1
|
Shiraishi N, Hirano Y. Combination of Copper Ions and Nucleotide Generates Aggregates from Prion Protein Fragments in the N-Terminal Domain. Protein Pept Lett 2021; 27:782-792. [PMID: 32096738 DOI: 10.2174/0929866527666200225124829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND It has been previously found that PrP23-98, which contains four highly conserved octarepeats (residues 60-91) and one partial repeat (residues 92-96), polymerizes into amyloid-like and proteinase K-resistant spherical aggregates in the presence of NADPH plus copper ions. OBJECTIVE We aimed to determine the requirements for the formation of these aggregates. METHODS In this study, we performed an aggregation experiment using N-acetylated and Camidated PrP fragments of the N-terminal domain, Octa1, Octa2, Octa3, Octa4, PrP84-114, and PrP76-114, in the presence of NADPH with copper ions, and focused on the effect of the number of copper-binding sites on aggregation. RESULTS Among these PrP fragments, Octa4, containing four copper-binding sites, was particularly effective in forming aggregates. We also tested the effect of other pyridine nucleotides and adenine nucleotides on the aggregation of Octa4. ATP was equally effective, but NADH, NADP, ADP, and AMP had no effect. CONCLUSION The phosphate group on the adenine-linked ribose moiety of adenine nucleotides and pyridine nucleotides is presumed to be essential for the observed effect on aggregation. Efficient aggregation requires the presence of the four octarepeats. These insights may be helpful in the eventual development of therapeutic agents against prion-related disorders.
Collapse
Affiliation(s)
- Noriyuki Shiraishi
- Department of Nutrition, Tokai Gakuen University, 2-901 Nakahira, Nagoya 468-8514, Japan
| | - Yoshiaki Hirano
- Department of Nutrition, Tokai Gakuen University, 2-901 Nakahira, Nagoya 468-8514, Japan
| |
Collapse
|
2
|
Bose S, Cho J. Targeting chaperones, heat shock factor-1, and unfolded protein response: Promising therapeutic approaches for neurodegenerative disorders. Ageing Res Rev 2017; 35:155-175. [PMID: 27702699 DOI: 10.1016/j.arr.2016.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/02/2016] [Accepted: 09/26/2016] [Indexed: 12/22/2022]
Abstract
Protein misfolding, which is known to cause several serious diseases, is an emerging field that addresses multiple therapeutic areas. Misfolding of a disease-specific protein in the central nervous system ultimately results in the formation of toxic aggregates that may accumulate in the brain, leading to neuronal cell death and dysfunction, and associated clinical manifestations. A large number of neurodegenerative diseases in humans, including Alzheimer's, Parkinson's, Huntington's, and prion diseases, are primarily caused by protein misfolding and aggregation. Notably, the cellular system is equipped with a protein quality control system encompassing chaperones, ubiquitin proteasome system, and autophagy, as a defense mechanism that monitors protein folding and eliminates inappropriately folded proteins. As the intrinsic molecular mechanisms of protein misfolding become more clearly understood, the novel therapeutic approaches in this arena are gaining considerable interest. The present review will describe the chaperones network and different approaches as the therapeutic targets for neurodegenerative diseases. Current and emerging therapeutic approaches to combat neurodegenerative diseases, addressing the roles of molecular, chemical, and pharmacological chaperones, as well as heat shock factor-1 and the unfolded protein response, are also discussed in detail.
Collapse
Affiliation(s)
- Shambhunath Bose
- College of Pharmacy, Dongguk University-Seoul, Goyang, Gyeonggi-do 10326, Republic of Korea
| | - Jungsook Cho
- College of Pharmacy, Dongguk University-Seoul, Goyang, Gyeonggi-do 10326, Republic of Korea.
| |
Collapse
|
3
|
Molecular chaperone dysfunction in neurodegenerative diseases and effects of curcumin. BIOMED RESEARCH INTERNATIONAL 2014; 2014:495091. [PMID: 25386560 PMCID: PMC4217372 DOI: 10.1155/2014/495091] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/23/2014] [Indexed: 01/26/2023]
Abstract
The intra- and extracellular accumulation of misfolded and aggregated amyloid proteins is a common feature in several neurodegenerative diseases, which is thought to play a major role in disease severity and progression. The principal machineries maintaining proteostasis are the ubiquitin proteasomal and lysosomal autophagy systems, where heat shock proteins play a crucial role. Many protein aggregates are degraded by the lysosomes, depending on aggregate size, peptide sequence, and degree of misfolding, while others are selectively tagged for removal by heat shock proteins and degraded by either the proteasome or phagosomes. These systems are compromised in different neurodegenerative diseases. Therefore, developing novel targets and classes of therapeutic drugs, which can reduce aggregates and maintain proteostasis in the brains of neurodegenerative models, is vital. Natural products that can modulate heat shock proteins/proteosomal pathway are considered promising for treating neurodegenerative diseases. Here we discuss the current knowledge on the role of HSPs in protein misfolding diseases and knowledge gained from animal models of Alzheimer's disease, tauopathies, and Huntington's diseases. Further, we discuss the emerging treatment regimens for these diseases using natural products, like curcumin, which can augment expression or function of heat shock proteins in the cell.
Collapse
|
4
|
Abstract
Creutzfeldt-Jakob Disease (CJD) is considered to be a sudden and fatal degenerative brain disorder that leads to death within a few months. In the last decade, we have studied the course of familial CJD (fCJD) among Jews of Libyan descent, one of the largest clusters of fCJD in the world. Recently, we published results that included the identification of abnormal anxiety levels in healthy CJD E200K mutation carriers that were significantly different from those of healthy non-carriers from the same families. All participants were first-degree relatives of patients known to have been carriers of the E200K mutation and had died from CJD, and none of the participants was aware of his/her genetic make-up. In the current review, it is suggested that an abnormality in anxiety levels among the healthy fCJD mutation carriers may reflect the clinical presentation of the disease onset especially during and after any stressful experience. This hypothesis is supported by a summary of relevant literature, dealing with psychological, physiological, and cellular aspects.
Collapse
Affiliation(s)
- Ariela Gigi
- Department of Behavioral Sciences, Ariel University Center, Ariel, Israel.
| |
Collapse
|
5
|
Lechauve C, Rezaei H, Celier C, Kiger L, Corral-Debrinski M, Noinville S, Chauvierre C, Hamdane D, Pato C, Marden MC. Neuroglobin and prion cellular localization: investigation of a potential interaction. J Mol Biol 2009; 388:968-77. [PMID: 19327369 DOI: 10.1016/j.jmb.2009.03.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 02/18/2009] [Accepted: 03/18/2009] [Indexed: 11/25/2022]
Abstract
Neuroglobin (Ngb) and the cellular prion protein (PrP(c)), proteins of unknown function in the nervous system, are known to be expressed in the retina and have been observed in different rat retinal cells. The retina is the site of the highest concentration for Ngb, a heme protein of similar size and conformation to myoglobin. In this study, we demonstrated by immunohistochemical analysis of retinal colocalization of Ngb and PrP(c) in the ganglion cell layer. Considering for these two a common protective role in relation to oxidative stress and a possible transient contact during migration of PrP(c) through the eye or upon neuronal degradation, we undertook in vitro studies of the interaction of the purified proteins. Mixing these two proteins leads to rapid aggregation, even at submicromolar concentrations. As observed with the use of dynamic light scattering, particles comprising both proteins evolve to hundreds of nanometers within several seconds, a first report showing that PrP(c) is able to form aggregates without major structural changes. The main effect would then appear to be a protein-protein interaction specific to the surface charge of the Ngb protein with PrP(c) N-terminal sequence. A dominant parameter is the solvent ionic force, which can significantly modify the final state of aggregation. PrP(c), normally anchored to the cell membrane, is toxic in the cytoplasm, where Ngb is present; this could suggest an Ngb function of scavenging proteins capable of forming deleterious aggregates considering a charge complementarity in the complex.
Collapse
Affiliation(s)
- Christophe Lechauve
- INSERM U779, Universités Paris VI et XI, Hopital de Bicêtre, Le Kremlin-Bicêtre, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Liang J, Pan Y, Zhang D, Guo C, Shi Y, Wang J, Chen Y, Wang X, Liu J, Guo X, Chen Z, Qiao T, Fan D. Cellular prion protein promotes proliferation and G1/S transition of human gastric cancer cells SGC7901 and AGS. FASEB J 2007; 21:2247-56. [PMID: 17409275 DOI: 10.1096/fj.06-7799com] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The function of cellular prion protein (PrP(C)), the essential protein for the pathogenesis and transmission of prion diseases, is still largely unknown. The putative roles of PrP(C) are thought to be related to cell signaling, survival, and differentiation. In a previous study, we showed that PrP(C) was overexpressed in gastric cancer tissues. In the present report, we show that ectopic expression of PrP(C) could promote tumorigenesis, proliferation, and G1/S transition in gastric cancer cells. Furthermore, CyclinD1, a protein related to cell cycle, was shown to be significantly up-regulated by PrP(C) at both mRNA and protein levels. PI3K/Akt pathway mediated above PrP(C) signal since PrP(C) increased the expression of phosphorylated Akt, and the specific inhibitor of Akt, LY294002, could markedly suppress growth of SGC7901 and transactivation of CyclinD1 induced by PrP(C). Octapeptide repeat region played a vital role in this function, as deletion of this region abolished or reduced these effects. Collectively, this study demonstrates that overexpression of PrP(C) might promote the tumorigenesis and proliferation of gastric cancer cells at least partially through activation of PI3K/Akt pathway and subsequent transcriptional activation of CyclinD1 to regulate the G1/S phase transition, in which octapeptide repeat region might be an indispensable region.
Collapse
MESH Headings
- Animals
- Cell Division/drug effects
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Chromones/pharmacology
- Cyclin D
- Cyclins/biosynthesis
- Cyclins/genetics
- Cyclins/physiology
- G1 Phase
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Morpholines/pharmacology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Neoplasm Transplantation
- Phosphatidylinositol 3-Kinases/physiology
- PrPC Proteins/chemistry
- PrPC Proteins/genetics
- PrPC Proteins/physiology
- Proto-Oncogene Proteins c-akt/antagonists & inhibitors
- Proto-Oncogene Proteins c-akt/physiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Recombinant Fusion Proteins/physiology
- Repetitive Sequences, Amino Acid
- S Phase
- Sequence Deletion
- Signal Transduction/genetics
- Signal Transduction/physiology
- Stomach Neoplasms/genetics
- Stomach Neoplasms/pathology
- Transcriptional Activation/drug effects
- Transfection
- Tumor Stem Cell Assay
Collapse
Affiliation(s)
- Jie Liang
- State Key Laboratory of Cancer Biology, Xijing Hospital, Fourth Military Medical University, 15 West Chang-Le Rd., Xi'an, Shaanxi Province, China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Shiraishi N, Utsunomiya H, Nishikimi M. Combination of NADPH and copper ions generates proteinase K-resistant aggregates from recombinant prion protein. J Biol Chem 2006; 281:34880-7. [PMID: 16990274 DOI: 10.1074/jbc.m606581200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies have demonstrated that the octapeptide repeats of the N-terminal region of prion protein may be responsible for de novo generation of infectious prions in the absence of template. Here we demonstrate that PrP-(23-98), an N-terminal portion of PrP, is converted to aggregates upon incubation with NADPH and copper ions. Other pyridine nucleotides possessing a phosphate group on the adenine-linked ribose moiety (the reduced form of nicotinamide adenine dinucleotide 3'-phosphate, nicotinic acid adenine dinucleotide phosphate, and NADP) were also effective in promoting aggregation, but NADH and NAD had no effect. The aggregation was attenuated by the metal chelator EDTA or by modification of histidyl residues with diethyl pyrocarbonate. The aggregates are amyloid-like as judged by the binding of thioflavin T, a fluorescent probe for amyloid, but do not exhibit fibrillar structures according to electron micrography. Interestingly the aggregates were resistant to proteinase K digestion. Likewise NADPH and zinc ions caused aggregation of PrP-(23-98), but the resulting aggregates were susceptible to degradation by proteinase K. Upon incubation with NADPH and copper ions, the full-length molecule PrP-(23-231) also formed proteinase K-resistant amyloid-like aggregates. Because it is possible that PrP, NADPH, and copper ions could associate in certain tissues, the aggregation observed in this study may be involved in prion initiation especially in the nonfamilial types of prion diseases.
Collapse
Affiliation(s)
- Noriyuki Shiraishi
- Department of Biochemistry and Central Research Laboratory, Wakayama Medical University, Wakayama 641-8509, Japan.
| | | | | |
Collapse
|
8
|
Jemth P, Day R, Gianni S, Khan F, Allen M, Daggett V, Fersht AR. The Structure of the Major Transition State for Folding of an FF Domain from Experiment and Simulation. J Mol Biol 2005; 350:363-78. [PMID: 15935381 DOI: 10.1016/j.jmb.2005.04.067] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 04/26/2005] [Accepted: 04/27/2005] [Indexed: 11/26/2022]
Abstract
We have analysed the transition state of folding of the four-helix FF domain from HYPA/FBP11 by high-resolution experiment and simulation as part of a continuing effort to understand the principles of folding and the refinement of predictive methods. The major transition state for folding was subjected to a Phi-value analysis utilising 50 mutants. The transition state contained a nucleus for folding centred around the end of helix 1 (H1) and the beginning of helix 2 (H2). Secondary structure in this region was fully formed (PhiF=0.9-1) and tertiary interactions were well developed. Interactions in the distal part of the native structure were weak (PhiF=0-0.2). The hydrophobic core and other parts of the protein displayed intermediate Phi-values, suggesting that interactions coalesce as the end of H1 and beginning of H2 are in the process of being formed. The distribution of Phi-values resembled that of barnase, which folds via an intermediate, rather than that of CI2 which folds by a concerted nucleation-condensation mechanism. The overall picture of the transition state structure identified in molecular dynamics simulations is in qualitative agreement, with the turn connecting H1 and H2 being formed, a loosened core, and H4 partially unfolded and detached from the core. There are some differences in the details and interpretation of specific Phi-values.
Collapse
Affiliation(s)
- Per Jemth
- MRC Centre for Protein Engineering, Hills Road, CB2 2QH Cambridge, UK
| | | | | | | | | | | | | |
Collapse
|
9
|
Zeng Q, Yin Q, Zhao Y. The study on the interaction between seryl-histidine dipeptide and proteins by circular dichroism and molecular modeling. Bioorg Med Chem 2005; 13:2679-89. [PMID: 15755667 DOI: 10.1016/j.bmc.2004.12.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Revised: 12/21/2004] [Accepted: 12/23/2004] [Indexed: 11/22/2022]
Abstract
The selective cleavage of proteins is very important in key biological processes. Chemical (nonenzymatic) reagents such as cyanogen bromide and transition metal complexes are used extensively with great defects. In this paper, the binding of seryl-histidine dipeptide (abbreviated as SH) with bovine serum albumin (BSA) and lysozyme were investigated by the circular dichroism spectroscopy (CD) at 298K, molecular docking studies and quantum chemical calculations based on the previous results of polyacrylamide gel electrophoresis (PAGE). From the studies of CD, it showed that SH interacted strongly with BSA and lysozyme. The change percentages of the secondary structures of BSA and lysozyme were calculated. The contents of the beta-sheets decreased remarkably. It indicated that the interactions between SH and proteins could break the hydrogen bonds of beta-sheets selectively. The docking studies between SH and BSA showed that the position of the oxygen atom of the hydroxyl group of SH (O(12)) was in favor of a nucleophilic attack on carbon atom of the amide bond of a beta-sheet (C(34)) because the distance between O(12) and C(34) was 3.37A. Natural charges, natural atomic hybrid percentages and square sums of HOMO coefficients calculated by the NBO and population analysis at HF/6-31G* supported the suggested mechanism. And so SH may be an interesting agent for the therapeutic use.
Collapse
Affiliation(s)
- Qing Zeng
- The Key Laboratory of Bioorganic Phosphorus Chemistry, Ministry of Education, China
| | | | | |
Collapse
|
10
|
Alonso DOV, An C, Daggett V. Simulations of biomolecules: Characterization of the early steps in the pH-induced conformational conversion of the hamster, bovine and human forms of the prion protein. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2002; 360:1165-1178. [PMID: 12804272 DOI: 10.1098/rsta.2002.0986] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
As computer power increases, so too does the range of interesting biomolecular phenomena and properties that can be simulated. It is now possible to simulate complicated protein conformational changes at ambient or physiological temperatures. In this regard, we are attempting to map the conformational transitions of the normal, cellular prion protein (PrP(C)) to its infectious scrapie isoform (PrP(Sc)), which causes neurodegenerative diseases in many mammals. These two forms have identical sequences and are conformational isomers, with heightened formation of beta-sheet structure in the scrapie form. Conversion can be triggered by lowering the pH, but thus far it has been impossible to characterize the conformational change at high resolution using experimental methods. Therefore, to investigate the effect of acidic pH on PrP conformation, we have performed molecular-dynamics simulations of hamster, human and bovine forms of the prion protein in water at neutral and low pH. In all cases the core of the protein is well maintained at neutral pH. At low pH, however, the protein is more dynamic, and the sheet-like structure increases both by lengthening of the native beta-sheet and by addition of a portion of the N-terminus to widen the sheet by another 2-3 strands.
Collapse
Affiliation(s)
- Darwin O V Alonso
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA
| | | | | |
Collapse
|
11
|
Essalmani R, Taourit S, Besnard N, Vilotte JL. Sequence determination and expression of the ovine doppel-encoding gene in transgenic mice. Gene 2002; 285:287-90. [PMID: 12039056 DOI: 10.1016/s0378-1119(02)00391-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The ovine Doppel-encoding gene transcription unit (TU) and proximal flanking regions were cloned from a bacterial artificial chromosome (BAC) and sequenced. The 4586 bp TU is composed of two exons and one intron. When compared with its human counterpart, beside the open reading frame and part of the 3' untranslated sequence, significant regions of homology were found within the intron and the proximal 5' flanking regions. Sequence analysis of the BAC clone revealed that the ovine Prnd gene is located around 52 kb downstream of the Prnp locus. Expression of the sheep and murine Prnd genes was observed in all tissues analyzed of transgenic mice bearing the BAC insert, with a noticeable highest expression level observed in the testis, with no associated noticeable phenotype. The present data suggest that, in contrast to ovine Prnp, ovine Prnd expression in transgenic mice has no obvious influence on conferred susceptibility to scrapie.
Collapse
Affiliation(s)
- Rachid Essalmani
- Laboratoire de Génétique Biochimique et de Cytogénétique, Département de Génétique Animale, Institut National de la Recherche Agronomique, 78352 Cedex, Jouy-en-Josas, France
| | | | | | | |
Collapse
|
12
|
Lu BY, Beck PJ, Chang JY. Oxidative folding of murine prion mPrP(23-231). EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3767-73. [PMID: 11432744 DOI: 10.1046/j.1432-1327.2001.02283.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A systematic study of the oxidative folding of murine prion protein mPrP(23-231) is reported here. Folding of mPrP(23-231) involves formation of a single disulfide bond, Cys179-Cys214. Despite this simplicity, reduced mPrP(23-231) exhibits numerous unusual folding properties. In the absence of denaturant, folding of mPrP(23-231) is extremely sluggish, regardless of pH. The optimal pH for mPrP(23-231) folding was found to be 4-5. At pH 8.0, a condition that typically favors disulfide formation, folding of mPrP(23-231) hardly occurs, and it not facilitated by inclusion of redox agent. In the presence of denaturant (4 M urea or 2 M guanidine hydrochloride) and basic pH (8.0), reduced mPrP(23-231) refolds to the native structure quantitatively. The efficiency of folding can be further promoted by the presence of oxidized glutathione. At pH 4.0 and in the presence of 4 M urea, reduced mPrP(23-231) converts to three distinctive conformational isomers, unable to form the native structure. These unusual properties lead us to the following conclusions. The reduced mPrP(23-231) adopts a highly rigid structure with the two cysteines buried or situated apart. The presence of denaturant or low pH disrupts this rigid structure and lowers the energy barrier, which permits oxidation and refolding of the reduced mPrP(23-231). Under selected conditions, reduced mPrP(23-231) is capable of taking on multiple forms of stable conformational isomer that are segregated by energy barriers.
Collapse
Affiliation(s)
- B Y Lu
- Research Center for Protein Chemistry, Institute of Molecular Medicine, University of Texas at Houston, Texas, USA
| | | | | |
Collapse
|
13
|
Rosenmann H, Talmor G, Halimi M, Yanai A, Gabizon R, Meiner Z. Prion protein with an E200K mutation displays properties similar to those of the cellular isoform PrP(C). J Neurochem 2001; 76:1654-62. [PMID: 11259483 DOI: 10.1046/j.1471-4159.2001.00195.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Creutzfeldt-Jakob disease (CJD) in Libyan Jews, linked to the E200K mutation in PRNP (E200KCJD), is the most prevalent of the inherited prion diseases. As other prion diseases, E200KCJD is characterized by the brain accumulation of PrP(Sc), a pathologic conformational isoform of a normal glycoprotein denominated PrP(C). To investigate whether the E200K mutation is enough to de novo confer PrP(Sc) properties to mutant PrP, as suggested by experiments in Chinese hamster ovary cells, we examined the biochemical behavior of E200KPrP in brains and fibroblasts from sporadic as well as homozygous and heterozygous E200KCJD patients, asymptomatic transgenic mice carrying the E200K mutation, as well as in normal and scrapie-infected mouse neuroblastoma cells expressing E200KPrP. E200KPrP was examined for protease sensitivity, solubility in detergents, releasibility by phosphoinositol phospholypase-C and localization in cholesterol enriched membrane microdomains (rafts). In all tissues except in brains of CJD patients and ScN2a cells, E200KPrP displayed properties similar to those of PrP(C). Our results indicate that the E200K mutation does not automatically convey the properties of PrP(Sc) to new PrP molecules. A conversion process occurs mainly in the prion disease affected brain, suggesting the presence of a tissue-specific or age-dependent factor, in accord with the late onset nature of inherited CJD.
Collapse
Affiliation(s)
- H Rosenmann
- The Agnes Ginges Center for Human Neurogenetics, Department of Neurology, Hadassah University Hospital, Jerusalem, Israel
| | | | | | | | | | | |
Collapse
|
14
|
Ramirez-Alvarado M, Merkel JS, Regan L. A systematic exploration of the influence of the protein stability on amyloid fibril formation in vitro. Proc Natl Acad Sci U S A 2000; 97:8979-84. [PMID: 10908649 PMCID: PMC16807 DOI: 10.1073/pnas.150091797] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2000] [Indexed: 11/18/2022] Open
Abstract
There are a number of diseases in which normally soluble proteins associate into regular, insoluble amyloid fibrils. The development of in vitro model systems in which detailed structural, kinetic, and thermodynamic characterization are feasible is of critical importance to our understanding of the amyloid fibril phenomenon. The formation of amyloid fibrils by proteins that are not associated with disease has been recently described, suggesting that this may be a common property of many proteins and not only of the few proteins associated with amyloidoses. The B1 Ig-binding domain of protein G (beta1) is an extremely well-characterized model system. We have found that under certain experimental conditions, some variants of beta1 form fibrils with high reproducibility. By controlling the stability of the protein-either by mutations or by changing experimental conditions-we are able to modulate the ability of the protein to form fibrils. For all of the variants, we find that the key requirement for fibril formation is to choose conditions in which the population of intermediate conformations present during the unfolding transition is maximized.
Collapse
Affiliation(s)
- M Ramirez-Alvarado
- Department of Molecular Biophysics and Biochemistry, Yale University, 266 Whitney Avenue, P.O. Box 208114, New Haven, CT 06520-8114, USA
| | | | | |
Collapse
|