The channel activities of the full-length prion and truncated proteins

Prion disease is a fatal neurodegenerative disorder, in which the cellular prion protein PrPC is converted to a misfolded prion which in turn is hypothesized to permeabilize cellular membranes. The pathways leading to toxicity in prion disease are not yet completely elucidated and whether it also includes formation of membrane pores remains to be answered. Prion protein consists of two domains: a globular domain (GD) and a flexible N-terminus (FT) domain. Although a proximal nine polybasic amino acid (FT(23-31)) sequence of FT is a prerequisite for cellular membrane permeabilization, other functional domain regions may influence FT(23-31) and its permeabilization. By using single-channel electrical recordings, we reveal that FT(23-50) dominates the membrane permeabilization within the full-length mouse PrP (mPrP(23-230)). The other domain of FT(51-110) or C-terminal domain down-regulates the channel activity of FT(23-50) and the full-length mouse PrP (mPrP(23-230)). The addition of prion mimetic antibody, POM1 significantly enhances mPrP(23-230) membrane permeabilization, whereas POM1-Y104A, a POM1 mutant that binds to PrP but cannot elicit toxicity has negligible effect on membrane permeabilization. Additionally, anti-N-terminal antibody POM2 or Cu2+ stabilizes FT domain, thus provoking FT(23-110) channel activity. Furthermore, our setup provides a more direct method without an external fused protein to study the channel activity of truncated PrP in the lipid membranes. We therefore hypothesize that the primary N-terminal residues are essential for membranes permeabilization and other functional segments play a vital role to modulate the pathological effects of PrP-medicated neurotoxicity. This may yield essential insights into molecular mechanisms of prion neurotoxicity to cellular membranes in prion disease.

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A Promising Antiprion Trimethoxychalcone Binds to the Globular Domain of the Cellular Prion Protein and Changes Its Cellular Location

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01441-17 ◽

2017 ◽

Vol 62 (2) ◽

Cited By ~ 6

Author(s):

N. C. Ferreira ◽

L. M. Ascari ◽

A. G. Hughson ◽

G. R. Cavalheiro ◽

C. F. Góes ◽

...

Keyword(s):

Cell Surface ◽

Real Time ◽

Prion Protein ◽

Molecular Mechanisms ◽

Cellular Prion Protein ◽

Transmissible Spongiform Encephalopathies ◽

Globular Domain ◽

Mrna Levels ◽

Spongiform Encephalopathies

ABSTRACTThe 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 identifiedin vitroto be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrPCmRNA 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 PrPScseeds 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 PrPCglobular domain. J8 also reduced the fibrillation of mouse rPrP23–231seeded within vitro-produced fibrils. Furthermore, most of the compounds decreased the amount of PrPCon 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 PrPCcontent on the cell surface.

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Cellular and Molecular Mechanisms of Prion Disease

Annual Review of Pathology Mechanisms of Disease ◽

10.1146/annurev-pathmechdis-012418-013109 ◽

2019 ◽

Vol 14 (1) ◽

pp. 497-516 ◽

Cited By ~ 15

Author(s):

Christina J. Sigurdson ◽

Jason C. Bartz ◽

Markus Glatzel

Keyword(s):

Prion Protein ◽

Prion Disease ◽

Molecular Mechanisms ◽

Prion Diseases ◽

Neuronal Loss ◽

Cellular Prion Protein ◽

Future Research ◽

Spongiform Encephalopathy ◽

Disease Epidemics ◽

Infectious Proteins

Prion diseases are rapidly progressive, incurable neurodegenerative disorders caused by misfolded, aggregated proteins known as prions, which are uniquely infectious. Remarkably, these infectious proteins have been responsible for widespread disease epidemics, including kuru in humans, bovine spongiform encephalopathy in cattle, and chronic wasting disease in cervids, the latter of which has spread across North America and recently appeared in Norway and Finland. The hallmark histopathological features include widespread spongiform encephalopathy, neuronal loss, gliosis, and deposits of variably sized aggregated prion protein, ranging from small, soluble oligomers to long, thin, unbranched fibrils, depending on the disease. Here, we explore recent advances in prion disease research, from the function of the cellular prion protein to the dysfunction triggering neurotoxicity, as well as mechanisms underlying prion spread between cells. We also highlight key findings that have revealed new therapeutic targets and consider unanswered questions for future research.

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Prion protein and prion disease at a glance

Journal of Cell Science ◽

10.1242/jcs.245605 ◽

2021 ◽

Vol 134 (17) ◽

Author(s):

Caihong Zhu ◽

Adriano Aguzzi

Keyword(s):

Prion Protein ◽

Prion Disease ◽

Neurodegenerative Disorders ◽

Prion Diseases ◽

Amyloid Β ◽

Cellular Prion Protein ◽

Future Studies ◽

Associated Proteins ◽

Main Component ◽

Conformational Conversion

ABSTRACT Prion diseases are neurodegenerative disorders caused by conformational conversion of the cellular prion protein (PrPC) into scrapie prion protein (PrPSc). As the main component of prion, PrPSc acts as an infectious template that recruits and converts normal cellular PrPC into its pathogenic, misfolded isoform. Intriguingly, the phenomenon of prionoid, or prion-like, spread has also been observed in many other disease-associated proteins, such as amyloid β (Aβ), tau and α-synuclein. This Cell Science at a Glance and the accompanying poster highlight recently described physiological roles of prion protein and the advanced understanding of pathogenesis of prion disease they have afforded. Importantly, prion protein may also be involved in the pathogenesis of other neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Therapeutic studies of prion disease have also exploited novel strategies to combat these devastating diseases. Future studies on prion protein and prion disease will deepen our understanding of the pathogenesis of a broad spectrum of neurodegenerative conditions.

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The structural transformation comparison of the human Prion protein mutants V176G, E196A, and I215V by using molecular dynamics simulation

10.21203/rs.3.rs-256266/v1 ◽

2021 ◽

Author(s):

Ashraf Fadhil Jomah ◽

Sepideh Parvizpour ◽

Jafar Razmara ◽

Mohd Shahir Shamsir

Keyword(s):

Prion Protein ◽

Aqueous Media ◽

Point Mutations ◽

Cellular Prion Protein ◽

Dynamics Simulation ◽

Globular Domain ◽

Salt Bridges ◽

Wild Type ◽

Structural Determinants ◽

C Terminus

Abstract The point mutations in the gene coding of prion protein (PrP) originate human familial prion protein (HuPrP) diseases. Such diseases are caused by several amino acid mutations of HuPrP including V176G, I215V, and E196A located at the second, third native helix and in their loop, respectively. Determining the transition from cellular prion protein (PrPc) to pathogenic conformer (PrPSc) in the globular domain of HuPrP that results in pathogenic mutations is the key issue. The effects of mutation on monomeric PrP are detected in the absence of an unstructured N-terminal domain only. A MD simulation for each of these wild type mutants is performed to examine their structure in the aqueous media. The structural determinants are discerned to be different for wild-type HuPrP (125–228) variants compare to that of HuPrP mutations. These three mutations exhibiting diverse effects on the dynamical properties of PrP are attributed to the variations in the secondary structure, solvent accessible surface areas (SASAs), and salt bridges in the globular domain of HuPrP. High fluctuations that are evidenced around residues of the C-terminus of the helix 1 for V176G cause Gerstmann-Straussler-Scheinker (GSS) syndrome. Conversely, the occurrence of fluctuations around residues of helix 2, helix 3, and the loss of salt bridges in these regions for E196A and I215V mutants is responsible for Creutzfeldt-Jakob disease. Furthermore, small changes in the overall SASAs mutations strongly influence the intermolecular interactions during the aggregation process. The comparative results in this study demonstrate that the three mutants undergo different pathogenic transformations.

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PrP glycoforms are associated in a strain-specific ratio in native PrPSc

Journal of General Virology ◽

10.1099/vir.0.80375-0 ◽

2005 ◽

Vol 86 (9) ◽

pp. 2635-2644 ◽

Cited By ~ 45

Author(s):

Azadeh Khalili-Shirazi ◽

Linda Summers ◽

Jacqueline Linehan ◽

Gary Mallinson ◽

David Anstee ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Prion Protein ◽

Prion Disease ◽

Prion Diseases ◽

Cellular Prion Protein ◽

Normal Brain ◽

Western Blots ◽

Prion Strains ◽

Specific Manner ◽

First Time

Prion diseases involve conversion of host-encoded cellular prion protein (PrPC) to a disease-related isoform (PrPSc). Using recombinant human β-PrP, a panel of monoclonal antibodies was produced that efficiently immunoprecipitated native PrPSc and recognized epitopes between residues 93–105, indicating for the first time that this region is exposed in both human vCJD and mouse RML prions. In contrast, monoclonal antibodies raised to human α-PrP were more efficient in immunoprecipitating PrPC than PrPSc, and some of them could also distinguish between different PrP glycoforms. Using these monoclonal antibodies, the physical association of PrP glycoforms was studied in normal brain and in the brains of humans and mice with prion disease. It was shown that while PrPC glycoforms can be selectively immunoprecipitated, the differentially glycosylated molecules of native PrPSc are closely associated and always immunoprecipitate together. Furthermore, the ratio of glycoforms comprising immunoprecipitated native PrPSc from diverse prion strains was similar to those observed on denaturing Western blots. These studies are consistent with the view that the proportion of each glycoform incorporated into PrPSc is probably controlled in a strain-specific manner and that each PrPSc particle contains a mixture of glycoforms.

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Cytosolic Prion Protein Toxicity Is Independent of Cellular Prion Protein Expression and Prion Propagation

Journal of Virology ◽

10.1128/jvi.02157-06 ◽

2006 ◽

Vol 81 (6) ◽

pp. 2831-2837 ◽

Cited By ~ 13

Author(s):

Eric M. Norstrom ◽

Mark F. Ciaccio ◽

Benjamin Rassbach ◽

Robert Wollmann ◽

James A. Mastrianni

Keyword(s):

Prion Protein ◽

Prion Disease ◽

Cultured Cells ◽

Prion Diseases ◽

Cerebellar Atrophy ◽

Cellular Prion Protein ◽

Cellular Toxicity ◽

Prion Propagation ◽

Gait Abnormalities ◽

Protein Toxicity

ABSTRACT Prion diseases are transmissible neurodegenerative diseases caused by a conformational isoform of the prion protein (PrP), a host-encoded cell surface sialoglycoprotein. Recent evidence suggests a cytosolic fraction of PrP (cyPrP) functions either as an initiating factor or toxic element of prion disease. When expressed in cultured cells, cyPrP acquires properties of the infectious conformation of PrP (PrPSc), including insolubility, protease resistance, aggregation, and toxicity. Transgenic mice (2D1 and 1D4 lines) that coexpress cyPrP and PrPC exhibit focal cerebellar atrophy, scratching behavior, and gait abnormalities suggestive of prion disease, although they lack protease-resistant PrP. To determine if the coexpression of PrPC is necessary or inhibitory to the phenotype of these mice, we crossed Tg1D4(Prnp +/+ ) mice with PrP-ablated mice (TgPrnp o/o) to generate Tg1D4(Prnp o/o) mice and followed the development of disease and pathological phenotype. We found no difference in the onset of symptoms or the clinical or pathological phenotype of disease between Tg1D4(Prnp +/+ ) and Tg1D4(Prnp o/o) mice, suggesting that cyPrP and PrPC function independently in the disease state. Additionally, Tg1D4(Prnp o/o) mice were resistant to challenge with mouse-adapted scrapie (RML), suggesting cyPrP is inaccessible to PrPSc. We conclude that disease phenotype and cellular toxicity associated with the expression of cyPrP are independent of PrPC and the generation of typical prion disease.

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The Quest for Cellular Prion Protein Functions in the Aged and Neurodegenerating Brain

Cells ◽

10.3390/cells9030591 ◽

2020 ◽

Vol 9 (3) ◽

pp. 591 ◽

Cited By ~ 1

Author(s):

Rosalina Gavín ◽

Laia Lidón ◽

Isidre Ferrer ◽

José Antonio del Río

Keyword(s):

Prion Protein ◽

Scientific Community ◽

Molecular Mechanisms ◽

Cellular Prion Protein ◽

Pathogenic Role ◽

Knock Out ◽

Protein Functions ◽

A Cell ◽

Knock Out Mice ◽

Vast Range

Cellular (also termed ‘natural’) prion protein has been extensively studied for many years for its pathogenic role in prionopathies after misfolding. However, neuroprotective properties of the protein have been demonstrated under various scenarios. In this line, the involvement of the cellular prion protein in neurodegenerative diseases other than prionopathies continues to be widely debated by the scientific community. In fact, studies on knock-out mice show a vast range of physiological functions for the protein that can be supported by its ability as a cell surface scaffold protein. In this review, we first summarize the most commonly described roles of cellular prion protein in neuroprotection, including antioxidant and antiapoptotic activities and modulation of glutamate receptors. Second, in light of recently described interaction between cellular prion protein and some amyloid misfolded proteins, we will also discuss the molecular mechanisms potentially involved in protection against neurodegeneration in pathologies such as Alzheimer’s, Parkinson’s, and Huntington’s diseases.

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Liquid-liquid phase separation and aggregation of the prion protein globular domain modulated by a high-affinity DNA aptamer

10.1101/659037 ◽

2019 ◽

Cited By ~ 1

Author(s):

Carolina O. Matos ◽

Yulli M. Passos ◽

Mariana J. do Amaral ◽

Bruno Macedo ◽

Matheus Tempone ◽

...

Keyword(s):

Phase Separation ◽

Liquid Phase ◽

Prion Protein ◽

Liquid Phase Separation ◽

Cellular Prion Protein ◽

Globular Domain ◽

Structural Conversion ◽

High Affinity ◽

Liquid Liquid Phase Separation

ABSTRACTStructural conversion of cellular prion protein (PrPC) into scrapie PrP (PrPSc) and subsequent aggregation are key events for the onset of Transmissible Spongiform Encephalopathies (TSEs). Experimental evidences support the role of nucleic acids (NAs) in assisting the protein conversion process. Here, we used the SELEX methodology to identify two 25-mer DNA aptamers against the globular domain of recombinant murine PrP (rPrP90-231), namely A1 and A2. High-affinity binding of A1 and A2 to rPrP was verified by ITC. Aptamers structure was characterized by theoretical predictions, CD, NMR and SAXS, revealing that A1 adopts a hairpin conformation. Aptamer binding caused dynamic aggregation of rPrP90-231, resulting from the ability of rPrP90-231to undergo liquid-liquid phase separation (LLPS). While free rPrP90-231phase separated into large droplets, aptamer binding increased the amount but reduced the size of the condensates. Strikingly, a modified A1 aptamer that does not adopt a hairpin structure induced transition to an ordered state, suggestive of amyloid formation on the surface of the droplets. Our results describe for the first time PrP:NA interaction leading to LLPS and modulation of this effect depending on NA structure and binding stoichiometry, shedding light on the role of NAs in PrP misfolding and TSEs.

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Manganese Upregulates Cellular Prion Protein and Contributes to Altered Stabilization and Proteolysis: Relevance to Role of Metals in Pathogenesis of Prion Disease

Toxicological Sciences ◽

10.1093/toxsci/kfq049 ◽

2010 ◽

Vol 115 (2) ◽

pp. 535-546 ◽

Cited By ~ 32

Author(s):

Christopher J. Choi ◽

Vellareddy Anantharam ◽

Dustin P. Martin ◽

Eric M. Nicholson ◽

Jürgen A. Richt ◽

...

Keyword(s):

Prion Protein ◽

Prion Disease ◽

Cellular Prion Protein

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Novel quaternary structures of the human prion protein globular domain

10.1101/2020.11.16.385856 ◽

2020 ◽

Author(s):

Leandro Oliveira Bortot ◽

Victor Lopes Rangel ◽

Francesca A. Pavlovici ◽

Kamel El Omari ◽

Armin Wagner ◽

...

Keyword(s):

Drug Discovery ◽

Prion Protein ◽

3D Structure ◽

Disulfide Bridge ◽

Cellular Prion Protein ◽

Crystallographic Structure ◽

Globular Domain ◽

X Ray Crystallography ◽

Quaternary Structures ◽

Dynamics Simulations

AbstractPrion 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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