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Burato A, Legname G. Comparing Prion Proteins Across Species: Is Zebrafish a Useful Model? Mol Neurobiol 2024:10.1007/s12035-024-04324-z. [PMID: 38918277 DOI: 10.1007/s12035-024-04324-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 06/19/2024] [Indexed: 06/27/2024]
Abstract
Despite the considerable body of research dedicated to the field of neurodegeneration, the gap in knowledge on the prion protein and its intricate involvement in brain diseases remains substantial. However, in the past decades, many steps forward have been taken toward a better understanding of the molecular mechanisms underlying both the physiological role of the prion protein and the misfolding event converting it into its pathological counterpart, the prion. This review aims to provide an overview of the main findings regarding this protein, highlighting the advantages of many different animal models that share a conserved amino acid sequence and/or structure with the human prion protein. A particular focus will be given to the species Danio rerio, a compelling research organism for the investigation of prion biology, thanks to its conserved orthologs, ease of genetic manipulation, and cost-effectiveness of high-throughput experimentation. We will explore its potential in filling some of the gaps on physiological and pathological aspects of the prion protein, with the aim of directing the future development of therapeutic interventions.
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Affiliation(s)
- Anna Burato
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy.
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2
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Benarroch E. What Are the Roles of Cellular Prion Protein in Normal and Pathologic Conditions? Neurology 2024; 102:e209272. [PMID: 38484222 DOI: 10.1212/wnl.0000000000209272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 03/19/2024] Open
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3
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Shoup D, Priola SA. Full-length prion protein incorporated into prion aggregates is a marker for prion strain-specific destabilization of aggregate structure following cellular uptake. J Biochem 2023; 174:165-181. [PMID: 37099550 PMCID: PMC10506170 DOI: 10.1093/jb/mvad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/30/2023] [Accepted: 04/09/2023] [Indexed: 04/27/2023] Open
Abstract
Accumulation of insoluble aggregates of infectious, partially protease-resistant prion protein (PrPD) generated via the misfolding of protease sensitive prion protein (PrPC) into the same infectious conformer, is a hallmark of prion diseases. Aggregated PrPD is taken up and degraded by cells, a process likely involving changes in aggregate structure that can be monitored by accessibility of the N-terminus of full-length PrPD to cellular proteases. We therefore tracked the protease sensitivity of full-length PrPD before and after cellular uptake for two murine prion strains, 22L and 87V. For both strains, PrPD aggregates were less stable following cellular uptake with increased accessibility of the N-terminus to cellular proteases across most aggregate sizes. However, a limited size range of aggregates was able to better protect the N-termini of full-length PrPD, with the N-terminus of 22L-derived PrPD more protected than that of 87V. Interestingly, changes in aggregate structure were associated with minimal changes to the protease-resistant core of PrPD. Our data show that cells destabilize the aggregate quaternary structure protecting PrPD from proteases in a strain-dependent manner, with structural changes exposing protease sensitive PrPD having little effect on the protease-resistant core, and thus conformation, of aggregated PrPD.
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Affiliation(s)
- Daniel Shoup
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy & Infectious Diseases, National Institutes of Health, 903 S. 4th Str, Hamilton, MT 59840 USA
| | - Suzette A Priola
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy & Infectious Diseases, National Institutes of Health, 903 S. 4th Str, Hamilton, MT 59840 USA
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4
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Prion Propagation is Dependent on Key Amino Acids in Charge Cluster 2 within the Prion Protein. J Mol Biol 2023; 435:167925. [PMID: 36535427 DOI: 10.1016/j.jmb.2022.167925] [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: 08/16/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
To dissect the N-terminal residues within the cellular prion protein (PrPC) that are critical for efficient prion propagation, we generated a library of point, double, or triple alanine replacements within residues 23-111 of PrP, stably expressed them in cells silenced for endogenous mouse PrPC and challenged the reconstituted cells with four common but biologically diverse mouse prion strains. Amino acids (aa) 105-111 of Charge Cluster 2 (CC2), which is disordered in PrPC, were found to be required for propagation of all four prion strains; other residues had no effect or exhibited strain-specific effects. Replacements in CC2, including aa105-111, dominantly inhibited prion propagation in the presence of endogenous wild type PrPC whilst other changes were not inhibitory. Single alanine replacements within aa105-111 identified leucine 108 and valine 111 or the cluster of lysine 105, threonine 106 and asparagine 107 as critical for prion propagation. These residues mediate specific ordering of unstructured CC2 into β-sheets in the infectious prion fibrils from Rocky Mountain Laboratory (RML) and ME7 mouse prion strains.
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5
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Igel A, Fornara B, Rezaei H, Béringue V. Prion assemblies: structural heterogeneity, mechanisms of formation, and role in species barrier. Cell Tissue Res 2022; 392:149-166. [PMID: 36399162 PMCID: PMC10113350 DOI: 10.1007/s00441-022-03700-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022]
Abstract
AbstractPrions are proteinaceous pathogens responsible for a wide range of neurodegenerative diseases in animal and human. Prions are formed from misfolded, ß-sheet rich, and aggregated conformers (PrPSc) of the host-encoded prion protein (PrPC). Prion replication stems from the capacity of PrPSc to self-replicate by templating PrPC conversion and polymerization. The question then arises about the molecular mechanisms of prion replication, host invasion, and capacity to contaminate other species. Studying these mechanisms has gained in recent years further complexity with evidence that PrPSc is a pleiomorphic protein. There is indeed compelling evidence for PrPSc structural heterogeneity at different scales: (i) within prion susceptible host populations with the existence of different strains with specific biological features due to different PrPSc conformers, (ii) within a single infected host with the co-propagation of different strains, and (iii) within a single strain with evidence for co-propagation of PrPSc assemblies differing in their secondary to quaternary structure. This review summarizes current knowledge of prion assembly heterogeneity, potential mechanisms of formation during the replication process, and importance when crossing the species barrier.
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6
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Reimann RR, Puzio M, Rosati A, Emmenegger M, Schneider BL, Valdés P, Huang D, Caflisch A, Aguzzi A. Rapid ex vivo reverse genetics identifies the essential determinants of prion protein toxicity. Brain Pathol 2022; 33:e13130. [PMID: 36329611 PMCID: PMC10041163 DOI: 10.1111/bpa.13130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
Abstract
The cellular prion protein PrPC mediates the neurotoxicity of prions and other protein aggregates through poorly understood mechanisms. Antibody-derived ligands against the globular domain of PrPC (GDL) can also initiate neurotoxicity by inducing an intramolecular R208 -H140 hydrogen bond ("H-latch") between the α2-α3 and β2-α2 loops of PrPC . Importantly, GDL that suppresses the H-latch prolong the life of prion-infected mice, suggesting that GDL toxicity and prion infections exploit convergent pathways. To define the structural underpinnings of these phenomena, we transduced 19 individual PrPC variants to PrPC -deficient cerebellar organotypic cultured slices using adenovirus-associated viral vectors (AAV). We report that GDL toxicity requires a single N-proximal cationic residue (K27 or R27 ) within PrPC . Alanine substitution of K27 also prevented the toxicity of PrPC mutants that induce Shmerling syndrome, a neurodegenerative disease that is suppressed by co-expression of wild-type PrPC . K27 may represent an actionable target for compounds aimed at preventing prion-related neurodegeneration.
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Affiliation(s)
| | - Martina Puzio
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Antonella Rosati
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Marc Emmenegger
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Bernard L. Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Pamela Valdés
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Danzhi Huang
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology University of Zurich Zurich Switzerland
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7
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Mohammadi B, Song F, Matamoros-Angles A, Shafiq M, Damme M, Puig B, Glatzel M, Altmeppen HC. Anchorless risk or released benefit? An updated view on the ADAM10-mediated shedding of the prion protein. Cell Tissue Res 2022; 392:215-234. [PMID: 35084572 PMCID: PMC10113312 DOI: 10.1007/s00441-022-03582-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/12/2022] [Indexed: 11/24/2022]
Abstract
The prion protein (PrP) is a broadly expressed glycoprotein linked with a multitude of (suggested) biological and pathological implications. Some of these roles seem to be due to constitutively generated proteolytic fragments of the protein. Among them is a soluble PrP form, which is released from the surface of neurons and other cell types by action of the metalloprotease ADAM10 in a process termed 'shedding'. The latter aspect is the focus of this review, which aims to provide a comprehensive overview on (i) the relevance of proteolytic processing in regulating cellular PrP functions, (ii) currently described involvement of shed PrP in neurodegenerative diseases (including prion diseases and Alzheimer's disease), (iii) shed PrP's expected roles in intercellular communication in many more (patho)physiological conditions (such as stroke, cancer or immune responses), (iv) and the need for improved research tools in respective (future) studies. Deeper mechanistic insight into roles played by PrP shedding and its resulting fragment may pave the way for improved diagnostics and future therapeutic approaches in diseases of the brain and beyond.
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Affiliation(s)
- Behnam Mohammadi
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- Working Group for Interdisciplinary Neurobiology and Immunology (INI Research), Hamburg, Germany
| | - Feizhi Song
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Andreu Matamoros-Angles
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Mohsin Shafiq
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Markus Damme
- Institute of Biochemistry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Berta Puig
- Department of Neurology, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
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8
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Panes JD, Saavedra P, Pineda B, Escobar K, Cuevas ME, Moraga-Cid G, Fuentealba J, Rivas CI, Rezaei H, Muñoz-Montesino C. PrP C as a Transducer of Physiological and Pathological Signals. Front Mol Neurosci 2021; 14:762918. [PMID: 34880726 PMCID: PMC8648500 DOI: 10.3389/fnmol.2021.762918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/18/2021] [Indexed: 11/13/2022] Open
Abstract
After the discovery of prion phenomenon, the physiological role of the cellular prion protein (PrP C ) remained elusive. In the past decades, molecular and cellular analysis has shed some light regarding interactions and functions of PrP C in health and disease. PrP C , which is located mainly at the plasma membrane of neuronal cells attached by a glycosylphosphatidylinositol (GPI) anchor, can act as a receptor or transducer from external signaling. Although the precise role of PrP C remains elusive, a variety of functions have been proposed for this protein, namely, neuronal excitability and viability. Although many issues must be solved to clearly define the role of PrP C , its connection to the central nervous system (CNS) and to several misfolding-associated diseases makes PrP C an interesting pharmacological target. In a physiological context, several reports have proposed that PrP C modulates synaptic transmission, interacting with various proteins, namely, ion pumps, channels, and metabotropic receptors. PrP C has also been implicated in the pathophysiological cell signaling induced by β-amyloid peptide that leads to synaptic dysfunction in the context of Alzheimer's disease (AD), as a mediator of Aβ-induced cell toxicity. Additionally, it has been implicated in other proteinopathies as well. In this review, we aimed to analyze the role of PrP C as a transducer of physiological and pathological signaling.
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Affiliation(s)
- Jessica D Panes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Paulina Saavedra
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Benjamin Pineda
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Kathleen Escobar
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Magdalena E Cuevas
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Coralia I Rivas
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Human Rezaei
- Virologie et Immunologie Moléculaires (VIM), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Jouy-en-Josas, France.,Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Versailles, France.,Université Paris-Saclay, Jouy-en-Josas, France
| | - Carola Muñoz-Montesino
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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9
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Prion Protein Biology Through the Lens of Liquid-Liquid Phase Separation. J Mol Biol 2021; 434:167368. [PMID: 34808226 DOI: 10.1016/j.jmb.2021.167368] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/12/2021] [Accepted: 11/14/2021] [Indexed: 12/29/2022]
Abstract
Conformational conversion of the α-helix-rich cellular prion protein into the misfolded, β-rich, aggregated, scrapie form underlies the molecular basis of prion diseases that represent a class of invariably fatal, untreatable, and transmissible neurodegenerative diseases. However, despite the extensive and rigorous research, there is a significant gap in the understanding of molecular mechanisms that contribute to prion pathogenesis. In this review, we describe the historical perspective of the development of the prion concept and the current state of knowledge of prion biology including structural, molecular, and cellular aspects of the prion protein. We then summarize the putative functional role of the N-terminal intrinsically disordered segment of the prion protein. We next describe the ongoing efforts in elucidating the prion phase behavior and the emerging role of liquid-liquid phase separation that can have potential functional relevance and can offer an alternate non-canonical pathway involving conformational conversion into a disease-associated form. We also attempt to shed light on the evolutionary perspective of the prion protein highlighting the potential role of intrinsic disorder in prion protein biology and summarize a few important questions associated with the phase transitions of the prion protein. Delving deeper into these key aspects can pave the way for a detailed understanding of the critical molecular determinants of the prion phase transition and its relevance to physiology and neurodegenerative diseases.
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10
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Virus Infection, Genetic Mutations, and Prion Infection in Prion Protein Conversion. Int J Mol Sci 2021; 22:ijms222212439. [PMID: 34830321 PMCID: PMC8624980 DOI: 10.3390/ijms222212439] [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: 10/28/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 01/04/2023] Open
Abstract
Conformational conversion of the cellular isoform of prion protein, PrPC, into the abnormally folded, amyloidogenic isoform, PrPSc, is an underlying pathogenic mechanism in prion diseases. The diseases manifest as sporadic, hereditary, and acquired disorders. Etiological mechanisms driving the conversion of PrPC into PrPSc are unknown in sporadic prion diseases, while prion infection and specific mutations in the PrP gene are known to cause the conversion of PrPC into PrPSc in acquired and hereditary prion diseases, respectively. We recently reported that a neurotropic strain of influenza A virus (IAV) induced the conversion of PrPC into PrPSc as well as formation of infectious prions in mouse neuroblastoma cells after infection, suggesting the causative role of the neuronal infection of IAV in sporadic prion diseases. Here, we discuss the conversion mechanism of PrPC into PrPSc in different types of prion diseases, by presenting our findings of the IAV infection-induced conversion of PrPC into PrPSc and by reviewing the so far reported transgenic animal models of hereditary prion diseases and the reverse genetic studies, which have revealed the structure-function relationship for PrPC to convert into PrPSc after prion infection.
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11
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Zhang X, Pan YH, Chen Y, Pan C, Ma J, Yuan C, Yu G, Ma J. The protease-sensitive N-terminal polybasic region of prion protein modulates its conversion to the pathogenic prion conformer. J Biol Chem 2021; 297:101344. [PMID: 34710372 PMCID: PMC8604679 DOI: 10.1016/j.jbc.2021.101344] [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: 07/19/2021] [Revised: 10/09/2021] [Accepted: 10/12/2021] [Indexed: 11/17/2022] Open
Abstract
Conversion of normal prion protein (PrPC) to the pathogenic PrPSc conformer is central to prion diseases such as Creutzfeldt-Jakob disease and scrapie; however, the detailed mechanism of this conversion remains obscure. To investigate how the N-terminal polybasic region of PrP (NPR) influences the PrPC-to-PrPSc conversion, we analyzed two PrP mutants: ΔN6 (deletion of all six amino acids in NPR) and Met4-1 (replacement of four positively charged amino acids in NPR with methionine). We found that ΔN6 and Met4-1 differentially impacted the binding of recombinant PrP (recPrP) to the negatively charged phospholipid 1-palmitoyl-2-oleoylphosphatidylglycerol, a nonprotein cofactor that facilitates PrP conversion. Both mutant recPrPs were able to form recombinant prion (recPrPSc) in vitro, but the convertibility was greatly reduced, with ΔN6 displaying the lowest convertibility. Prion infection assays in mammalian RK13 cells expressing WT or NPR-mutant PrPs confirmed these differences in convertibility, indicating that the NPR affects the conversion of both bacterially expressed recPrP and post-translationally modified PrP in eukaryotic cells. We also found that both WT and mutant recPrPSc conformers caused prion disease in WT mice with a 100% attack rate, but the incubation times and neuropathological changes caused by two recPrPSc mutants were significantly different from each other and from that of WT recPrPSc. Together, our results support that the NPR greatly influences PrPC-to-PrPSc conversion, but it is not essential for the generation of PrPSc. Moreover, the significant differences between ΔN6 and Met4-1 suggest that not only charge but also the identity of amino acids in NPR is important to PrP conversion.
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Affiliation(s)
- Xiangyi Zhang
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Yi-Hsuan Pan
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Ying Chen
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Chenhua Pan
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Ji Ma
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Chonggang Yuan
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Guohua Yu
- Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, School of Life Sciences, Longyan University, Longyan, China
| | - Jiyan Ma
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China; Department of Neurodegeneraive Science, Van Andel Institute, Grand Rapids, Michigan, USA; Chinese Institute for Brain Research, Beijing, China.
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12
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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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13
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Novel quaternary structures of the human prion protein globular domain. Biochimie 2021; 191:118-125. [PMID: 34517052 DOI: 10.1016/j.biochi.2021.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/30/2021] [Accepted: 09/07/2021] [Indexed: 11/22/2022]
Abstract
Prion disease is caused by the misfolding of the cellular prion protein, PrPC, into a self-templating conformer, PrPSc. Nuclear magnetic resonance (NMR) and X-ray crystallography revealed the 3D structure of the globular domain of PrPC and the possibility of its dimerization via an interchain disulfide bridge that forms due to domain swap or by non-covalent association of two monomers. On the contrary, PrPSc is composed by a complex and heterogeneous ensemble of poorly defined conformations and quaternary arrangements that are related to different patterns of neurotoxicity. Targeting PrPC with molecules that stabilize the native conformation of its globular domain emerged as a promising approach to develop anti-prion therapies. One of the advantages of this approach is employing structure-based drug discovery methods to PrPC. Thus, it is essential to expand our structural knowledge about PrPC as much as possible to aid such drug discovery efforts. In this work, we report a crystallographic structure of the globular domain of human PrPC that shows a novel dimeric form and a novel oligomeric arrangement. We use molecular dynamics simulations to explore its structural dynamics and stability and discuss potential implications of these new quaternary structures to the conversion process.
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14
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Legname G, Scialò C. On the role of the cellular prion protein in the uptake and signaling of pathological aggregates in neurodegenerative diseases. Prion 2021; 14:257-270. [PMID: 33345731 PMCID: PMC7757855 DOI: 10.1080/19336896.2020.1854034] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Neurodegenerative disorders are associated with intra- or extra-cellular deposition of aggregates of misfolded insoluble proteins. These deposits composed of tau, amyloid-β or α-synuclein spread from cell to cell, in a prion-like manner. Novel evidence suggests that the circulating soluble oligomeric species of these misfolded proteins could play a major role in pathology, while insoluble aggregates would represent their protective less toxic counterparts. Recent convincing data support the proposition that the cellular prion protein, PrPC, act as a toxicity-inducing receptor for amyloid-β oligomers. As a consequence, several studies focused their investigations to the role played by PrPC in binding other protein aggregates, such as tau and α-synuclein, for its possible common role in mediating toxic signalling. The biological relevance of PrPC as key ligand and potential mediator of toxicity for multiple proteinaceous aggregated species, prions or PrPSc included, could lead to relevant therapeutic implications. Here we describe the structure of PrPC and the proposed interplay with its pathological counterpart PrPSc and then we recapitulate the most recent findings regarding the role of PrPC in the interaction with aggregated forms of other neurodegeneration-associated proteins.
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Affiliation(s)
- Giuseppe Legname
- Department of Neuroscience, Laboratory of Prion Biology, Scuola Internazionale Superiore Di Studi Avanzati (SISSA) , Trieste, Italy
| | - Carlo Scialò
- Department of Neuroscience, Laboratory of Prion Biology, Scuola Internazionale Superiore Di Studi Avanzati (SISSA) , Trieste, Italy
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15
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Silva CJ, Erickson-Beltran ML, Dynin IC. Quantifying the Role of Lysine in Prion Replication by Nano-LC Mass Spectrometry and Bioassay. Front Bioeng Biotechnol 2020; 8:562953. [PMID: 33072723 PMCID: PMC7542330 DOI: 10.3389/fbioe.2020.562953] [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: 05/17/2020] [Accepted: 08/24/2020] [Indexed: 11/26/2022] Open
Abstract
Prions propagate by a template driven process, inducing the normal cellular isoform (PrPC) to adopt the prion (PrPSc) conformation. In PrPC, the positions of lysines are highly conserved and strongly influence prion propagation. In this study, covalent modification was used to quantitate the role of lysines in the PrPSc template that drives prion replication. The ε-amino group of lysines in the PrPSc (hamster-adapted scrapie Sc237) template was acetylated by either acetic anhydride (Ac2O) or the N-hydroxysuccinimide ester of acetic acid (Ac-NHS). The extent of lysine acetylation in PrPSc was quantitated by mass spectrometry or Western blot-based analysis. Identical samples were bioassayed to quantitate the loss of infectivity associated with lysine acetylation. The reduction of infectivity at the highest reagent concentration was approximately 90% (∼10-fold). Ten of the eleven prion lysines were acetylated to a greater extent (25−400-fold) than the observed loss of infectivity. Only one lysine, at position 220 (K220), had a reactivity that is consistent with the loss of infectivity. Although lysines are highly conserved and play a crucial role in converting PrPC into the PrPSc conformation, once that conformation is adopted, the lysines present in the PrPSc template play only a limited role in prion replication. In principle, this approach could be used to clarify the role of other amino acids in the replication of prions and other prion-like protein misfolding diseases.
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Affiliation(s)
- Christopher J Silva
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
| | - Melissa L Erickson-Beltran
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
| | - Irina C Dynin
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
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16
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Uchiyama K, Miyata H, Yamaguchi Y, Imamura M, Okazaki M, Pasiana AD, Chida J, Hara H, Atarashi R, Watanabe H, Kondoh G, Sakaguchi S. Strain-Dependent Prion Infection in Mice Expressing Prion Protein with Deletion of Central Residues 91-106. Int J Mol Sci 2020; 21:ijms21197260. [PMID: 33019549 PMCID: PMC7582732 DOI: 10.3390/ijms21197260] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 12/18/2022] Open
Abstract
Conformational conversion of the cellular prion protein, PrPC, into the abnormally folded isoform, PrPSc, is a key pathogenic event in prion diseases. However, the exact conversion mechanism remains largely unknown. Transgenic mice expressing PrP with a deletion of the central residues 91–106 were generated in the absence of endogenous PrPC, designated Tg(PrP∆91–106)/Prnp0/0 mice and intracerebrally inoculated with various prions. Tg(PrP∆91–106)/Prnp0/0 mice were resistant to RML, 22L and FK-1 prions, neither producing PrPSc∆91–106 or prions in the brain nor developing disease after inoculation. However, they remained marginally susceptible to bovine spongiform encephalopathy (BSE) prions, developing disease after elongated incubation times and accumulating PrPSc∆91–106 and prions in the brain after inoculation with BSE prions. Recombinant PrP∆91-104 converted into PrPSc∆91–104 after incubation with BSE-PrPSc-prions but not with RML- and 22L–PrPSc-prions, in a protein misfolding cyclic amplification assay. However, digitonin and heparin stimulated the conversion of PrP∆91–104 into PrPSc∆91–104 even after incubation with RML- and 22L-PrPSc-prions. These results suggest that residues 91–106 or 91–104 of PrPC are crucially involved in prion pathogenesis in a strain-dependent manner and may play a similar role to digitonin and heparin in the conversion of PrPC into PrPSc.
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Affiliation(s)
- Keiji Uchiyama
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
| | - Hironori Miyata
- Animal Research Center, School of Medicine, University of Occupational and Environmental Health, Yahatanishi, Kitakyushu 807-8555, Japan;
| | - Yoshitaka Yamaguchi
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
| | - Morikazu Imamura
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan; (M.I.); (R.A.)
| | - Mariya Okazaki
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
- Student Laboratory, Tokushima University, Faculty of Medicine, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | - Agriani Dini Pasiana
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
| | - Junji Chida
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
| | - Hideyuki Hara
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
| | - Ryuichiro Atarashi
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan; (M.I.); (R.A.)
| | - Hitomi Watanabe
- Laboratory of Integrative Biological Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan; (H.W.); (G.K.)
| | - Gen Kondoh
- Laboratory of Integrative Biological Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan; (H.W.); (G.K.)
| | - Suehiro Sakaguchi
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8503, Japan; (K.U.); (Y.Y.); (M.O.); (A.D.P.); (J.C.); (H.H.)
- Correspondence:
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17
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Scialò C, Legname G. The role of the cellular prion protein in the uptake and toxic signaling of pathological neurodegenerative aggregates. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 175:297-323. [PMID: 32958237 DOI: 10.1016/bs.pmbts.2020.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Neurodegenerative disorders are invariably associated with intra- or extra-cellular deposition of aggregates composed of misfolded insoluble proteins. These deposits composed of tau, amyloid-β or α-synuclein spread from cell to cell, in a prion-like manner. Emerging evidence suggests that the circulating soluble species of these misfolded proteins (usually referred as oligomers) could play a major role in pathology, while insoluble aggregates would represent their protective less toxic counterparts. Convincing data support the hypothesis that the cellular prion protein, PrPC, act as a toxicity-transducing receptor for amyloid-β oligomers. As a consequence, several studies extended investigations to the role played by PrPC in binding aggregates of proteins other than Aβ, such as tau and α-synuclein, for its possible common role in mediating toxic signaling. A better characterization of the biological relevance of PrPC as key ligand and potential mediator of toxicity for multiple proteinaceous aggregated species, prions or PrPSc included, would bring relevant therapeutic implications. Here we will first describe the structure of the prion protein and the hypothesized interplay with its pathological counterpart PrPSc and then we will recapitulate the most relevant discoveries regarding the role of PrPC in the interaction with aggregated forms of other neurodegeneration-associated proteins.
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Affiliation(s)
- Carlo Scialò
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy.
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18
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Hara H, Sakaguchi S. N-Terminal Regions of Prion Protein: Functions and Roles in Prion Diseases. Int J Mol Sci 2020; 21:ijms21176233. [PMID: 32872280 PMCID: PMC7504422 DOI: 10.3390/ijms21176233] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 01/30/2023] Open
Abstract
The normal cellular isoform of prion protein, designated PrPC, is constitutively converted to the abnormally folded, amyloidogenic isoform, PrPSc, in prion diseases, which include Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy in animals. PrPC is a membrane glycoprotein consisting of the non-structural N-terminal domain and the globular C-terminal domain. During conversion of PrPC to PrPSc, its 2/3 C-terminal region undergoes marked structural changes, forming a protease-resistant structure. In contrast, the N-terminal region remains protease-sensitive in PrPSc. Reverse genetic studies using reconstituted PrPC-knockout mice with various mutant PrP molecules have revealed that the N-terminal domain has an important role in the normal function of PrPC and the conversion of PrPC to PrPSc. The N-terminal domain includes various characteristic regions, such as the positively charged residue-rich polybasic region, the octapeptide repeat (OR) region consisting of five repeats of an octapeptide sequence, and the post-OR region with another positively charged residue-rich polybasic region followed by a stretch of hydrophobic residues. We discuss the normal functions of PrPC, the conversion of PrPC to PrPSc, and the neurotoxicity of PrPSc by focusing on the roles of the N-terminal regions in these topics.
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19
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Senatore A, Frontzek K, Emmenegger M, Chincisan A, Losa M, Reimann R, Horny G, Guo J, Fels S, Sorce S, Zhu C, George N, Ewert S, Pietzonka T, Hornemann S, Aguzzi A. Protective anti-prion antibodies in human immunoglobulin repertoires. EMBO Mol Med 2020; 12:e12739. [PMID: 32776637 PMCID: PMC7506995 DOI: 10.15252/emmm.202012739] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 01/09/2023] Open
Abstract
Prion immunotherapy may hold great potential, but antibodies against certain PrP epitopes can be neurotoxic. Here, we identified > 6,000 PrP-binding antibodies in a synthetic human Fab phage display library, 49 of which we characterized in detail. Antibodies directed against the flexible tail of PrP conferred neuroprotection against infectious prions. We then mined published repertoires of circulating B cells from healthy humans and found antibodies similar to the protective phage-derived antibodies. When expressed recombinantly, these antibodies exhibited anti-PrP reactivity. Furthermore, we surveyed 48,718 samples from 37,894 hospital patients for the presence of anti-PrP IgGs and found 21 high-titer individuals. The clinical files of these individuals did not reveal any enrichment of specific pathologies, suggesting that anti-PrP autoimmunity is innocuous. The existence of anti-prion antibodies in unbiased human immunological repertoires suggests that they might clear nascent prions early in life. Combined with the reported lack of such antibodies in carriers of disease-associated PRNP mutations, this suggests a link to the low incidence of spontaneous prion diseases in human populations.
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Affiliation(s)
- Assunta Senatore
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Karl Frontzek
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Marc Emmenegger
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Andra Chincisan
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Marco Losa
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Regina Reimann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Geraldine Horny
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Jingjing Guo
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Sylvie Fels
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Caihong Zhu
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Nathalie George
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Stefan Ewert
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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20
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Mohammadi B, Linsenmeier L, Shafiq M, Puig B, Galliciotti G, Giudici C, Willem M, Eden T, Koch-Nolte F, Lin YH, Tatzelt J, Glatzel M, Altmeppen HC. Transgenic Overexpression of the Disordered Prion Protein N1 Fragment in Mice Does Not Protect Against Neurodegenerative Diseases Due to Impaired ER Translocation. Mol Neurobiol 2020; 57:2812-2829. [PMID: 32367491 PMCID: PMC7253391 DOI: 10.1007/s12035-020-01917-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 04/07/2020] [Indexed: 12/14/2022]
Abstract
The structurally disordered N-terminal half of the prion protein (PrPC) is constitutively released into the extracellular space by an endogenous proteolytic cleavage event. Once liberated, this N1 fragment acts neuroprotective in ischemic conditions and interferes with toxic peptides associated with neurodegenerative diseases, such as amyloid-beta (Aβ) in Alzheimer’s disease. Since analog protective effects of N1 in prion diseases, such as Creutzfeldt-Jakob disease, have not been studied, and given that the protease releasing N1 has not been identified to date, we have generated and characterized transgenic mice overexpressing N1 (TgN1). Upon intracerebral inoculation of TgN1 mice with prions, no protective effects were observed at the levels of survival, clinical course, neuropathological, or molecular assessment. Likewise, primary neurons of these mice did not show protection against Aβ toxicity. Our biochemical and morphological analyses revealed that this lack of protective effects is seemingly due to an impaired ER translocation of the disordered N1 resulting in its cytosolic retention with an uncleaved signal peptide. Thus, TgN1 mice represent the first animal model to prove the inefficient ER translocation of intrinsically disordered domains (IDD). In contrast to earlier studies, our data challenge roles of cytoplasmic N1 as a cell penetrating peptide or as a potent “anti-prion” agent. Lastly, our study highlights both the importance of structured domains in the nascent chain for proteins to be translocated and aspects to be considered when devising novel N1-based therapeutic approaches against neurodegenerative diseases.
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Affiliation(s)
- Behnam Mohammadi
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Luise Linsenmeier
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Mohsin Shafiq
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Berta Puig
- Department of Neurology, Experimental Research in Stroke and Inflammation (ERSI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Giovanna Galliciotti
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Camilla Giudici
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Michael Willem
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Thomas Eden
- Institute of Immunology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Friedrich Koch-Nolte
- Institute of Immunology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Yu-Hsuan Lin
- Institute of Biochemistry and Pathobiochemistry, Biochemistry of Neurodegenerative Diseases, Ruhr University Bochum, Bochum, Germany
| | - Jörg Tatzelt
- Institute of Biochemistry and Pathobiochemistry, Biochemistry of Neurodegenerative Diseases, Ruhr University Bochum, Bochum, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Hermann C Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
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21
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The N-Terminal Polybasic Region of Prion Protein Is Crucial in Prion Pathogenesis Independently of the Octapeptide Repeat Region. Mol Neurobiol 2019; 57:1203-1216. [DOI: 10.1007/s12035-019-01804-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
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22
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Mengel D, Hong W, Corbett GT, Liu W, DeSousa A, Solforosi L, Fang C, Frosch MP, Collinge J, Harris DA, Walsh DM. PrP-grafted antibodies bind certain amyloid β-protein aggregates, but do not prevent toxicity. Brain Res 2019; 1710:125-135. [PMID: 30593771 PMCID: PMC6431553 DOI: 10.1016/j.brainres.2018.12.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/26/2018] [Accepted: 12/23/2018] [Indexed: 01/08/2023]
Abstract
BACKGROUND The prion protein (PrP) is known to bind certain soluble aggregates of the amyloid β-protein (Aβ), and two regions of PrP, one centered around residues 19-33, and the other around 87-112, are thought to be particularly important for this interaction. When either of these sequences are grafted into a human IgG the resulting antibodies react with disease-associated PrP conformers, whereas the parental b12 IgG does not. METHODS Human antibodies containing grafts of PrP 19-33 or 87-112 were prepared as before (Solforosi et al., 2007) and tested for their ability to recognize synthetic and Alzheimer's disease (AD) brain-derived Aβ. Since aqueous extracts of AD brain contain a complex mixture of active and inactive Aβ species, we also assessed whether PrP-grafted antibodies could protect against neuritotoxicity mediated by AD brain-derived Aβ. For these experiments, human iPSC-derived neurons were grown in 96-well plates at 5000 cells per well and on post-induction day 21, AD brain extracts were added +/- test antibodies. Neurons were imaged for 3 days using an IncuCyte live-cell imaging system, and neurite number and density quantified. RESULTS Grafted antibodies bound a significant portion of aggregated Aβ in aqueous AD extracts, but when these antibodies were co-incubated with neurons treated with brain extracts they did not reduce toxicity. By contrast, the PrP fragment N1 did protect against Aβ. CONCLUSIONS These results further demonstrate that not all Aβ oligomers are toxic and suggest that PrP derivatives may allow development of agents that differentially recognize toxic and innocuous Aβ aggregates.
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Affiliation(s)
- David Mengel
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Wei Hong
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Grant T Corbett
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Wen Liu
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Alexandra DeSousa
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Laura Solforosi
- Laboratory of Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy
| | - Cheng Fang
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Matthew P Frosch
- Massachusetts General Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - John Collinge
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; MRC Prion Unit at UCL, UCL Institute of Prion Diseases and NHS National Prion Clinic, UCL Hospitals NHS Foundation Trust, London, United Kingdom
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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23
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McDonald AJ, Leon DR, Markham KA, Wu B, Heckendorf CF, Schilling K, Showalter HD, Andrews PC, McComb ME, Pushie MJ, Costello CE, Millhauser GL, Harris DA. Altered Domain Structure of the Prion Protein Caused by Cu 2+ Binding and Functionally Relevant Mutations: Analysis by Cross-Linking, MS/MS, and NMR. Structure 2019; 27:907-922.e5. [PMID: 30956132 DOI: 10.1016/j.str.2019.03.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/17/2019] [Accepted: 03/14/2019] [Indexed: 12/24/2022]
Abstract
The cellular isoform of the prion protein (PrPC) serves as precursor to the infectious isoform (PrPSc), and as a cell-surface receptor, which binds misfolded protein oligomers as well as physiological ligands such as Cu2+ ions. PrPC consists of two domains: a flexible N-terminal domain and a structured C-terminal domain. Both the physiological and pathological functions of PrP depend on intramolecular interactions between these two domains, but the specific amino acid residues involved have proven challenging to define. Here, we employ a combination of chemical cross-linking, mass spectrometry, NMR, molecular dynamics simulations, and functional assays to identify residue-level contacts between the N- and C-terminal domains of PrPC. We also determine how these interdomain contacts are altered by binding of Cu2+ ions and by functionally relevant mutations. Our results provide a structural basis for interpreting both the normal and toxic activities of PrP.
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Affiliation(s)
- Alex J McDonald
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Deborah R Leon
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA; Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kathleen A Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Christian F Heckendorf
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA; Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kevin Schilling
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hollis D Showalter
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Philip C Andrews
- Department of Biological Chemistry, Department of Chemistry, Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mark E McComb
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA; Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA 02118, USA
| | - M Jake Pushie
- Department of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Catherine E Costello
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA; Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA.
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24
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Le NTT, Wu B, Harris DA. Prion neurotoxicity. Brain Pathol 2019; 29:263-277. [PMID: 30588688 DOI: 10.1111/bpa.12694] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/28/2018] [Indexed: 01/04/2023] Open
Abstract
Although the mechanisms underlying prion propagation and infectivity are now well established, the processes accounting for prion toxicity and pathogenesis have remained mysterious. These processes are of enormous clinical relevance as they hold the key to identification of new molecular targets for therapeutic intervention. In this review, we will discuss two broad areas of investigation relevant to understanding prion neurotoxicity. The first is the use of in vitro experimental systems that model key events in prion pathogenesis. In this context, we will describe a hippocampal neuronal culture system we developed that reproduces the earliest pathological alterations in synaptic morphology and function in response to PrPSc . This system has allowed us to define a core synaptotoxic signaling pathway involving the activation of NMDA and AMPA receptors, stimulation of p38 MAPK phosphorylation and collapse of the actin cytoskeleton in dendritic spines. The second area concerns a striking and unexpected phenomenon in which certain structural manipulations of the PrPC molecule itself, including introduction of N-terminal deletion mutations or binding of antibodies to C-terminal epitopes, unleash powerful toxic effects in cultured cells and transgenic mice. We will describe our studies of this phenomenon, which led to the recognition that it is related to the induction of large, abnormal ionic currents by the structurally altered PrP molecules. Our results suggest a model in which the flexible N-terminal domain of PrPC serves as a toxic effector which is regulated by intramolecular interactions with the globular C-terminal domain. Taken together, these two areas of study have provided important clues to underlying cellular and molecular mechanisms of prion neurotoxicity. Nevertheless, much remains to be done on this next frontier of prion science.
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Affiliation(s)
- Nhat T T Le
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
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25
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Fang C, Wu B, Le NTT, Imberdis T, Mercer RCC, Harris DA. Prions activate a p38 MAPK synaptotoxic signaling pathway. PLoS Pathog 2018; 14:e1007283. [PMID: 30235355 PMCID: PMC6147624 DOI: 10.1371/journal.ppat.1007283] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/15/2018] [Indexed: 11/19/2022] Open
Abstract
Synaptic degeneration is one of the earliest pathological correlates of prion disease, and it is a major determinant of the progression of clinical symptoms. However, the cellular and molecular mechanisms underlying prion synaptotoxicity are poorly understood. Previously, we described an experimental system in which treatment of cultured hippocampal neurons with purified PrPSc, the infectious form of the prion protein, induces rapid retraction of dendritic spines, an effect that is entirely dependent on expression of endogenous PrPC by the target neurons. Here, we use this system to dissect pharmacologically the underlying cellular and molecular mechanisms. We show that PrPSc initiates a stepwise synaptotoxic signaling cascade that includes activation of NMDA receptors, calcium influx, stimulation of p38 MAPK and several downstream kinases, and collapse of the actin cytoskeleton within dendritic spines. Synaptic degeneration is restricted to excitatory synapses, spares presynaptic structures, and results in decrements in functional synaptic transmission. Pharmacological inhibition of any one of the steps in the signaling cascade, as well as expression of a dominant-negative form of p38 MAPK, block PrPSc-induced spine degeneration. Moreover, p38 MAPK inhibitors actually reverse the degenerative process after it has already begun. We also show that, while PrPC mediates the synaptotoxic effects of both PrPSc and the Alzheimer’s Aβ peptide in this system, the two species activate distinct signaling pathways. Taken together, our results provide powerful insights into the biology of prion neurotoxicity, they identify new, druggable therapeutic targets, and they allow comparison of prion synaptotoxic pathways with those involved in other neurodegenerative diseases. Prion diseases are a group of fatal neurodegenerative disorders that includes Creutzfeldt-Jakob disease and kuru in humans, and bovine spongiform encephalopathy in cattle. The infectious agent, or prion, that transmits these diseases is a naked protein molecule, the prion protein (PrP), which is an altered form of a normal, cellular protein. Although a great deal is known about how prions propagate themselves and transmit infection, the process by which they actually cause neurons to degenerate has remained mysterious. Here, we have used a specialized neuronal culture system to dissect the cellular and molecular mechanisms by which prions damage synapses, the structures that connect nerve cells and that play a crucial role in learning, memory, and neurological disease. Our results define a stepwise molecular pathway underlying prion synaptic toxicity, which involves activation of glutamate neurotransmitter receptors, influx of calcium ions into the neuron, and stimulation of specific mitogen-activated protein kinases, which attach phosphate groups to proteins to regulate their activity. We demonstrate that specific drugs, as well as a dominant-negative kinase mutant, block these steps and thereby prevent the synaptic degeneration produced by prions. Our results provide new insights into the pathogenesis of prion diseases, they uncover new drug targets for treating these diseases, and they allow us to compare prion diseases to other, more common neurodegenerative disorders like Alzheimer’s disease.
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Affiliation(s)
- Cheng Fang
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Nhat T. T. Le
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Thibaut Imberdis
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Robert C. C. Mercer
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - David A. Harris
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
- * E-mail:
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Sarell CJ, Quarterman E, Yip DCM, Terry C, Nicoll AJ, Wadsworth JDF, Farrow MA, Walsh DM, Collinge J. Soluble Aβ aggregates can inhibit prion propagation. Open Biol 2018; 7:rsob.170158. [PMID: 29142106 PMCID: PMC5717343 DOI: 10.1098/rsob.170158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022] Open
Abstract
Mammalian prions cause lethal neurodegenerative diseases such as Creutzfeldt–Jakob disease (CJD) and consist of multi-chain assemblies of misfolded cellular prion protein (PrPC). Ligands that bind to PrPC can inhibit prion propagation and neurotoxicity. Extensive prior work established that certain soluble assemblies of the Alzheimer's disease (AD)-associated amyloid β-protein (Aβ) can tightly bind to PrPC, and that this interaction may be relevant to their toxicity in AD. Here, we investigated whether such soluble Aβ assemblies might, conversely, have an inhibitory effect on prion propagation. Using cellular models of prion infection and propagation and distinct Aβ preparations, we found that the form of Aβ assemblies which most avidly bound to PrP in vitro also inhibited prion infection and propagation. By contrast, forms of Aβ which exhibit little or no binding to PrP were unable to attenuate prion propagation. These data suggest that soluble aggregates of Aβ can compete with prions for binding to PrPC and emphasize the bidirectional nature of the interplay between Aβ and PrPC in Alzheimer's and prion diseases. Such inhibitory effects of Aβ on prion propagation may contribute to the apparent fall-off in the incidence of sporadic CJD at advanced age where cerebral Aβ deposition is common.
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Affiliation(s)
- Claire J Sarell
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Emma Quarterman
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Daniel C-M Yip
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Cassandra Terry
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Andrew J Nicoll
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jonathan D F Wadsworth
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Mark A Farrow
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Dominic M Walsh
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK .,Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - John Collinge
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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A Promising Antiprion Trimethoxychalcone Binds to the Globular Domain of the Cellular Prion Protein and Changes Its Cellular Location. Antimicrob Agents Chemother 2018; 62:AAC.01441-17. [PMID: 29133563 DOI: 10.1128/aac.01441-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/02/2017] [Indexed: 12/28/2022] Open
Abstract
The search for antiprion compounds has been encouraged by the fact that transmissible spongiform encephalopathies (TSEs) share molecular mechanisms with more prevalent neurodegenerative pathologies, such as Parkinson's and Alzheimer's diseases. Cellular prion protein (PrPC) conversion into protease-resistant forms (protease-resistant PrP [PrPRes] or the scrapie form of PrP [PrPSc]) is a critical step in the development of TSEs and is thus one of the main targets in the screening for antiprion compounds. In this work, three trimethoxychalcones (compounds J1, J8, and J20) and one oxadiazole (compound Y17), previously identified in vitro to be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrPC mRNA levels in N2a cells, as shown by reverse transcription-quantitative real-time PCR. Among them, J8 and Y17 were effective in real-time quaking-induced conversion reactions using rodent recombinant PrP (rPrP) from residues 23 to 231 (rPrP23-231) as the substrate and PrPSc seeds from hamster and human brain. However, when rPrP from residues 90 to 231 (rPrP90-231), which lacks the N-terminal domain, was used as the substrate, only J8 remained effective, indicating that this region is important for Y17 activity, while J8 seems to interact with the PrPC globular domain. J8 also reduced the fibrillation of mouse rPrP23-231 seeded with in vitro-produced fibrils. Furthermore, most of the compounds decreased the amount of PrPC on the N2a cell surface by trapping this protein in the endoplasmic reticulum. On the basis of these results, we hypothesize that J8, a nontoxic compound previously shown to be a promising antiprion agent, may act by different mechanisms, since its efficacy is attributable not only to PrP conversion inhibition but also to a reduction of the PrPC content on the cell surface.
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28
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McDonald AJ, Wu B, Harris DA. An inter-domain regulatory mechanism controls toxic activities of PrP C. Prion 2017; 11:388-397. [PMID: 28960140 DOI: 10.1080/19336896.2017.1384894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The normal function of PrPC, the cellular prion protein, has remained mysterious since its first description over 30 years ago. Amazingly, although complete deletion of the gene encoding PrPC has little phenotypic consequence, expression in transgenic mice of PrP molecules carrying certain internal deletions produces dramatic neurodegenerative phenotypes. In our recent paper, 1 we have demonstrated that the flexible, N-terminal domain of PrPC possesses toxic effector functions, which are regulated by a docking interaction with the structured, C-terminal domain. Disruption of this inter-domain interaction, for example by deletions of the hinge region or by binding of antibodies to the C-terminal domain, results in abnormal ionic currents and degeneration of dendritic spines in cultured neuronal cells. This mechanism may contribute to the neurotoxicity of PrPSc and possibly other protein aggregates, and could play a role in the physiological activity of PrPC. These results also provide a warning about the potential toxic side effects of PrP-directed antibody therapies for prion and Alzheimer's diseases.
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Affiliation(s)
- Alex J McDonald
- a Department of Biochemistry , Boston University School of Medicine , Boston , MA , USA
| | - Bei Wu
- a Department of Biochemistry , Boston University School of Medicine , Boston , MA , USA
| | - David A Harris
- a Department of Biochemistry , Boston University School of Medicine , Boston , MA , USA
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29
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Okamoto A, Hosoda N, Tanaka A, Newnam GP, Chernoff YO, Hoshino SI. Proteolysis suppresses spontaneous prion generation in yeast. J Biol Chem 2017; 292:20113-20124. [PMID: 29038292 DOI: 10.1074/jbc.m117.811323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/05/2017] [Indexed: 11/06/2022] Open
Abstract
Prions are infectious proteins that cause fatal neurodegenerative disorders including Creutzfeldt-Jakob and bovine spongiform encephalopathy (mad cow) diseases. The yeast [PSI+] prion is formed by the translation-termination factor Sup35, is the best-studied prion, and provides a useful model system for studying such diseases. However, despite recent progress in the understanding of prion diseases, the cellular defense mechanism against prions has not been elucidated. Here, we report that proteolytic cleavage of Sup35 suppresses spontaneous de novo generation of the [PSI+] prion. We found that during yeast growth in glucose media, a maximum of 40% of Sup35 is cleaved at its N-terminal prion domain. This cleavage requires the vacuolar proteases PrA-PrB. Cleavage occurs in a manner dependent on translation but independently of autophagy between the glutamine/asparagine-rich (Q/N-rich) stretch critical for prion formation and the oligopeptide-repeat region required for prion maintenance, resulting in the removal of the Q/N-rich stretch from the Sup35 N terminus. The complete inhibition of Sup35 cleavage, by knocking out either PrA (pep4Δ) or PrB (prb1Δ), increased the rate of de novo formation of [PSI+] prion up to ∼5-fold, whereas the activation of Sup35 cleavage, by overproducing PrB, inhibited [PSI+] formation. On the other hand, activation of the PrB pathway neither cleaved the amyloid conformers of Sup35 in [PSI+] strains nor eliminated preexisting [PSI+]. These findings point to a mechanism antagonizing prion generation in yeast. Our results underscore the usefulness of the yeast [PSI+] prion as a model system to investigate defense mechanisms against prion diseases and other amyloidoses.
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Affiliation(s)
- Atsushi Okamoto
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Nao Hosoda
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Anri Tanaka
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Gary P Newnam
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332-2000
| | - Yury O Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332-2000; Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Shin-Ichi Hoshino
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan.
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30
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Wu B, McDonald AJ, Markham K, Rich CB, McHugh KP, Tatzelt J, Colby DW, Millhauser GL, Harris DA. The N-terminus of the prion protein is a toxic effector regulated by the C-terminus. eLife 2017; 6:e23473. [PMID: 28527237 PMCID: PMC5469617 DOI: 10.7554/elife.23473] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/17/2017] [Indexed: 12/23/2022] Open
Abstract
PrPC, the cellular isoform of the prion protein, serves to transduce the neurotoxic effects of PrPSc, the infectious isoform, but how this occurs is mysterious. Here, using a combination of electrophysiological, cellular, and biophysical techniques, we show that the flexible, N-terminal domain of PrPC functions as a powerful toxicity-transducing effector whose activity is tightly regulated in cis by the globular C-terminal domain. Ligands binding to the N-terminal domain abolish the spontaneous ionic currents associated with neurotoxic mutants of PrP, and the isolated N-terminal domain induces currents when expressed in the absence of the C-terminal domain. Anti-PrP antibodies targeting epitopes in the C-terminal domain induce currents, and cause degeneration of dendrites on murine hippocampal neurons, effects that entirely dependent on the effector function of the N-terminus. NMR experiments demonstrate intramolecular docking between N- and C-terminal domains of PrPC, revealing a novel auto-inhibitory mechanism that regulates the functional activity of PrPC.
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Affiliation(s)
- Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Alex J McDonald
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kathleen Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - Celeste B Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kyle P McHugh
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Jörg Tatzelt
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University, Munich, Germany
| | - David W Colby
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
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Das NR, Miyata H, Hara H, Uchiyama K, Chida J, Yano M, Watanabe H, Kondoh G, Sakaguchi S. Effects of prion protein devoid of the N-terminal residues 25-50 on prion pathogenesis in mice. Arch Virol 2017; 162:1867-1876. [DOI: 10.1007/s00705-017-3295-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/02/2017] [Indexed: 12/23/2022]
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32
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Melanin or a Melanin-Like Substance Interacts with the N-Terminal Portion of Prion Protein and Inhibits Abnormal Prion Protein Formation in Prion-Infected Cells. J Virol 2017; 91:JVI.01862-16. [PMID: 28077650 DOI: 10.1128/jvi.01862-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 01/05/2017] [Indexed: 01/19/2023] Open
Abstract
Prion diseases are progressive fatal neurodegenerative illnesses caused by the accumulation of transmissible abnormal prion protein (PrP). To find treatments for prion diseases, we searched for substances from natural resources that inhibit abnormal PrP formation in prion-infected cells. We found that high-molecular-weight components from insect cuticle extracts reduced abnormal PrP levels. The chemical nature of these components was consistent with that of melanin. In fact, synthetic melanin produced from tyrosine or 3-hydroxy-l-tyrosine inhibited abnormal PrP formation. Melanin did not modify cellular or cell surface PrP levels, nor did it modify lipid raft or cellular cholesterol levels. Neither did it enhance autophagy or lysosomal function. Melanin was capable of interacting with PrP at two N-terminal domains. Specifically, it strongly interacted with the PrP region of amino acids 23 to 50 including a positively charged amino acid cluster and weakly interacted with the PrP octarepeat peptide region of residues 51 to 90. However, the in vitro and in vivo data were inconsistent with those of prion-infected cells. Abnormal PrP formation in protein misfolding cyclic amplification was not inhibited by melanin. Survival after prion infection was not significantly altered in albino mice or exogenously melanin-injected mice compared with that of control mice. These data suggest that melanin, a main determinant of skin color, is not likely to modify prion disease pathogenesis, even though racial differences in the incidence of human prion diseases have been reported. Thus, the findings identify an interaction between melanin and the N terminus of PrP, but the pathophysiological roles of the PrP-melanin interaction remain unclear.IMPORTANCE The N-terminal region of PrP is reportedly important for neuroprotection, neurotoxicity, and abnormal PrP formation, as this region is bound by many factors, such as metal ions, lipids, nucleic acids, antiprion compounds, and several proteins, including abnormal PrP in prion disease and the Aβ oligomer in Alzheimer's disease. In the present study, melanin, a main determinant of skin color, was newly found to interact with this N-terminal region and inhibits abnormal PrP formation in prion-infected cells. However, the data for prion infection in mice lacking melanin production suggest that melanin is not associated with the prion disease mechanism, although the incidence of prion disease is reportedly much higher in white people than in black people. Thus, the roles of the PrP-melanin interaction remain to be further elucidated, but melanin might be a useful competitive tool for evaluating the functions of other ligands at the N-terminal region.
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Abstract
Like numerous proteins of various structural and functional classes, the glycosylphosphatidylinositol (GPI)-anchored cellular prion protein (PrPC) has been recognized to undergo endoproteolytic processing for decades, a phenomenon observed in various cultured cell lines, as well as human and several animal tissue extracts. Despite this, the physiological significance of PrPC proteolytic cleavage has not yet been entirely elucidated. Experimental evidence suggests independent normal biological functions of the full-length and truncated PrPC species, as well as probable links of endoproteolysis to prion disease transmission susceptibility, pathogenesis, and toxicity. The accurate characterization of constitutive PrPC processing, through the method outlined in this chapter, is therefore an important tool in order to investigate the biological relevance of the alternative cleavage events.
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Affiliation(s)
- Victoria Lewis
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3010, Australia.
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Mukundan V, Maksoudian C, Vogel MC, Chehade I, Katsiotis MS, Alhassan SM, Magzoub M. Cytotoxicity of prion protein-derived cell-penetrating peptides is modulated by pH but independent of amyloid formation. Arch Biochem Biophys 2016; 613:31-42. [PMID: 27818203 DOI: 10.1016/j.abb.2016.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 10/30/2016] [Accepted: 11/02/2016] [Indexed: 11/25/2022]
Abstract
Prion diseases are associated with conversion of cellular prion protein (PrPC) into an abnormally folded and infectious scrapie isoform (PrPSc). We previously showed that peptides derived from the unprocessed N-termini of mouse and bovine prion proteins, mPrP1-28 and bPrP1-30, function as cell-penetrating peptides (CPPs), and destabilize model membrane systems, which could explain the infectivity and toxicity of prion diseases. However, subsequent studies revealed that treatment with mPrP1-28 or bPrP1-30 significantly reduce PrPSc levels in prion-infected cells. To explain these seemingly contradictory results, we correlated the aggregation, membrane perturbation and cytotoxicity of the peptides with their cellular uptake and intracellular localization. Although the peptides have a similar primary sequence, mPrP1-28 is amyloidogenic, whereas bPrP1-30 forms smaller oligomeric or non-fibrillar aggregates. Surprisingly, bPrP1-30 induces much higher cytotoxicity than mPrP1-28, indicating that amyloid formation and toxicity are independent. The toxicity is correlated with prolonged residence at the plasma membrane and membrane perturbation. Both ordered aggregation and toxicity of the peptides are inhibited by low pH. Under non-toxic conditions, the peptides are internalized by lipid-raft dependent macropinocytosis and localize to acidic lysosomal compartments. Our results shed light on the antiprion mechanism of the prion protein-derived CPPs and identify a potential site for PrPSc formation.
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Affiliation(s)
- Vineeth Mukundan
- Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Christy Maksoudian
- Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Maria C Vogel
- Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Ibrahim Chehade
- Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Marios S Katsiotis
- Department of Chemical Engineering, The Petroleum Institute, Abu Dhabi, United Arab Emirates
| | - Saeed M Alhassan
- Department of Chemical Engineering, The Petroleum Institute, Abu Dhabi, United Arab Emirates
| | - Mazin Magzoub
- Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
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35
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Imberdis T, Heeres JT, Yueh H, Fang C, Zhen J, Rich CB, Glicksman M, Beeler AB, Harris DA. Identification of Anti-prion Compounds using a Novel Cellular Assay. J Biol Chem 2016; 291:26164-26176. [PMID: 27803163 DOI: 10.1074/jbc.m116.745612] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/19/2016] [Indexed: 11/06/2022] Open
Abstract
Prion diseases are devastating neurodegenerative disorders with no known cure. One strategy for developing therapies for these diseases is to identify compounds that block conversion of the cellular form of the prion protein (PrPC) into the infectious isoform (PrPSc). Most previous efforts to discover such molecules by high-throughput screening methods have utilized, as a read-out, a single kind of cellular assay system: neuroblastoma cells that are persistently infected with scrapie prions. Here, we describe the use of an alternative cellular assay based on suppressing the spontaneous cytotoxicity of a mutant form of PrP (Δ105-125). Using this assay, we screened 75,000 compounds, and identified a group of phenethyl piperidines (exemplified by LD7), which reduces the accumulation of PrPSc in infected neuroblastoma cells by >90% at low micromolar doses, and inhibits PrPSc-induced synaptotoxicity in hippocampal neurons. By analyzing the structure-activity relationships of 35 chemical derivatives, we defined the pharmacophore of LD7, and identified a more potent derivative. Active compounds do not alter total or cell-surface levels of PrPC, and do not bind to recombinant PrP in surface plasmon resonance experiments, although at high concentrations they inhibit PrPSc-seeded conversion of recombinant PrP to a misfolded state in an in vitro reaction (RT-QuIC). This class of small molecules may provide valuable therapeutic leads, as well as chemical biological tools to identify cellular pathways underlying PrPSc metabolism and PrPC function.
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Affiliation(s)
- Thibaut Imberdis
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - James T Heeres
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Han Yueh
- the Department of Chemistry, Boston University, Boston, Massachusetts 02115, and
| | - Cheng Fang
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Jessie Zhen
- the Department of Chemistry, Boston University, Boston, Massachusetts 02115, and
| | - Celeste B Rich
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Marcie Glicksman
- the Laboratory for Drug Discovery in Neurodegeneration, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts 02139
| | - Aaron B Beeler
- the Department of Chemistry, Boston University, Boston, Massachusetts 02115, and
| | - David A Harris
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118,
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Baskakov IV, Katorcha E. Multifaceted Role of Sialylation in Prion Diseases. Front Neurosci 2016; 10:358. [PMID: 27551257 PMCID: PMC4976111 DOI: 10.3389/fnins.2016.00358] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/18/2016] [Indexed: 11/13/2022] Open
Abstract
Mammalian prion or PrP(Sc) is a proteinaceous infectious agent that consists of a misfolded, self-replicating state of a sialoglycoprotein called the prion protein, or PrP(C). Sialylation of the prion protein N-linked glycans was discovered more than 30 years ago, yet the role of sialylation in prion pathogenesis remains poorly understood. Recent years have witnessed extraordinary growth in interest in sialylation and established a critical role for sialic acids in host invasion and host-pathogen interactions. This review article summarizes current knowledge on the role of sialylation of the prion protein in prion diseases. First, we discuss the correlation between sialylation of PrP(Sc) glycans and prion infectivity and describe the factors that control sialylation of PrP(Sc). Second, we explain how glycan sialylation contributes to the prion replication barrier, defines strain-specific glycoform ratios, and imposes constraints for PrP(Sc) structure. Third, several topics, including a possible role for sialylation in animal-to-human prion transmission, prion lymphotropism, toxicity, strain interference, and normal function of PrP(C), are critically reviewed. Finally, a metabolic hypothesis on the role of sialylation in the etiology of sporadic prion diseases is proposed.
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Affiliation(s)
- Ilia V. Baskakov
- Department of Anatomy and Neurobiology, Center for Biomedical Engineering and Technology, University of Maryland School of MedicineBaltimore, MD, USA
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Yen CF, Harischandra DS, Kanthasamy A, Sivasankar S. Copper-induced structural conversion templates prion protein oligomerization and neurotoxicity. SCIENCE ADVANCES 2016; 2:e1600014. [PMID: 27419232 PMCID: PMC4942324 DOI: 10.1126/sciadv.1600014] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 05/27/2016] [Indexed: 05/26/2023]
Abstract
Prion protein (PrP) misfolding and oligomerization are key pathogenic events in prion disease. Copper exposure has been linked to prion pathogenesis; however, its mechanistic basis is unknown. We resolve, with single-molecule precision, the molecular mechanism of Cu(2+)-induced misfolding of PrP under physiological conditions. We also demonstrate that misfolded PrPs serve as seeds for templated formation of aggregates, which mediate inflammation and degeneration of neuronal tissue. Using a single-molecule fluorescence assay, we demonstrate that Cu(2+) induces PrP monomers to misfold before oligomer assembly; the disordered amino-terminal region mediates this structural change. Single-molecule force spectroscopy measurements show that the misfolded monomers have a 900-fold higher binding affinity compared to the native isoform, which promotes their oligomerization. Real-time quaking-induced conversion demonstrates that misfolded PrPs serve as seeds that template amyloid formation. Finally, organotypic slice cultures show that misfolded PrPs mediate inflammation and degeneration of neuronal tissue. Our study establishes a direct link, at the molecular level, between copper exposure and PrP neurotoxicity.
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Affiliation(s)
- Chi-Fu Yen
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA
| | - Dilshan S. Harischandra
- Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Anumantha Kanthasamy
- Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sanjeevi Sivasankar
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
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A Neuronal Culture System to Detect Prion Synaptotoxicity. PLoS Pathog 2016; 12:e1005623. [PMID: 27227882 PMCID: PMC4881977 DOI: 10.1371/journal.ppat.1005623] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/19/2016] [Indexed: 12/02/2022] Open
Abstract
Synaptic pathology is an early feature of prion as well as other neurodegenerative diseases. Although the self-templating process by which prions propagate is well established, the mechanisms by which prions cause synaptotoxicity are poorly understood, due largely to the absence of experimentally tractable cell culture models. Here, we report that exposure of cultured hippocampal neurons to PrPSc, the infectious isoform of the prion protein, results in rapid retraction of dendritic spines. This effect is entirely dependent on expression of the cellular prion protein, PrPC, by target neurons, and on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic loss. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents. Prion diseases are fatal neurodegenerative disorders that cause memory loss, impaired coordination, and abnormal movements. The molecular culprit in prion diseases is PrPSc, an infectious isoform of a host-encoded glycoprotein (PrPC) that can propagate itself by a self-templating mechanism. Whether PrPSc itself is toxic to neurons, and if so, the cellular mechanisms by which it produces neuronal pathology are largely unknown, in part because of the absence of suitable cell culture models. We describe here a hippocampal neuronal cultural system to detect the toxic effect of PrPSc on dendritic spines, which are postsynaptic elements responsible for excitatory synaptic transmission, and which are implicated in learning, memory, and the earliest stages of neurodegenerative diseases. We found that purified, exogenously applied PrPSc causes acute retraction of dendritic spines, an effect that is entirely dependent on expression of PrPC by target neurons, and on the on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic retraction. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents.
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Glatzel M, Linsenmeier L, Dohler F, Krasemann S, Puig B, Altmeppen HC. Shedding light on prion disease. Prion 2016; 9:244-56. [PMID: 26186508 DOI: 10.1080/19336896.2015.1065371] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Proteolytic processing regulates key processes in health and disease. The cellular prion protein (PrP(C)) is subject to at least 3 cleavage events, α-cleavage, β-cleavage and shedding. In contrast to α- and β-cleavage where there is an ongoing controversy on the identity of relevant proteases, the metalloprotease ADAM10 represents the only relevant PrP sheddase. Here we focus on the roles that ADAM10-mediated shedding of PrP(C) and its pathogenic isoform (PrP(Sc)) might play in regulating their physiological and pathogenic functions, respectively. As revealed by our recent study using conditional ADAM10 knockout mice (Altmeppen et al., 2015), shedding of PrP seems to be involved in key processes of prion diseases. These aspects and several open questions arising from them are discussed. Increased knowledge on this topic can shed new light on prion diseases and other neurodegenerative conditions as well.
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Affiliation(s)
- Markus Glatzel
- a Institute of Neuropathology; University Medical Center Hamburg-Eppendorf ; Hamburg , Germany
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Wang B, Lou Z, Zhang H, Xu B. Effect of the electrostatic surface potential on the oligomerization of full-length human recombinant prion protein at single-molecule level. J Chem Phys 2016; 144:114701. [DOI: 10.1063/1.4943878] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Bin Wang
- Single Molecule Study Laboratory, College of Engineering and Nanoscale Science, and Engineering Center, University of Georgia, Athens, Georgia 30605, USA
| | - Zhichao Lou
- Single Molecule Study Laboratory, College of Engineering and Nanoscale Science, and Engineering Center, University of Georgia, Athens, Georgia 30605, USA
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People’s Republic of China
| | - Haiqian Zhang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People’s Republic of China
| | - Bingqian Xu
- Single Molecule Study Laboratory, College of Engineering and Nanoscale Science, and Engineering Center, University of Georgia, Athens, Georgia 30605, USA
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Mutated but Not Deleted Ovine PrP(C) N-Terminal Polybasic Region Strongly Interferes with Prion Propagation in Transgenic Mice. J Virol 2015; 90:1638-46. [PMID: 26608316 DOI: 10.1128/jvi.02805-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 11/18/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Mammalian prions are proteinaceous infectious agents composed of misfolded assemblies of the host-encoded, cellular prion protein (PrP). Physiologically, the N-terminal polybasic region of residues 23 to 31 of PrP has been shown to be involved in its endocytic trafficking and interactions with glycosaminoglycans or putative ectodomains of membrane-associated proteins. Several recent reports also describe this PrP region as important for the toxicity of mutant prion proteins and the efficiency of prion propagation, both in vitro and in vivo. The question remains as to whether the latter observations made with mouse PrP and mouse prions would be relevant to other PrP species/prion strain combinations given the dramatic impact on prion susceptibility of minimal amino acid substitutions and structural variations in PrP. Here, we report that transgenic mouse lines expressing ovine PrP with a deletion of residues 23 to 26 (KKRP) or mutated in this N-terminal region (KQHPH instead of KKRPK) exhibited a variable, strain-dependent susceptibility to prion infection with regard to the proportion of affected mice and disease tempo relative to findings in their wild-type counterparts. Deletion has no major effect on 127S scrapie prion pathogenesis, whereas mutation increased by almost 3-fold the survival time of the mice. Deletion marginally affected the incubation time of scrapie LA19K and ovine bovine spongiform encephalopathy (BSE) prions, whereas mutation caused apparent resistance to disease. IMPORTANCE Recent reports suggested that the N-terminal polybasic region of the prion protein could be a therapeutic target to prevent prion propagation or toxic signaling associated with more common neurodegenerative diseases such as Alzheimer's disease. Mutating or deleting this region in ovine PrP completes the data previously obtained with the mouse protein by identifying the key amino acid residues involved.
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Iraci N, Stincardini C, Barreca ML, Biasini E. Decoding the function of the N-terminal tail of the cellular prion protein to inspire novel therapeutic avenues for neurodegenerative diseases. Virus Res 2015; 207:62-8. [DOI: 10.1016/j.virusres.2014.10.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/18/2014] [Accepted: 10/14/2014] [Indexed: 01/13/2023]
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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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Haigh CL, McGlade AR, Collins SJ. MEK1 transduces the prion protein N2 fragment antioxidant effects. Cell Mol Life Sci 2015; 72:1613-29. [PMID: 25391659 PMCID: PMC11114014 DOI: 10.1007/s00018-014-1777-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/13/2014] [Accepted: 11/06/2014] [Indexed: 10/24/2022]
Abstract
The prion protein (PrP(C)) when mis-folded is causally linked with a group of fatal neurodegenerative diseases called transmissible spongiform encephalopathies or prion diseases. PrP(C) normal function is still incompletely defined with such investigations complicated by PrP(C) post-translational modifications, such as internal cleavage, which feasibly could change, activate, or deactivate the function of this protein. Oxidative stress induces β-cleavage and the N-terminal product of this cleavage event, N2, demonstrates a cellular protective response against oxidative stress. The mechanisms by which N2 mediates cellular antioxidant protection were investigated within an in vitro cell model. N2 protection was regulated by copper binding to the octarepeat domain, directing the route of internalisation, which stimulated MEK1 signalling. Precise membrane interactions of N2, determined by copper saturation, and involving both the copper-co-ordinating octarepeat region and the structure conferred upon the N-terminal polybasic region by the proline motif, were essential for the correct engagement of this pathway. The phenomenon of PrP(C) post-translational modification, such as cleavage and copper co-ordination, as a molecular "switch" for activation or deactivation of certain functions provides new insight into the apparent multi-functionality of PrP(C).
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Affiliation(s)
- C. L. Haigh
- Department of Pathology, Melbourne Brain Centre, The University of Melbourne, Parkville, Melbourne, 3010 Australia
| | - A. R. McGlade
- Department of Pathology, Melbourne Brain Centre, The University of Melbourne, Parkville, Melbourne, 3010 Australia
- Mental Health Research Institute, The University of Melbourne, Parkville, Melbourne, 3010 Australia
| | - S. J. Collins
- Department of Pathology, Melbourne Brain Centre, The University of Melbourne, Parkville, Melbourne, 3010 Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC 3010 Australia
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45
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Didonna A, Venturini AC, Hartman K, Vranac T, Čurin Šerbec V, Legname G. Characterization of four new monoclonal antibodies against the distal N-terminal region of PrP(c). PeerJ 2015; 3:e811. [PMID: 25802800 PMCID: PMC4369333 DOI: 10.7717/peerj.811] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 02/11/2015] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders that affect humans and animals. They are characterized by the accumulation in the central nervous system of a pathological form of the host-encoded prion protein (PrPC). The prion protein is a membrane glycoprotein that consists of two domains: a globular, structured C-terminus and an unstructured N-terminus. The N-terminal part of the protein is involved in different functions in both health and disease. In the present work we discuss the production and biochemical characterization of a panel of four monoclonal antibodies (mAbs) against the distal N-terminus of PrPC using a well-established methodology based on the immunization of Prnp0/0 mice. Additionally, we show their ability to block prion (PrPSc) replication at nanomolar concentrations in a cell culture model of prion infection. These mAbs represent a promising tool for prion diagnostics and for studying the physiological role of the N-terminal domain of PrPC.
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Affiliation(s)
- Alessandro Didonna
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Anja Colja Venturini
- Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia
| | - Katrina Hartman
- Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia
| | - Tanja Vranac
- Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia
| | - Vladka Čurin Šerbec
- Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia
| | - Giuseppe Legname
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.,ELETTRA-Sincrotrone Trieste S.C.p.A, Trieste, Italy
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46
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Rouget R, Sharma G, LeBlanc AC. Cyclin-dependent kinase 5 phosphorylation of familial prion protein mutants exacerbates conversion into amyloid structure. J Biol Chem 2015; 290:5759-71. [PMID: 25572400 DOI: 10.1074/jbc.m114.630699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Familial prion protein (PrP) mutants undergo conversion from soluble and protease-sensitive to insoluble and partially protease-resistant proteins. Cyclin-dependent kinase 5 (Cdk5) phosphorylation of wild type PrP (pPrP) at serine 43 induces a conversion of PrP into aggregates and fibrils. Here, we investigated whether familial PrP mutants are predisposed to Cdk5 phosphorylation and whether phosphorylation of familial PrP mutants increases conversion. PrP mutants representing three major familial PrP diseases and different PrP structural domains were studied. We developed a novel in vitro kinase reaction coupled with Thioflavin T binding to amyloid structure assay to monitor phosphorylation-dependent amyloid conversion. Although non-phosphorylated full-length wild type or PrP mutants did not convert into amyloid, Cdk5 phosphorylation rapidly converted these into Thioflavin T-positive structures following first order kinetics. Dephosphorylation partially reversed conversion. Phosphorylation-dependent conversion of PrP from α-helical structures into β-sheet structures was confirmed by circular dichroism. Relative to wild type pPrP, most PrP mutants showed increased rate constants of conversion. In contrast, non-phosphorylated truncated PrP Y145X (where X represents a stop codon) and Q160X mutants converted spontaneously into Thioflavin T-positive fibrils after a lag phase of over 20 h, indicating nucleation-dependent polymerization. Phosphorylation reduced the lag phase by over 50% and thus accelerated the formation of the nucleating event. Consistently, phosphorylated Y145X and phosphorylated Q160X exacerbated conversion in a homologous seeding reaction, whereas WT pPrP could not seed WT PrP. These results demonstrate an influence of both the N terminus and the C terminus of PrP on conversion. We conclude that post-translational modifications of the flexible N terminus of PrP can cause or exacerbate PrP mutant conversion.
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Affiliation(s)
- Raphaël Rouget
- From the Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3T 1E2, Canada and
| | - Gyanesh Sharma
- From the Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3T 1E2, Canada and Department of Neurology and Neurosurgery, McGill University, 3775 University Street, Montréal, Québec H3A 2B4, Canada
| | - Andréa C LeBlanc
- From the Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3T 1E2, Canada and Department of Neurology and Neurosurgery, McGill University, 3775 University Street, Montréal, Québec H3A 2B4, Canada
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Béland M, Roucou X. Taking advantage of physiological proteolytic processing of the prion protein for a therapeutic perspective in prion and Alzheimer diseases. Prion 2015; 8:106-10. [PMID: 24335160 DOI: 10.4161/pri.27438] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prion and Alzheimer diseases are fatal neurodegenerative diseases caused by misfolding and aggregation of the cellular prion protein (PrP(C)) and the β-amyloid peptide, respectively. Soluble oligomeric species rather than large aggregates are now believed to be neurotoxic. PrP(C) undergoes three proteolytic cleavages as part of its natural life cycle, α-cleavage, β-cleavage, and ectodomain shedding. Recent evidences demonstrate that the resulting secreted PrP(C) molecules might represent natural inhibitors against soluble toxic species. In this mini-review, we summarize recent observations suggesting the potential benefit of using PrP(C)-derived molecules as therapeutic agents in prion and Alzheimer diseases.
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48
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Altmeppen HC, Prox J, Krasemann S, Puig B, Kruszewski K, Dohler F, Bernreuther C, Hoxha A, Linsenmeier L, Sikorska B, Liberski PP, Bartsch U, Saftig P, Glatzel M. The sheddase ADAM10 is a potent modulator of prion disease. eLife 2015; 4. [PMID: 25654651 PMCID: PMC4346534 DOI: 10.7554/elife.04260] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 02/04/2015] [Indexed: 01/10/2023] Open
Abstract
The prion protein (PrPC) is highly expressed in the nervous system and critically involved in prion diseases where it misfolds into pathogenic PrPSc. Moreover, it has been suggested as a receptor mediating neurotoxicity in common neurodegenerative proteinopathies such as Alzheimer's disease. PrPC is shed at the plasma membrane by the metalloprotease ADAM10, yet the impact of this on prion disease remains enigmatic. Employing conditional knockout mice, we show that depletion of ADAM10 in forebrain neurons leads to posttranslational increase of PrPC levels. Upon prion infection of these mice, clinical, biochemical, and morphological data reveal that lack of ADAM10 significantly reduces incubation times and increases PrPSc formation. In contrast, spatiotemporal analysis indicates that absence of shedding impairs spread of prion pathology. Our data support a dual role for ADAM10-mediated shedding and highlight the role of proteolytic processing in prion disease. DOI:http://dx.doi.org/10.7554/eLife.04260.001 Prion proteins are anchored to the surface of brain cells called neurons. Normally, prion proteins are folded into a specific three-dimensional shape that enables them to carry out their normal roles in the brain. However, they can be misfolded into a different shape known as PrPSc, which can cause Creutzfeldt-Jakob disease and other serious conditions that affect brain function and ultimately lead to death. The PrPSc proteins can force normal prion proteins to change into the PrPSc form, so that over time this form accumulates in the brain. They are essential components of infectious particles termed ‘prions’ and this is why prion diseases are infectious: if prions from one individual enter the brain of another individual they can cause disease in the recipient. The UK outbreak of variant Creutzfeldt-Jakob disease in humans in the 1990s is thought to be due to the consumption of meat from cattle with a prion disease known as mad cow disease. An enzyme called ADAM10 can cut normal prion proteins from the surface of neurons. However, it is not clear whether ADAM10 can also target the PrPSc proteins and what impact this may have on the development of prion diseases. Here, Altmeppen et al. studied mutant mice that were missing ADAM10 in neurons in the front portion of their brain. These mice had a higher number of normal prion proteins on the surface of their neurons than normal mice did. When mice missing ADAM10 were infected with prions, more PrPSc accumulated in their brain and disease symptoms developed sooner than when normal mice were infected. This supports the view that mice with higher numbers of prion proteins are more vulnerable to prion disease. However, disease symptoms did not spread as quickly to other parts of the brain in the mice missing ADAM10. This suggests that by releasing prion proteins from the surface of neurons, ADAM10 helps PrPSc proteins to spread around the brain. Recently, it has been suggested that prion proteins may also play a role in Alzheimer's disease and other neurodegenerative conditions. Therefore, Altmeppen et al.'s findings may help to develop new therapies for other forms of dementia. The next challenge is to understand the precise details of how ADAM10 works. DOI:http://dx.doi.org/10.7554/eLife.04260.002
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Affiliation(s)
- Hermann C Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Johannes Prox
- Institute of Biochemistry, Christian Albrechts University, Kiel, Germany
| | - Susanne Krasemann
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Berta Puig
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katharina Kruszewski
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frank Dohler
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Bernreuther
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ana Hoxha
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Luise Linsenmeier
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Beata Sikorska
- Department of Molecular Pathology and Neuropathology, Medical University Lodz, Lodz, Poland
| | - Pawel P Liberski
- Department of Molecular Pathology and Neuropathology, Medical University Lodz, Lodz, Poland
| | - Udo Bartsch
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paul Saftig
- Institute of Biochemistry, Christian Albrechts University, Kiel, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Kim DH, Lee HM, Ryou C. Evaluation of infective property of recombinant prion protein amyloids in cultured cells overexpressing cellular prion protein. J Korean Med Sci 2014; 29:1604-9. [PMID: 25469058 PMCID: PMC4248579 DOI: 10.3346/jkms.2014.29.12.1604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/06/2014] [Indexed: 11/22/2022] Open
Abstract
Misfolded isoform of prion protein (PrP), termed scrapie PrP (PrP(Sc)), tends to aggregate into various fibril forms. Previously, we reported various conditions that affect aggregation of recombinant PrP into amyloids. Because amyloidogenesis of PrP is closely associated with transmissible spongiform encephalopathies such as Creutzfeldt-Jakob disease in humans, we investigated infectivity of recombinant PrP amyloids generated in vitro. Using cultured cell lines which overexpress cellular PrP of different species, we measured the level of de novo synthesized PrP(Sc) in cells inoculated with recombinant mouse PrP amyloids. While PrP-overexpressing cells were susceptible to mouse-adapted scrapie prions used as the positive control, demonstrating the species barrier effect, infection with amyloids made of truncated recombinant PrP (PrP[89-230]) failed to form and propagate PrP(Sc) even in the cells that express mouse cellular PrP. This suggests that infectivity of PrP amyloids generated in vitro is different from that of natural prions. Recombinant PrP (89-230) amyloids tested in the current study retain no or a minute level, if any, of prion infectivity.
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Affiliation(s)
- Dae-Hwan Kim
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Korea
| | - Hye-Mi Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Korea
| | - Chongsuk Ryou
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Korea
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50
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Söderberg KL, Guterstam P, Langel U, Gräslund A. Targeting prion propagation using peptide constructs with signal sequence motifs. Arch Biochem Biophys 2014; 564:254-61. [PMID: 25447819 DOI: 10.1016/j.abb.2014.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 12/25/2022]
Abstract
Synthetic peptides with sequences derived from the cellular prion protein (PrP(C)) unprocessed N-terminus are able to counteract the propagation of proteinase K resistant prions (PrP(Res), indicating the presence of the prion isoform of the prion protein) in cell cultures (Löfgren et al., 2008). The anti-prion peptides have characteristics like cell penetrating peptides (CPPs) and consist of the prion protein hydrophobic signal sequence followed by a polycationic motif (residues KKRPKP), in mouse PrP(C) corresponding to residues 1-28. Here we analyze the sequence elements required for the anti-prion effect of KKRPKP-conjugates. Neuronal GT1-1 cells were infected with either prion strain RML or 22L. Variable peptide constructs originating from the mPrP1-28 sequence were analyzed for anti-prion effects, measured as disappearance of proteinase K resistant prions (PrP(Res)) in the infected cell cultures. We find that even a 5 amino acid N-terminal shortening of the signal peptide abolishes the anti-prion effect. We show that the signal peptide from PrP(C) can be replaced with the signal peptide from the Neural cell adhesion molecule-1; NCAM11-19, with a retained capacity to reduce PrP(Res) levels. The anti-prion effect is lost if the polycationic N-terminal PrP(C)-motif is conjugated to any conventional CPP, such as TAT48-60, transportan-10 or penetratin. We propose a mechanism by which a signal peptide from a secretory or cell surface protein acts to promote the transport of a prion-binding polycationic PrP(C)-motif to a subcellular location where prion conversion occurs (most likely the Endosome Recycling Compartment), thereby targeting prion propagation.
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Affiliation(s)
- Kajsa Löfgren Söderberg
- The Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Peter Guterstam
- The Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ulo Langel
- The Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Astrid Gräslund
- The Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden.
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