
- Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK
| | - Zane Jaunmuktane
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK; Division of Neuropathology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Tracy Campbell
- MRC Prion Unit, UCL Institute of Prion Diseases, London, UK
| | - Susan Joiner
- MRC Prion Unit, UCL Institute of Prion Diseases, London, UK
| | | | | | - Sebastian Brandner
- Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK; Division of Neuropathology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Ambereen Parvez
- Department of Neurology, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | | | - Eva Løbner Lund
- Department of Pathology, Rigshospitalet, Copenhagen, Denmark
| | - Romi Saha
- Hurstwood Park Neurological Centre, Sussex, UK
| | - John Collinge
- MRC Prion Unit, UCL Institute of Prion Diseases, London, UK; National Prion Clinic, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Simon Mead
- MRC Prion Unit, UCL Institute of Prion Diseases, London, UK; National Prion Clinic, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK.
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17
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Kakuda K, Yamaguchi KI, Kuwata K, Honda R. A valine-to-lysine substitution at position 210 induces structural conversion of prion protein into a β-sheet rich oligomer. Biochem Biophys Res Commun 2018; 506:81-86. [PMID: 30336980 DOI: 10.1016/j.bbrc.2018.10.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 10/12/2018] [Indexed: 12/18/2022]
Abstract
Prion diseases are fatal neurodegenerative diseases associated with structural conversion of α-helical prion protein (PrP) into its β-sheet rich isoform (PrPSc). Previous genetic analyses have indicated that several amino acid residues involved in the hydrophobic core of PrP (such as V180, F198, and V210) play a critical role in the development of prion diseases. To understand how these hydrophobic residues would contribute to the α-to-β conversion process of PrP, we substituted the V210 residue with bulkier (V210F, V210I, and V210L), smaller (V210A), and charged amino acids (V210K) and characterized its effects. Interestingly, although most of the mutations had little or no effect on the biochemical properties of PrP, the V210K mutation induced structural conversion of PrP into a β-structure. The β-inducing effect was prominent and observed even under a physiological condition (i.e., in the absence of denaturant, acidic pH, reducing agent, and high temperature) in contrast to the disease-associated mutations in the PrP gene. We also examined structural features of V210K PrP using guanidine-hydrochloride unfolding, dynamic light scattering, 8-anilino-1-naphthalene sulfonate fluorescence, and electron microscopy, and revealed that V210K PrP assembles into a non-fibrillar β-rich oligomer. Thus, the α-to-β conversion can be induced by introduction of a charged residue into the hydrophobic core, which provide novel insight into the structural dynamics of PrP.
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Affiliation(s)
- Kyosuke Kakuda
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, 501-1193, Japan
| | - Kei-Ichi Yamaguchi
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka, 565-0871, Japan
| | - Kazuo Kuwata
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, 501-1193, Japan; Department of Gene and Development, Graduate School of Medicine, Gifu University, Gifu, 501-1193, Japan
| | - Ryo Honda
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, 501-1193, Japan.
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18
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Sengupta I, Udgaonkar JB. Structural mechanisms of oligomer and amyloid fibril formation by the prion protein. Chem Commun (Camb) 2018; 54:6230-6242. [PMID: 29789820 DOI: 10.1039/c8cc03053g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Misfolding and aggregation of the prion protein is responsible for multiple neurodegenerative diseases. Works from several laboratories on folding of both the WT and multiple pathogenic mutant variants of the prion protein have identified several structurally dissimilar intermediates, which might be potential precursors to misfolding and aggregation. The misfolded aggregates themselves are morphologically distinct, critically dependent on the solution conditions under which they are prepared, but always β-sheet rich. Despite the lack of an atomic resolution structure of the infectious pathogenic agent in prion diseases, several low resolution models have identified the β-sheet rich core of the aggregates formed in vitro, to lie in the α2-α3 subdomain of the prion protein, albeit with local stabilities that vary with the type of aggregate. This feature article describes recent advances in the investigation of in vitro prion protein aggregation using multiple spectroscopic probes, with particular focus on (1) identifying aggregation-prone conformations of the monomeric protein, (2) conditions which trigger misfolding and oligomerization, (3) the mechanism of misfolding and aggregation, and (4) the structure of the misfolded intermediates and final aggregates.
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Affiliation(s)
- Ishita Sengupta
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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19
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Mechanism of aggregation and membrane interactions of mammalian prion protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.02.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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20
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Sangeetham SB, Huszár K, Bencsura P, Nyeste A, Hunyadi-Gulyás É, Fodor E, Welker E. Interrogating the Dimerization Interface of the Prion Protein Via Site-Specific Mutations to p-Benzoyl-L-Phenylalanine. J Mol Biol 2018; 430:2784-2801. [PMID: 29778603 DOI: 10.1016/j.jmb.2018.05.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/07/2018] [Accepted: 05/14/2018] [Indexed: 01/10/2023]
Abstract
Transmissible spongiform encephalopathies are centered on the conformational transition of the prion protein from a mainly helical, monomeric structure to a β-sheet rich ordered aggregate. Experiments indicate that the main infectious and toxic species in this process are however shorter oligomers, formation of which from the monomers is yet enigmatic. Here, we created 25 variants of the mouse prion protein site-specifically containing one genetically-incorporated para-benzoyl-phenylalanine (pBpa), a cross-linkable non-natural amino acid, in order to interrogate the interface of a prion protein-dimer, which might lie on the pathway of oligomerization. Our results reveal that the N-terminal part of the prion protein, especially regions around position 127 and 107, is integral part of the dimer interface. These together with additional pBpa-containing variants of mPrP might also facilitate to gain more structural insights into oligomeric and fibrillar prion protein species including the pathological variants.
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Affiliation(s)
- Sudheer Babu Sangeetham
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Krisztina Huszár
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Petra Bencsura
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Antal Nyeste
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary; ProteoScientia Ltd., Cserhátszentiván, Hungary
| | - Éva Hunyadi-Gulyás
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Elfrieda Fodor
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ervin Welker
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary; Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
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21
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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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22
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A Sequence-Dependent DNA Condensation Induced by Prion Protein. J Nucleic Acids 2018; 2018:9581021. [PMID: 29657864 PMCID: PMC5838432 DOI: 10.1155/2018/9581021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/18/2017] [Accepted: 01/17/2018] [Indexed: 12/14/2022] Open
Abstract
Different studies indicated that the prion protein induces hybridization of complementary DNA strands. Cell culture studies showed that the scrapie isoform of prion protein remained bound with the chromosome. In present work, we used an oxazole dye, YOYO, as a reporter to quantitative characterization of the DNA condensation by prion protein. We observe that the prion protein induces greater fluorescence quenching of YOYO intercalated in DNA containing only GC bases compared to the DNA containing four bases whereas the effect of dye bound to DNA containing only AT bases is marginal. DNA-condensing biological polyamines are less effective than prion protein in quenching of DNA-bound YOYO fluorescence. The prion protein induces marginal quenching of fluorescence of the dye bound to oligonucleotides, which are resistant to condensation. The ultrastructural studies with electron microscope also validate the biophysical data. The GC bases of the target DNA are probably responsible for increased condensation in the presence of prion protein. To our knowledge, this is the first report of a human cellular protein inducing a sequence-dependent DNA condensation. The increased condensation of GC-rich DNA by prion protein may suggest a biological function of the prion protein and a role in its pathogenesis.
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23
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Sabareesan AT, Udgaonkar JB. The G126V Mutation in the Mouse Prion Protein Hinders Nucleation-Dependent Fibril Formation by Slowing Initial Fibril Growth and by Increasing the Critical Concentration. Biochemistry 2017; 56:5931-5942. [PMID: 29045139 DOI: 10.1021/acs.biochem.7b00894] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The middle disordered hydrophobic region of the prion protein plays a critical role in conformational conversion of the protein, with pathogenic as well as protective mutations being localized to this region. In particular, it has been shown that the G127V mutation in this region of the human prion protein (huPrP) is protective against the spread of prion disease, but the mechanism of protection remains unknown. In this study, quantitative analyses of the kinetics of fibril formation by wild-type mouse prion protein (moPrP) and G126V moPrP (equivalent to G127V huPrP) reveal important differences: the critical concentration is higher, the lag phase is longer, and the initial effective rate constant of fibril growth is slower for the mutant variant. The study offers a simple biophysical explanation for why the G127V mutation in huPrP would be protective in humans: the ∼5-fold increase in critical concentration caused by the mutation likely results in the critical concentration (below which fibril formation cannot occur) being higher that the concentration of the protein present in and on cells in vivo.
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Affiliation(s)
- Ambadi Thody Sabareesan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research , Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research , Bengaluru 560065, India
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24
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Genetic human prion disease modelled in PrP transgenic Drosophila. Biochem J 2017; 474:3253-3267. [PMID: 28814578 PMCID: PMC5606059 DOI: 10.1042/bcj20170462] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/07/2017] [Accepted: 08/15/2017] [Indexed: 12/26/2022]
Abstract
Inherited human prion diseases, such as fatal familial insomnia (FFI) and familial Creutzfeldt–Jakob disease (fCJD), are associated with autosomal dominant mutations in the human prion protein gene PRNP and accumulation of PrPSc, an abnormal isomer of the normal host protein PrPC, in the brain of affected individuals. PrPSc is the principal component of the transmissible neurotoxic prion agent. It is important to identify molecular pathways and cellular processes that regulate prion formation and prion-induced neurotoxicity. This will allow identification of possible therapeutic interventions for individuals with, or at risk from, genetic human prion disease. Increasingly, Drosophila has been used to model human neurodegenerative disease. An important unanswered question is whether genetic prion disease with concomitant spontaneous prion formation can be modelled in Drosophila. We have used pUAST/PhiC31-mediated site-directed mutagenesis to generate Drosophila transgenic for murine or hamster PrP (prion protein) that carry single-codon mutations associated with genetic human prion disease. Mouse or hamster PrP harbouring an FFI (D178N) or fCJD (E200K) mutation showed mild Proteinase K resistance when expressed in Drosophila. Adult Drosophila transgenic for FFI or fCJD variants of mouse or hamster PrP displayed a spontaneous decline in locomotor ability that increased in severity as the flies aged. Significantly, this mutant PrP-mediated neurotoxic fly phenotype was transferable to recipient Drosophila that expressed the wild-type form of the transgene. Collectively, our novel data are indicative of the spontaneous formation of a PrP-dependent neurotoxic phenotype in FFI- or CJD-PrP transgenic Drosophila and show that inherited human prion disease can be modelled in this invertebrate host.
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25
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Copper- and Zinc-Promoted Interdomain Structure in the Prion Protein: A Mechanism for Autoinhibition of the Neurotoxic N-Terminus. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:35-56. [PMID: 28838668 DOI: 10.1016/bs.pmbts.2017.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The function of the cellular prion protein (PrPC), while still poorly understood, is increasingly linked to its ability to bind physiological metal ions at the cell surface. PrPC binds divalent forms of both copper and zinc through its unstructured N-terminal domain, modulating interactions between PrPC and various receptors at the cell surface and ultimately tuning downstream cellular processes. In this chapter, we briefly discuss the molecular features of copper and zinc uptake by PrPC and summarize evidence implicating these metal ions in PrP-mediated physiology. We then focus our review on recent biophysical evidence revealing a physical interaction between the flexible N-terminal and globular C-terminal domains of PrPC. This interdomain cis interaction is electrostatic in nature and is promoted by the binding of Cu2+ and Zn2+ to the N-terminal octarepeat domain. These findings, along with recent cellular studies, suggest a mechanism whereby NC interactions serve to regulate the activity and/or toxicity of the PrPC N-terminus. We discuss this potential mechanism in relation to familial prion disease mutations, lethal deletions of the PrPC central region, and neurotoxicity induced by certain globular domain ligands, including bona fide prions and toxic amyloid-β oligomers.
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26
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Redaelli V, Tagliavini F, Moda F. Clinical features, pathophysiology and management of fatal familial insomnia. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1311251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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27
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Steinbrecher T, Zhu C, Wang L, Abel R, Negron C, Pearlman D, Feyfant E, Duan J, Sherman W. Predicting the Effect of Amino Acid Single-Point Mutations on Protein Stability—Large-Scale Validation of MD-Based Relative Free Energy Calculations. J Mol Biol 2017; 429:948-963. [DOI: 10.1016/j.jmb.2016.12.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 12/22/2022]
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28
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Steinbrecher T, Abel R, Clark A, Friesner R. Free Energy Perturbation Calculations of the Thermodynamics of Protein Side-Chain Mutations. J Mol Biol 2017; 429:923-929. [DOI: 10.1016/j.jmb.2017.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 01/20/2023]
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29
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Moulick R, Udgaonkar JB. Identification and Structural Characterization of the Precursor Conformation of the Prion Protein which Directly Initiates Misfolding and Oligomerization. J Mol Biol 2017; 429:886-899. [DOI: 10.1016/j.jmb.2017.01.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 12/11/2022]
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30
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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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31
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Biljan I, Ilc G, Plavec J. Analysis of Prion Protein Structure Using Nuclear Magnetic Resonance Spectroscopy. Methods Mol Biol 2017; 1658:35-49. [PMID: 28861781 DOI: 10.1007/978-1-4939-7244-9_4] [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: 01/19/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful experimental tool for obtaining information on three-dimensional (3D) structures of proteins at atomic resolution. In inherited forms of prion diseases, misfolding of cellular prion protein, PrPC, into its pathological form, PrPSc, is caused by mutations in the human prion protein gene (PRNP). Understanding of the earliest stages of the conformational changes leading to spontaneous generation of prions in inherited forms of prion diseases may benefit from detailed structural analysis of different human (Hu) PrP variants. Here, we describe the protocol for structure determination of HuPrP variants by NMR spectroscopy in solution that consists of preparation of NMR samples, acquisition of NMR data, NMR resonance assignments, and structure calculation.
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Affiliation(s)
- Ivana Biljan
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102A, 10000, Zagreb, Croatia
| | - Gregor Ilc
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.,EN-FIST Center of Excellence, Trg OF 13, 1000, Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia. .,EN-FIST Center of Excellence, Trg OF 13, 1000, Ljubljana, Slovenia. .,Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000, Ljubljana, Slovenia.
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Understanding the Effect of Disease-Related Mutations on Human Prion Protein Structure: Insights From NMR Spectroscopy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:83-103. [DOI: 10.1016/bs.pmbts.2017.06.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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33
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Structural Modeling of Human Prion Protein's Point Mutations. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:105-122. [DOI: 10.1016/bs.pmbts.2017.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Roberts JH, Liu F, Karnuta JM, Fitzgerald MC. Discovery of Age-Related Protein Folding Stability Differences in the Mouse Brain Proteome. J Proteome Res 2016; 15:4731-4741. [PMID: 27806573 DOI: 10.1021/acs.jproteome.6b00927] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Described here is the application of thermodynamic stability measurements to study age-related differences in the folding and stability of proteins in a rodent model of aging. Thermodynamic stability profiles were generated for 809 proteins in brain cell lysates from mice, aged 6 (n = 7) and 18 months (n = 9) using the Stability of Proteins from Rates of Oxidation (SPROX) technique. The biological variability of the protein stability measurements was low and within the experimental error of SPROX. A total of 83 protein hits were detected with age-related stability differences in the brain samples. Remarkably, the large majority of the brain protein hits were destabilized in the old mice, and the hits were enriched in proteins that have slow turnover rates (p < 0.07). Furthermore, 70% of the hits have been previously linked to aging or age-related diseases. These results help validate the use of thermodynamic stability measurements to capture relevant age-related proteomic changes and establish a new biophysical link between these proteins and aging.
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Affiliation(s)
- Julia H Roberts
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Fang Liu
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Jaret M Karnuta
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Michael C Fitzgerald
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
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Kovač V, Hafner-Bratkovič I, Čurin Šerbec V. Anchorless forms of prion protein - Impact of truncation on structure destabilization and prion protein conversion. Biochem Biophys Res Commun 2016; 481:1-6. [PMID: 27836542 DOI: 10.1016/j.bbrc.2016.11.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 11/07/2016] [Indexed: 10/20/2022]
Abstract
Prion diseases are a group of fatal neurodegenerative diseases caused by scrapie form of prion protein, PrPSc. Prion protein (PrP) is bound to the cell via glycophosphatidylinositol (GPI) anchor. The role of GPI anchor in PrPSc replication and propagation remains unclear. It has been shown that anchorless and truncated PrP accelerate the formation and propagation of prions in vivo and further increases the risk for transmission of prion diseases among species. To explain the role of anchorless forms of PrP in the development of prion diseases, we have prepared five C-terminal PrP truncated variants, determined their thermodynamic properties and analyzed the kinetics of conversion into amyloid fibrils. According to our results thermodynamic and kinetic properties are affected both by pH and truncation. We have shown that the shortest variant was the most destabilized and converted faster than other variants in acidic pH. Other variants converted with longer lag time of fibrillization than WT despite comparable or even decreased stability in acidic pH. Our results indicate that even the change in length for 1 amino acid residue can have a profound effect on in vitro conversion.
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Affiliation(s)
- Valerija Kovač
- Department for the Production of Diagnostic Reagents and Research & R&D Service, Blood Transfusion Centre of Slovenia, Šlajmerjeva 6, SI-1000, Ljubljana, Slovenia
| | - Iva Hafner-Bratkovič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1000, Ljubljana, Slovenia; EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, 1000, Ljubljana, Slovenia
| | - Vladka Čurin Šerbec
- Department for the Production of Diagnostic Reagents and Research & R&D Service, Blood Transfusion Centre of Slovenia, Šlajmerjeva 6, SI-1000, Ljubljana, Slovenia.
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Yu Y, Yu Z, Zheng Z, Wang H, Wu X, Guo C, Lin D. Distinct effects of mutations on biophysical properties of human prion protein monomers and oligomers. Acta Biochim Biophys Sin (Shanghai) 2016; 48:1016-1025. [PMID: 27649893 DOI: 10.1093/abbs/gmw094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/15/2016] [Indexed: 02/05/2023] Open
Abstract
Prion diseases are a group of fatal neurodegenerative illnesses, resulting from the conformational conversion of the cellular prion protein (PrPC) into a misfolded form (PrPSc). The formation of neurotoxic soluble prion protein oligomer (PrPO) is regarded as a key step in the development of prion diseases. About 10%-15% of human prion diseases are caused by mutations in the prion protein gene; however, the underlying molecular mechanisms remain unclear. In the present work, we compared the biophysical properties of wild-type (WT) human prion protein 91-231 (WT HuPrP91-231) and its disease-associated variants (P105L, D178N, V203I, and Q212P) using several biophysical techniques. In comparison with WT HuPrPC, the Q212P and D178N variants possessed greatly increased conversion propensities of PrPC into PrPO, while the V203I variant had dramatically decreased conversion propensity. The P105L variant displayed a similar conversion propensity to WT HuPrPC Guanidine hydrochloride-induced unfolding experiments ranked the thermodynamic stabilities of these proteins as Q212P < D178N < WT ≈ P105L < V203I. It was thus suggested that the conversion propensities of the prion proteins are closely associated with their thermodynamic stabilities. Furthermore, structural comparison illustrated that Q212P, D178N, and V203I variants underwent larger structural changes compared with WT HuPrPC, while the P105L variant adopted a similar structure to the WT HuPrPC The mutation-induced structural perturbations might change the thermodynamic stabilities of the HuPrPC variants, and correspondingly alter the conversion propensities for these prion proteins. Our results extend the mechanistic understanding of prion pathogenesis, and lay the basis for the prevention and treatment of prion diseases.
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Affiliation(s)
- Yuanhui Yu
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Ziyao Yu
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Zhen Zheng
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Huilin Wang
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xueji Wu
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Chenyun Guo
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Donghai Lin
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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Sabareesan AT, Udgaonkar JB. Pathogenic Mutations within the Disordered Palindromic Region of the Prion Protein Induce Structure Therein and Accelerate the Formation of Misfolded Oligomers. J Mol Biol 2016; 428:3935-3947. [PMID: 27545411 DOI: 10.1016/j.jmb.2016.08.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/09/2016] [Accepted: 08/12/2016] [Indexed: 12/11/2022]
Abstract
Little is understood about how the intrinsically disordered N-terminal region (NTR) of the prion protein modulates its misfolding and aggregation, which lead to prion disease. In this study, two pathogenic mutations, G113V and A116V, in the palindromic region of the NTR are shown to have no effect on the structure, stability, or dynamics of native mouse prion protein (moPrP) but nevertheless accelerate misfolding and oligomerization. For wild-type moPrP, misfolding and oligomerization appear to occur concurrently, while for both mutant variants, oligomerization is shown to precede misfolding. Kinetic hydrogen-deuterium exchange-mass spectrometry experiments show that sequence segment 89-132 from the NTR becomes structured, albeit weakly, during the oligomerization of both mutant variants. Importantly, this structure formation occurs prior to structural conversion in the C-terminal domain and appears to be the reason that the formation of misfolded oligomers is accelerated by the pathogenic mutations.
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Affiliation(s)
- A T Sabareesan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.
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Singh J, Udgaonkar JB. Unraveling the Molecular Mechanism of pH-Induced Misfolding and Oligomerization of the Prion Protein. J Mol Biol 2016; 428:1345-1355. [PMID: 26854758 DOI: 10.1016/j.jmb.2016.01.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 12/31/2022]
Abstract
The misfolding of the prion protein (PrP) to aggregated forms is linked to several neurodegenerative diseases. Misfolded oligomeric forms of PrP are associated with neurotoxicity and/or infectivity, but the molecular mechanism by which they form is still poorly understood. A reduction in pH is known to be a key factor that triggers misfolded oligomer formation by PrP, but the residues whose protonation is linked with misfolding remain unidentified. The structural consequences of the protonation of these residues also remain to be determined. In the current study, amino acid residues whose protonation is critical for PrP misfolding and oligomerization have been identified using site-directed mutagenesis and misfolding/oligomerization assays. It is shown that the protonation of either H186 or D201, which mimics the effects of pathogenic mutations (H186R and D201N) at both residue sites, is critically linked to the stability, misfolding and oligomerization of PrP. Hydrogen-deuterium exchange studies coupled with mass spectrometry show that the protonation of either H186 or D201 leads to the same common structural change: increased structural dynamics in helix 1 and that in the loop between helix 1 and β-strand 2. It is shown that the protonation of either of these residues is sufficient for accelerating misfolded oligomer formation, most likely because the protonation of either residue causes the same structural perturbation. Hence, the increased structural dynamics in helix 1 and that in the loop between helix 1 and β-strand 2 appear to play an early critical role in acid-induced misfolding of PrP.
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Affiliation(s)
- Jogender Singh
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.
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Singh J, Udgaonkar JB. The Pathogenic Mutation T182A Converts the Prion Protein into a Molten Globule-like Conformation Whose Misfolding to Oligomers but Not to Fibrils Is Drastically Accelerated. Biochemistry 2016; 55:459-69. [DOI: 10.1021/acs.biochem.5b01266] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Jogender Singh
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B. Udgaonkar
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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Menon S, Sengupta N. Perturbations in inter-domain associations may trigger the onset of pathogenic transformations in PrP(C): insights from atomistic simulations. MOLECULAR BIOSYSTEMS 2016; 11:1443-53. [PMID: 25855580 DOI: 10.1039/c4mb00689e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conversion of the predominantly α-helical cellular prion protein (PrP(C)) to the misfolded β-sheet enriched Scrapie form (PrP(Sc)) is a critical event in prion pathogenesis. However, the conformational triggers that lead to the isoform conversion (PrP(C) to PrP(Sc)) remain obscure, and conjectures about the role of unusually hydrophilic, short helix H1 of the C-terminal globular domain in the transition are varied. Helix H1 is anchored to helix H3 via a few stabilizing polar interactions. We have employed fully atomistic molecular dynamics simulations to study the effects triggered by a minor perturbation in the network of these non-bonded interactions in PrP(C). The elimination of just one of the key H1-H3 hydrogen bonds led to a cascade of conformational changes that are consistent with those observed in partially unfolded intermediates of PrP(C), with pathogenic mutations and in low pH environments. Our analyses reveal that the perturbation results in the enhanced conformational flexibility of the protein. The resultant enhancement in the dynamics leads to overall increased solvent exposure of the hydrophobic core residues and concomitant disruption of the H1-H3 inter-domain salt bridge network. This study lends credence to the hypothesis that perturbing the cooperativity of the stabilizing interactions in the PrP(C) globular domain can critically affect its dynamics and may lead to structural transitions of pathological relevance.
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Affiliation(s)
- Sneha Menon
- Physical Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.
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41
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Martínez J, Sánchez R, Castellanos M, Makarava N, Aguzzi A, Baskakov IV, Gasset M. PrP charge structure encodes interdomain interactions. Sci Rep 2015; 5:13623. [PMID: 26323476 PMCID: PMC4555102 DOI: 10.1038/srep13623] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/31/2015] [Indexed: 11/19/2022] Open
Abstract
Almost all proteins contain charged residues, and their chain distribution is tailored to fulfill essential ionic interactions for folding, binding and catalysis. Among proteins, the hinged two-domain chain of the cellular prion protein (PrPC) exhibits a peculiar charge structure with unclear consequences in its structural malleability. To decipher the charge design role, we generated charge-reverted mutants for each domain and analyzed their effect on conformational and metabolic features. We found that charges contain the information for interdomain interactions. Use of dynamic light scattering and thermal denaturation experiments delineates the compaction of the α-fold by an electrostatic compensation between the polybasic 23–30 region and the α3 electronegative surface. This interaction increases stability and disfavors fibrillation. Independently of this structural effect, the N-terminal electropositive clusters regulate the α-cleavage efficiency. In the fibrillar state, use of circular dichroism, atomic-force and fluorescence microscopies reveal that the N-terminal positive clusters and the α3 electronegative surface dictate the secondary structure, the assembly hierarchy and the growth length of the fibril state. These findings show that the PrP charge structure functions as a code set up to ensure function and reduce pathogenic routes.
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Affiliation(s)
- Javier Martínez
- Instituto Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid 28006, Spain
| | - Rosa Sánchez
- Instituto Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid 28006, Spain
| | - Milagros Castellanos
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain; IMDEA-Nanociencia, Madrid 28049, Spain
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital of Zürich, Zürich 8091, Switzerland
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - María Gasset
- Instituto Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid 28006, Spain
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Moulick R, Das R, Udgaonkar JB. Partially Unfolded Forms of the Prion Protein Populated under Misfolding-promoting Conditions: CHARACTERIZATION BY HYDROGEN EXCHANGE MASS SPECTROMETRY AND NMR. J Biol Chem 2015; 290:25227-40. [PMID: 26306043 DOI: 10.1074/jbc.m115.677575] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 12/16/2022] Open
Abstract
The susceptibility of the cellular prion protein (PrP(C)) to convert to an alternative misfolded conformation (PrP(Sc)), which is the key event in the pathogenesis of prion diseases, is indicative of a conformationally flexible native (N) state. In the present study, hydrogen-deuterium exchange (HDX) in conjunction with mass spectrometry and nuclear magnetic resonance spectroscopy were used for the structural and energetic characterization of the N state of the full-length mouse prion protein, moPrP(23-231), under conditions that favor misfolding. The kinetics of HDX of 34 backbone amide hydrogens in the N state were determined at pH 4. In contrast to the results of previous HDX studies on the human and Syrian hamster prion proteins at a higher pH, various segments of moPrP were found to undergo different extents of subglobal unfolding events at pH 4, a pH at which the protein is known to be primed to misfold to a β-rich conformation. No residual structure around the disulfide bond was observed for the unfolded state at pH 4. The N state of the prion protein was observed to be at equilibrium with at least two partially unfolded forms (PUFs). These PUFs, which are accessed by stochastic fluctuations of the N state, have altered surface area exposure relative to the N state. One of these PUFs resembles a conformation previously implicated to be an initial intermediate in the conversion of monomeric protein into misfolded oligomer at pH 4.
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Affiliation(s)
- Roumita Moulick
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Ranabir Das
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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43
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Singh J, Udgaonkar JB. Molecular Mechanism of the Misfolding and Oligomerization of the Prion Protein: Current Understanding and Its Implications. Biochemistry 2015; 54:4431-42. [PMID: 26171558 DOI: 10.1021/acs.biochem.5b00605] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Prion diseases, also known as transmissible spongiform encephalopathies, make up a group of fatal neurodegenerative disorders linked with the misfolding and aggregation of the prion protein (PrP). Although it is not yet understood how the misfolding of PrP induces neurodegeneration, it is widely accepted that the formation of misfolded prion protein (termed PrP(Sc)) is both the triggering event in the disease and the main component of the infectious agent responsible for disease transmission. Despite the clear involvement of PrP(Sc) in prion diseases, the exact composition of PrP(Sc) is not yet well-known. Recent studies show that misfolded oligomers of PrP could, however, be responsible for neurotoxicity and/or infectivity in the prion diseases. Hence, understanding the molecular mechanism of formation of the misfolded oligomers of PrP is critical for developing an understanding about the prion diseases and for developing anti-prion therapeutics. This review discusses recent advances in understanding the molecular mechanism of misfolded oligomer formation by PrP and its implications for the development of anti-prion therapeutics.
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Affiliation(s)
- Jogender Singh
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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44
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Germershaus O, Nultsch K. Localized, non-viral delivery of nucleic acids: Opportunities, challenges and current strategies. Asian J Pharm Sci 2015. [DOI: 10.1016/j.ajps.2014.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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45
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Singh J, Udgaonkar JB. Structural Effects of Multiple Pathogenic Mutations Suggest a Model for the Initiation of Misfolding of the Prion Protein. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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46
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Singh J, Udgaonkar JB. Structural Effects of Multiple Pathogenic Mutations Suggest a Model for the Initiation of Misfolding of the Prion Protein. Angew Chem Int Ed Engl 2015; 54:7529-33. [DOI: 10.1002/anie.201501011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/17/2015] [Indexed: 12/17/2022]
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47
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Adhikari J, West GM, Fitzgerald MC. Global analysis of protein folding thermodynamics for disease state characterization. J Proteome Res 2015; 14:2287-97. [PMID: 25825992 DOI: 10.1021/acs.jproteome.5b00057] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Current methods for the large-scale characterization of disease states generally rely on the analysis of gene and/or protein expression levels. These existing methods fail to detect proteins with disease-related functions and unaltered expression levels. Here we describe the large-scale use of thermodynamic measurements of protein folding and stability for the characterization of disease states. Using the Stable Isotope Labeling with Amino Acids in Cell Culture and Stability of Proteins from Rates of Oxidation (SILAC-SPROX) technique, we assayed ∼800 proteins for protein folding and stability changes in three different cell culture models of breast cancer including the MCF-10A, MCF-7, and MDA-MB-231 cell lines. The thermodynamic stability profiles generated here created distinct molecular markers to differentiate the three cell lines, and a significant fraction (∼45%) of the differentially stabilized proteins did not have altered expression levels. Thus, the differential thermodynamic profiling strategy reported here created novel molecular signatures of breast cancer and provided additional insight into the molecular basis of the disease. Our results establish the utility of protein folding and stability measurements for the study of disease processes, and they suggest that such measurements may be useful for biomarker discovery in disease.
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Affiliation(s)
- Jagat Adhikari
- #Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27708, United States
| | - Graham M West
- †Department of Mass Spectrometry and Proteomics, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Michael C Fitzgerald
- #Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27708, United States.,∥Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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48
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Cheng CJ, Daggett V. Different misfolding mechanisms converge on common conformational changes: human prion protein pathogenic mutants Y218N and E196K. Prion 2015; 8:125-35. [PMID: 24509603 DOI: 10.4161/pri.27807] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Prion diseases are caused by misfolding and aggregation of the prion protein (PrP). Pathogenic mutations such as Y218N and E196K are known to cause Gerstmann-Sträussler-Scheinker syndrome and Creutzfeldt-Jakob disease, respectively. Here we describe molecular dynamics simulations of these mutant proteins to better characterize the detailed conformational effects of these sequence substitutions. Our results indicate that the mutations disrupt the wild-type native PrP(C) structure and cause misfolding. Y218N reduced hydrophobic packing around the X-loop (residues 165-171), and E196K abolished an important wild-type salt bridge. While differences in the mutation site led PrP mutants to misfold along different pathways, we observed multiple traits of misfolding that were common to both mutants. Common traits of misfolding included: 1) detachment of the short helix (HA) from the PrP core; 2) exposure of side chain F198; and 3) formation of a nonnative strand at the N-terminus. The effect of the E196K mutation directly abolished the wild-type salt bridge E196-R156, which further destabilized the F198 hydrophobic pocket and HA. The Y218N mutation propagated its effect by increasing the HB-HC interhelical angle, which in turn disrupted the packing around F198. Furthermore, a nonnative contact formed between E221 and S132 on the S1-HA loop, which offered a direct mechanism for disrupting the hydrophobic packing between the S1-HA loop and HC. While there were common misfolding features shared between Y218N and E196K, the differences in the orientation of HB and HC and the X-loop conformation might provide a structural basis for identifying different prion strains.
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49
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Noble GP, Walsh DJ, Miller MB, Jackson WS, Supattapone S. Requirements for mutant and wild-type prion protein misfolding in vitro. Biochemistry 2015; 54:1180-7. [PMID: 25584902 DOI: 10.1021/bi501495j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Misfolding of the prion protein (PrP) plays a central role in the pathogenesis of infectious, sporadic, and inherited prion diseases. Here we use a chemically defined prion propagation system to study misfolding of the pathogenic PrP mutant D177N in vitro. This mutation causes PrP to misfold spontaneously in the absence of cofactor molecules in a process dependent on time, temperature, pH, and intermittent sonication. Spontaneously misfolded mutant PrP is able to template its unique conformation onto wild-type PrP substrate in a process that requires a phospholipid activity distinct from that required for the propagation of infectious prions. Similar results were obtained with a second pathogenic PrP mutant, E199K, but not with the polymorphic substitution M128V. Moreover, wild-type PrP inhibits mutant PrP misfolding in a dose-dependent manner, and cofactor molecules can antagonize this effect. These studies suggest that interactions between mutant PrP, wild-type PrP, and other cellular factors may control the rate of PrP misfolding in inherited prion diseases.
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Affiliation(s)
- Geoffrey P Noble
- Department of Biochemistry, The Geisel School of Medicine at Dartmouth , Vail Building Room 311, Hanover, New Hampshire 03755, United States
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Hadži S, Ondračka A, Jerala R, Hafner‐Bratkovič I. Pathological mutations H187R and E196K facilitate subdomain separation and prion protein conversion by destabilization of the native structure. FASEB J 2014; 29:882-93. [DOI: 10.1096/fj.14-255646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- San Hadži
- Department of BiotechnologyNational Institute of ChemistryLjubljanaSlovenia
| | - Andrej Ondračka
- Department of BiotechnologyNational Institute of ChemistryLjubljanaSlovenia
| | - Roman Jerala
- Department of BiotechnologyNational Institute of ChemistryLjubljanaSlovenia
- EN‐FIST Centre of ExcellenceLjubljanaSlovenia
| | - Iva Hafner‐Bratkovič
- Department of BiotechnologyNational Institute of ChemistryLjubljanaSlovenia
- EN‐FIST Centre of ExcellenceLjubljanaSlovenia
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