scholarly journals Conformational conversion of prion protein in prion diseases

2013 ◽  
Vol 45 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Z. Zhou ◽  
G. Xiao
2021 ◽  
Vol 134 (17) ◽  
Author(s):  
Caihong Zhu ◽  
Adriano Aguzzi

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.


2017 ◽  
Vol 92 (1) ◽  
Author(s):  
Hideyuki Hara ◽  
Hironori Miyata ◽  
Nandita Rani Das ◽  
Junji Chida ◽  
Tatenobu Yoshimochi ◽  
...  

ABSTRACTConformational conversion of the cellular isoform of prion protein, PrPC, into the abnormally folded, amyloidogenic isoform, PrPSc, is a key pathogenic event in prion diseases, including Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy (BSE) in animals. We previously reported that the octapeptide repeat (OR) region could be dispensable for converting PrPCinto PrPScafter infection with RML prions. We demonstrated that mice transgenically expressing mouse PrP with deletion of the OR region on the PrP knockout background, designated Tg(PrPΔOR)/Prnp0/0mice, did not show reduced susceptibility to RML scrapie prions, with abundant accumulation of PrPScΔOR in their brains. We show here that Tg(PrPΔOR)/Prnp0/0mice were highly resistant to BSE prions, developing the disease with markedly elongated incubation times after infection with BSE prions. The conversion of PrPΔOR into PrPScΔOR was markedly delayed in their brains. These results suggest that the OR region may have a crucial role in the conversion of PrPCinto PrPScafter infection with BSE prions. However, Tg(PrPΔOR)/Prnp0/0mice remained susceptible to RML and 22L scrapie prions, developing the disease without elongated incubation times after infection with RML and 22L prions. PrPScΔOR accumulated only slightly less in the brains of RML- or 22L-infected Tg(PrPΔOR)/Prnp0/0mice than PrPScin control wild-type mice. Taken together, these results indicate that the OR region of PrPCcould play a differential role in the pathogenesis of BSE prions and RML or 22L scrapie prions.IMPORTANCEStructure-function relationship studies of PrPCconformational conversion into PrPScare worthwhile to understand the mechanism of the conversion of PrPCinto PrPSc. We show here that, by inoculating Tg(PrPΔOR)/Prnp0/0mice with the three different strains of RML, 22L, and BSE prions, the OR region could play a differential role in the conversion of PrPCinto PrPScafter infection with RML or 22L scrapie prions and BSE prions. PrPΔOR was efficiently converted into PrPScΔOR after infection with RML and 22L prions. However, the conversion of PrPΔOR into PrPScΔOR was markedly delayed after infection with BSE prions. Further investigation into the role of the OR region in the conversion of PrPCinto PrPScafter infection with BSE prions might be helpful for understanding the pathogenesis of BSE prions.


2021 ◽  
Vol 22 (21) ◽  
pp. 11742
Author(s):  
Keiji Uchiyama ◽  
Hideyuki Hara ◽  
Junji Chida ◽  
Agriani Dini Pasiana ◽  
Morikazu Imamura ◽  
...  

Prion diseases are a group of fatal neurodegenerative disorders caused by accumulation of proteinaceous infectious particles, or prions, which mainly consist of the abnormally folded, amyloidogenic prion protein, designated PrPSc. PrPSc is produced through conformational conversion of the cellular isoform of prion protein, PrPC, in the brain. To date, no effective therapies for prion diseases have been developed. In this study, we incidentally noticed that mouse neuroblastoma N2a cells persistently infected with 22L scrapie prions, termed N2aC24L1-3 cells, reduced PrPSc levels when cultured in advanced Dulbecco’s modified eagle medium (DMEM) but not in classic DMEM. PrPC levels remained unchanged in prion-uninfected parent N2aC24 cells cultured in advanced DMEM. These results suggest that advanced DMEM may contain an anti-prion compound(s). We then successfully identified ethanolamine in advanced DMEM has an anti-prion activity. Ethanolamine reduced PrPSc levels in N2aC24L1-3 cells, but not PrPC levels in N2aC24 cells. Also, oral administration of ethanolamine through drinking water delayed prion disease in mice intracerebrally inoculated with RML scrapie prions. These results suggest that ethanolamine could be a new anti-prion compound.


Author(s):  
Meilan Zhang ◽  
Haoran Zhang ◽  
Hongwei Yao ◽  
Chenyun Guo ◽  
Donghai Lin

Abstract The pathogenesis of fatal neurodegenerative prion diseases is closely associated with the conversion of α-helix-rich cellular prion protein into β-sheet-rich scrapie form. Pathogenic point mutations of prion proteins usually promote the conformational conversion and trigger inherited prion diseases. The G131V mutation of human prion protein (HuPrP) was identified to be involved in Gerstmann–Sträussler–Scheinker syndrome. Few studies have been carried out to address the pathogenesis of the G131V mutant. Here, we addressed the effects of the G131V mutation on oligomerization and fibrillization of the full-length HuPrP(23–231) and truncated HuPrP(91–231) proteins. The G131V mutation promotes the oligomerization but alleviates the fibrillization of HuPrP, implying that the oligomerization might play a crucial role in the pathogenic mechanisms of the G131V mutant. Moreover, the flexible N-terminal fragment in either the wild-type or the G131V mutant HuPrP increases the oligomerization tendencies but decreases the fibrillization tendencies. Furthermore, this mutation significantly alters the tertiary structure of human PrPC and might distinctly change the conformational conversion tendency. Interestingly, both guanidine hydrochloride denaturation and thermal denaturation experiments showed that the G131V mutation does not significantly change the thermodynamic stabilities of the HuPrP proteins. This work may be of benefit to a mechanistic understanding of the conformational conversion of prion proteins and also provide clues for the prevention and treatment of prion diseases.


2004 ◽  
Vol 36 (2) ◽  
pp. 128-132
Author(s):  
Shao-Man Yin ◽  
Man-Sun Sy ◽  
Po Tien

Abstract Production of the pathogenic prion isoform PrPsc-like molecules is thought to be useful for understanding the mysterious mechanism of conformational conversion process of prion diseases and proving the “protein-only” hypothesis. In this report, an engineered PrPsc-like conformation was produced from a chimera of mammalian bovine prion protein (bPrP) and yeast Ure2p prion-inducing domain (UPrD). Compared with the normal form of bPrP, the engineered recombinant protein, termed bPrP-UPrD, spontaneously aggregated into ordered fibrils under physiological condition, displaying amyloid-like characteristics, such as fibrillar morphology, birefringence upon binding to Congo red and increased fluorescence intensity with Thioflavine T. Limited resistance to protease K digestion and CD spectroscopy experiments suggested that the structure of bPrP-UPrD had been changed, and adopted a new, high content β-sheet conformation during the fibrils formation. Moreover, bPrP-UPrD amyloid fibrils could recruit more soluble forms into the aggregates. Therefore, the engineered molecules could mimic significant behaviors of PrPsc and will be helpful for further understanding the mechanism of conformational conversion process.


2021 ◽  
Vol 22 (3) ◽  
pp. 1267
Author(s):  
Masahiro Kawahara ◽  
Midori Kato-Negishi ◽  
Ken-ichiro Tanaka

Prion diseases are progressive and transmissive neurodegenerative diseases. The conformational conversion of normal cellular prion protein (PrPC) into abnormal pathogenic prion protein (PrPSc) is critical for its infection and pathogenesis. PrPC possesses the ability to bind to various neurometals, including copper, zinc, iron, and manganese. Moreover, increasing evidence suggests that PrPC plays essential roles in the maintenance of homeostasis of these neurometals in the synapse. In addition, trace metals are critical determinants of the conformational change and toxicity of PrPC. Here, we review our studies and other new findings that inform the current understanding of the links between trace elements and physiological functions of PrPC and the neurotoxicity of PrPSc.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Giovanni Spagnolli ◽  
Tania Massignan ◽  
Andrea Astolfi ◽  
Silvia Biggi ◽  
Marta Rigoli ◽  
...  

AbstractRecent computational advancements in the simulation of biochemical processes allow investigating the mechanisms involved in protein regulation with realistic physics-based models, at an atomistic level of resolution. These techniques allowed us to design a drug discovery approach, named Pharmacological Protein Inactivation by Folding Intermediate Targeting (PPI-FIT), based on the rationale of negatively regulating protein levels by targeting folding intermediates. Here, PPI-FIT was tested for the first time on the cellular prion protein (PrP), a cell surface glycoprotein playing a key role in fatal and transmissible neurodegenerative pathologies known as prion diseases. We predicted the all-atom structure of an intermediate appearing along the folding pathway of PrP and identified four different small molecule ligands for this conformer, all capable of selectively lowering the load of the protein by promoting its degradation. Our data support the notion that the level of target proteins could be modulated by acting on their folding pathways, implying a previously unappreciated role for folding intermediates in the biological regulation of protein expression.


2021 ◽  
Vol 22 (10) ◽  
pp. 5075
Author(s):  
Mantas Ziaunys ◽  
Andrius Sakalauskas ◽  
Kamile Mikalauskaite ◽  
Ruta Snieckute ◽  
Vytautas Smirnovas

Prion protein aggregation into amyloid fibrils is associated with the onset and progression of prion diseases—a group of neurodegenerative amyloidoses. The process of such aggregate formation is still not fully understood, especially regarding their polymorphism, an event where the same type of protein forms multiple, conformationally and morphologically distinct structures. Considering that such structural variations can greatly complicate the search for potential antiamyloid compounds, either by having specific propagation properties or stability, it is important to better understand this aggregation event. We have recently reported the ability of prion protein fibrils to obtain at least two distinct conformations under identical conditions, which raised the question if this occurrence is tied to only certain environmental conditions. In this work, we examined a large sample size of prion protein aggregation reactions under a range of temperatures and analyzed the resulting fibril dye-binding, secondary structure and morphological properties. We show that all temperature conditions lead to the formation of more than one fibril type and that this variability may depend on the state of the initial prion protein molecules.


2021 ◽  
Vol 15 (1) ◽  
pp. 193-196
Author(s):  
Máximo Sanz-Hernández ◽  
Alfonso De Simone

AbstractTransmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative disorders associated with the misfolding and aggregation of the human prion protein (huPrP). Despite efforts into investigating the process of huPrP aggregation, the mechanisms triggering its misfolding remain elusive. A number of TSE-associated mutations of huPrP have been identified, but their role at the onset and progression of prion diseases is unclear. Here we report the NMR assignments of the C-terminal globular domain of the wild type huPrP and the pathological mutant T183A. The differences in chemical shifts between the two variants reveal conformational alterations in some structural elements of the mutant, whereas the analyses of secondary shifts and random coil index provide indications on the putative mechanisms of misfolding of T183A huPrP.


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