1
|
Lackie RE, Marques-Lopes J, Ostapchenko VG, Good S, Choy WY, van Oosten-Hawle P, Pasternak SH, Prado VF, Prado MAM. Increased levels of Stress-inducible phosphoprotein-1 accelerates amyloid-β deposition in a mouse model of Alzheimer's disease. Acta Neuropathol Commun 2020; 8:143. [PMID: 32825842 PMCID: PMC7441634 DOI: 10.1186/s40478-020-01013-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 08/01/2020] [Indexed: 02/08/2023] Open
Abstract
Molecular chaperones and co-chaperones, which are part of the protein quality control machinery, have been shown to regulate distinct aspects of Alzheimer's Disease (AD) pathology in multiple ways. Notably, the co-chaperone STI1, which presents increased levels in AD, can protect mammalian neurons from amyloid-β toxicity in vitro and reduced STI1 levels worsen Aβ toxicity in C. elegans. However, whether increased STI1 levels can protect neurons in vivo remains unknown. We determined that overexpression of STI1 and/or Hsp90 protected C. elegans expressing Aβ(3-42) against Aβ-mediated paralysis. Mammalian neurons were also protected by elevated levels of endogenous STI1 in vitro, and this effect was mainly due to extracellular STI1. Surprisingly, in the 5xFAD mouse model of AD, by overexpressing STI1, we find increased amyloid burden, which amplifies neurotoxicity and worsens spatial memory deficits in these mutants. Increased levels of STI1 disturbed the expression of Aβ-regulating enzymes (BACE1 and MMP-2), suggesting potential mechanisms by which amyloid burden is increased in mice. Notably, we observed that STI1 accumulates in dense-core AD plaques in both 5xFAD mice and human brain tissue. Our findings suggest that elevated levels of STI1 contribute to Aβ accumulation, and that STI1 is deposited in AD plaques in mice and humans. We conclude that despite the protective effects of STI1 in C. elegans and in mammalian cultured neurons, in vivo, the predominant effect of elevated STI1 is deleterious in AD.
Collapse
Affiliation(s)
- Rachel E Lackie
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada
- Program in Neuroscience, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Canada
| | - Jose Marques-Lopes
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada
| | - Valeriy G Ostapchenko
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada
| | - Sarah Good
- School of Molecular and Cell Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Wing-Yiu Choy
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, Medical Sciences Building, 1151 Richmond St. N, London, N6A 5B7, Canada
| | - Patricija van Oosten-Hawle
- School of Molecular and Cell Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Stephen H Pasternak
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada
- St. Joseph's Health Care London-Parkwood Institute, St. Joseph's Hospital, 268 Grosvenor St Room A1-015, London, N6A 4V2, Canada
- Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, 1151 Richmond St, London, N6A 3K7, Canada
| | - Vania F Prado
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada.
- Program in Neuroscience, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Canada.
- Department of Anatomy & Cell Biology, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Canada.
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Ontario, Canada.
| | - Marco A M Prado
- Robarts Research Institute, The University of Western Ontario, 1151 Richmond St. N., London, Ontario, N6A 5B7, Canada.
- Program in Neuroscience, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Canada.
- Department of Anatomy & Cell Biology, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Canada.
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond St, London, N6A 3K7, Ontario, Canada.
| |
Collapse
|
2
|
Albatany M, Ostapchenko VG, Meakin S, Bartha R. Brain tumor acidification using drugs simultaneously targeting multiple pH regulatory mechanisms. J Neurooncol 2019; 144:453-462. [PMID: 31392597 DOI: 10.1007/s11060-019-03251-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/22/2019] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Non-invasively distinguishing aggressive from non-aggressive brain tumors is an important clinical challenge. Intracellular pH (pHi) regulation is essential for normal cell function and is normally maintained within a narrow range. Cancer cells are characterized by a reversed intracellular to extracellular pH gradient, compared to healthy cells, that is maintained by several distinct mechanisms. Previous studies have demonstrated acute pH modulation in glioblastoma detectable by chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) after blocking individual pH regulatory mechanisms. The purpose of the current study was to simultaneously block five pH regulatory mechanisms while also providing glucose as an energy substrate. We hypothesized that this approach would increase the acute pH modulation effect allowing the identification of aggressive cancer. METHODS Using a 9.4 T MRI scanner, CEST spectra were acquired sensitive to pHi using amine/amide concentration independent detection (AACID). Twelve mice were scanned approximately 11 ± 1 days after implanting 105 U87 human glioblastoma multiforme cells in the brain, before and after intraperitoneal injection of a combination of five drugs (quercetin, cariporide, dichloroacetate, acetazolamide, and pantoprazole) with and without glucose. RESULTS Two hours after combination drug injection there was a significant 0.1 ± 0.03 increase in tumor AACID value corresponding to a 0.4 decrease in pHi. After injecting the drug combination with glucose the AACID value increased by 0.18 ± 0.03 corresponding to a 0.72 decrease in pHi. AACID values were also slightly increased in contralateral tissue. CONCLUSIONS The combined drug treatment with glucose produced a large acute CEST MRI contrast indicating tumor acidification, which could be used to help localize brain cancer and monitor tumor response to chemotherapy.
Collapse
Affiliation(s)
- Mohammed Albatany
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 1151 Richmond Street, London, ON, N65B7, Canada
- Department of Medical Biophysics, The University of Western Ontario, London, ON, N65B7, Canada
| | - Valeriy G Ostapchenko
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 1151 Richmond Street, London, ON, N65B7, Canada
| | - Susan Meakin
- Department of Biochemistry, The University of Western Ontario, London, ON, N65B7, Canada
| | - Robert Bartha
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 1151 Richmond Street, London, ON, N65B7, Canada.
- Department of Medical Biophysics, The University of Western Ontario, London, ON, N65B7, Canada.
| |
Collapse
|
3
|
Ostapchenko VG, Snir J, Suchy M, Fan J, Cobb MR, Chronik BA, Kovacs M, Prado VF, Hudson RHE, Pasternak SH, Prado MAM, Bartha R. Detection of Active Caspase-3 in Mouse Models of Stroke and Alzheimer's Disease with a Novel Dual Positron Emission Tomography/Fluorescent Tracer [ 68Ga]Ga-TC3-OGDOTA. Contrast Media Mol Imaging 2019; 2019:6403274. [PMID: 30755766 PMCID: PMC6348924 DOI: 10.1155/2019/6403274] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/20/2018] [Accepted: 11/19/2018] [Indexed: 01/22/2023]
Abstract
Apoptosis is a feature of stroke and Alzheimer's disease (AD), yet there is no accepted method to detect or follow apoptosis in the brain in vivo. We developed a bifunctional tracer [68Ga]Ga-TC3-OGDOTA containing a cell-penetrating peptide separated from fluorescent Oregon Green and 68Ga-bound labels by the caspase-3 recognition peptide DEVD. We hypothesized that this design would allow [68Ga]Ga-TC3-OGDOTA to accumulate in apoptotic cells. In vitro, Ga-TC3-OGDOTA labeled apoptotic neurons following exposure to camptothecin, oxygen-glucose deprivation, and β-amyloid oligomers. In vivo, PET showed accumulation of [68Ga]Ga-TC3-OGDOTA in the brain of mouse models of stroke or AD. Optical clearing revealed colocalization of [68Ga]Ga-TC3-OGDOTA and cleaved caspase-3 in brain cells. In stroke, [68Ga]Ga-TC3-OGDOTA accumulated in neurons in the penumbra area, whereas in AD mice [68Ga]Ga-TC3-OGDOTA was found in single cells in the forebrain and diffusely around amyloid plaques. In summary, this bifunctional tracer is selectively associated with apoptotic cells in vitro and in vivo in brain disease models and represents a novel tool for apoptosis detection that can be used in neurodegenerative diseases.
Collapse
Affiliation(s)
- Valeriy G. Ostapchenko
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Jonatan Snir
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Mojmir Suchy
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Jue Fan
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - M. Rebecca Cobb
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Neuroscience Program, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Blaine A. Chronik
- Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Michael Kovacs
- Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Lawson Health Research Institute, 268 Grosvenor Street, London, ON, Canada N6A 4V2
| | - Vania F. Prado
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Anatomy and Cell Biology, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Robert H. E. Hudson
- Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Stephen H. Pasternak
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Clinical Neurological Sciences, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Marco A. M. Prado
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Anatomy and Cell Biology, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| | - Robert Bartha
- Robarts Research Institute, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
- Department of Medical Biophysics, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7
| |
Collapse
|
4
|
Beraldo FH, Ostapchenko VG, Xu JZ, Di Guglielmo GM, Fan J, Nicholls PJ, Caron MG, Prado VF, Prado MAM. Mechanisms of neuroprotection against ischemic insult by stress-inducible phosphoprotein-1/prion protein complex. J Neurochem 2018; 145:68-79. [PMID: 29265373 PMCID: PMC7887631 DOI: 10.1111/jnc.14281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 02/02/2023]
Abstract
Stress-inducible phosphoprotein 1 (STI1) acts as a neuroprotective factor in the ischemic brain and its levels are increased following ischemia. Previous work has suggested that some of these STI1 actions in a stroke model depend on the recruitment of bone marrow-derived stem cells to improve outcomes after ischemic insult. However, STI1 can directly increase neuroprotective signaling in neurons by engaging with the cellular prion protein (PrPC ) and activating α7 nicotinic acetylcholine receptors (α7nAChR). Given that α7nAChR activation has also been involved in neuroprotection in stroke, it is possible that STI1 can have direct actions on neurons to prevent deleterious consequences of ischemic insults. Here, we tested this hypothesis by exposing primary neuronal cultures to 1-h oxygen-glucose deprivation (OGD) and reperfusion and assessing signaling pathways activated by STI1/PrPC . Our results demonstrated that STI1 treatment significantly decreased apoptosis and cell death in mouse neurons submitted to OGD in a manner that was dependent on PrPC and α7nAChR, but also on the activin A receptor 1 (ALK2), which has emerged as a signaling partner of STI1. Interestingly, pharmacological inhibition of the ALK2 receptor prevented neuroprotection by STI1, while activation of ALK2 receptors by bone morphogenetic protein 4 (BMP4) either before or after OGD was effective in decreasing neuronal death induced by ischemia. We conclude that PrPC /STI1 engagement and its subsequent downstream signaling cascades involving α7nAChR as well as the ALK2 receptor may be activated in neurons by increased levels of STI1. This signaling pathway protects neurons from ischemic insults.
Collapse
Affiliation(s)
- Flavio H. Beraldo
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Valeriy G. Ostapchenko
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Jason Z. Xu
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Gianni M. Di Guglielmo
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Jue Fan
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Peter J. Nicholls
- Psychiatry & Behavioral Sciences, Duke University, Durham, North Carolina, USA
| | - Marc G. Caron
- Department of Cell Biology, Duke University, Durham, North Carolina, USA
| | - Vania F. Prado
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Marco A. M. Prado
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
5
|
Lackie RE, Maciejewski A, Ostapchenko VG, Marques-Lopes J, Choy WY, Duennwald ML, Prado VF, Prado MAM. The Hsp70/Hsp90 Chaperone Machinery in Neurodegenerative Diseases. Front Neurosci 2017; 11:254. [PMID: 28559789 PMCID: PMC5433227 DOI: 10.3389/fnins.2017.00254] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/20/2017] [Indexed: 12/12/2022] Open
Abstract
The accumulation of misfolded proteins in the human brain is one of the critical features of many neurodegenerative diseases, including Alzheimer's disease (AD). Assembles of beta-amyloid (Aβ) peptide—either soluble (oligomers) or insoluble (plaques) and of tau protein, which form neurofibrillary tangles, are the major hallmarks of AD. Chaperones and co-chaperones regulate protein folding and client maturation, but they also target misfolded or aggregated proteins for refolding or for degradation, mostly by the proteasome. They form an important line of defense against misfolded proteins and are part of the cellular quality control system. The heat shock protein (Hsp) family, particularly Hsp70 and Hsp90, plays a major part in this process and it is well-known to regulate protein misfolding in a variety of diseases, including tau levels and toxicity in AD. However, the role of Hsp90 in regulating protein misfolding is not yet fully understood. For example, knockdown of Hsp90 and its co-chaperones in a Caenorhabditis elegans model of Aβ misfolding leads to increased toxicity. On the other hand, the use of Hsp90 inhibitors in AD mouse models reduces Aβ toxicity, and normalizes synaptic function. Stress-inducible phosphoprotein 1 (STI1), an intracellular co-chaperone, mediates the transfer of clients from Hsp70 to Hsp90. Importantly, STI1 has been shown to regulate aggregation of amyloid-like proteins in yeast. In addition to its intracellular function, STI1 can be secreted by diverse cell types, including astrocytes and microglia and function as a neurotrophic ligand by triggering signaling via the cellular prion protein (PrPC). Extracellular STI1 can prevent Aβ toxic signaling by (i) interfering with Aβ binding to PrPC and (ii) triggering pro-survival signaling cascades. Interestingly, decreased levels of STI1 in C. elegans can also increase toxicity in an amyloid model. In this review, we will discuss the role of intracellular and extracellular STI1 and the Hsp70/Hsp90 chaperone network in mechanisms underlying protein misfolding in neurodegenerative diseases, with particular focus on AD.
Collapse
Affiliation(s)
- Rachel E Lackie
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada.,Program in Neuroscience, University of Western OntarioLondon, ON, Canada
| | - Andrzej Maciejewski
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada.,Department of Biochemistry, University of Western OntarioLondon, ON, Canada
| | - Valeriy G Ostapchenko
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada
| | - Jose Marques-Lopes
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada
| | - Wing-Yiu Choy
- Department of Biochemistry, University of Western OntarioLondon, ON, Canada
| | - Martin L Duennwald
- Department of Pathology and Laboratory Medicine, University of Western OntarioLondon, ON, Canada
| | - Vania F Prado
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada.,Program in Neuroscience, University of Western OntarioLondon, ON, Canada.,Department of Physiology and Pharmacology, University of Western OntarioLondon, ON, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western OntarioLondon, ON, Canada
| | - Marco A M Prado
- Molecular Medicine, Robarts Research Institute, University of Western OntarioLondon, ON, Canada.,Program in Neuroscience, University of Western OntarioLondon, ON, Canada.,Department of Physiology and Pharmacology, University of Western OntarioLondon, ON, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western OntarioLondon, ON, Canada
| |
Collapse
|
6
|
Beraldo FH, Ostapchenko VG, Caetano FA, Guimaraes ALS, Ferretti GDS, Daude N, Bertram L, Nogueira KOPC, Silva JL, Westaway D, Cashman NR, Martins VR, Prado VF, Prado MAM. Regulation of Amyloid β Oligomer Binding to Neurons and Neurotoxicity by the Prion Protein-mGluR5 Complex. J Biol Chem 2016; 291:21945-21955. [PMID: 27563063 DOI: 10.1074/jbc.m116.738286] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 12/24/2022] Open
Abstract
The prion protein (PrPC) has been suggested to operate as a scaffold/receptor protein in neurons, participating in both physiological and pathological associated events. PrPC, laminin, and metabotropic glutamate receptor 5 (mGluR5) form a protein complex on the plasma membrane that can trigger signaling pathways involved in neuronal differentiation. PrPC and mGluR5 are co-receptors also for β-amyloid oligomers (AβOs) and have been shown to modulate toxicity and neuronal death in Alzheimer's disease. In the present work, we addressed the potential crosstalk between these two signaling pathways, laminin-PrPC-mGluR5 or AβO-PrPC-mGluR5, as well as their interplay. Herein, we demonstrated that an existing complex containing PrPC-mGluR5 has an important role in AβO binding and activity in neurons. A peptide mimicking the binding site of laminin onto PrPC (Ln-γ1) binds to PrPC and induces intracellular Ca2+ increase in neurons via the complex PrPC-mGluR5. Ln-γ1 promotes internalization of PrPC and mGluR5 and transiently decreases AβO biding to neurons; however, the peptide does not impact AβO toxicity. Given that mGluR5 is critical for toxic signaling by AβOs and in prion diseases, we tested whether mGlur5 knock-out mice would be susceptible to prion infection. Our results show mild, but significant, effects on disease progression, without affecting survival of mice after infection. These results suggest that PrPC-mGluR5 form a functional response unit by which multiple ligands can trigger signaling. We propose that trafficking of PrPC-mGluR5 may modulate signaling intensity by different PrPC ligands.
Collapse
Affiliation(s)
| | | | - Fabiana A Caetano
- From the Robarts Research Institute and the Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5B7,Canada
| | - Andre L S Guimaraes
- From the Robarts Research Institute and the Universidade Estadual de Montes Claros, Montes Claros, MG 39401-089, Brazil
| | - Giulia D S Ferretti
- From the Robarts Research Institute and the Programa de Biologia Estrutural, Instituto de Bioquimica Medica Leopoldo de Meis, Instututo Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonacia Magnetica Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Nathalie Daude
- the Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta T6G 2M8, Canada
| | - Lisa Bertram
- the Center for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Katiane O P C Nogueira
- From the Robarts Research Institute and the Instituto de Ciências Exatas e Biológicas, Departamento de Ciências Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro S/N, Ouro Preto, Minas Gerais 35400-000, Brazil
| | - Jerson L Silva
- the Programa de Biologia Estrutural, Instituto de Bioquimica Medica Leopoldo de Meis, Instututo Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonacia Magnetica Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - David Westaway
- the Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta T6G 2M8, Canada
| | - Neil R Cashman
- the Center for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Vilma R Martins
- the International Center for Research and Education, A. C. Camargo Cancer Center, São Paulo, SP CEP 01509-010, Brazil, and
| | - Vania F Prado
- From the Robarts Research Institute and the Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5B7,Canada, the Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Marco A M Prado
- From the Robarts Research Institute and the Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5B7,Canada, the Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A 3K7, Canada
| |
Collapse
|
7
|
Soares IN, Caetano FA, Pinder J, Rodrigues BR, Beraldo FH, Ostapchenko VG, Durette C, Pereira GS, Lopes MH, Queiroz-Hazarbassanov N, Cunha IW, Sanematsu PI, Suzuki S, Bleggi-Torres LF, Schild-Poulter C, Thibault P, Dellaire G, Martins VR, Prado VF, Prado MAM. Regulation of stress-inducible phosphoprotein 1 nuclear retention by protein inhibitor of activated STAT PIAS1. Mol Cell Proteomics 2013; 12:3253-70. [PMID: 23938469 DOI: 10.1074/mcp.m113.031005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Stress-inducible phosphoprotein 1 (STI1), a cochaperone for Hsp90, has been shown to regulate multiple pathways in astrocytes, but its contributions to cellular stress responses are not fully understood. We show that in response to irradiation-mediated DNA damage stress STI1 accumulates in the nucleus of astrocytes. Also, STI1 haploinsufficiency decreases astrocyte survival after irradiation. Using yeast two-hybrid screenings we identified several nuclear proteins as STI1 interactors. Overexpression of one of these interactors, PIAS1, seems to be specifically involved in STI1 nuclear retention and in directing STI1 and Hsp90 to specific sub-nuclear regions. PIAS1 and STI1 co-immunoprecipitate and PIAS1 can function as an E3 SUMO ligase for STI. Using mass spectrometry we identified five SUMOylation sites in STI1. A STI1 mutant lacking these five sites is not SUMOylated, but still accumulates in the nucleus in response to increased expression of PIAS1, suggesting the possibility that a direct interaction with PIAS1 could be responsible for STI1 nuclear retention. To test this possibility, we mapped the interaction sites between PIAS1 and STI1 using yeast-two hybrid assays and surface plasmon resonance and found that a large domain in the N-terminal region of STI1 interacts with high affinity with amino acids 450-480 of PIAS1. Knockdown of PIAS1 in astrocytes impairs the accumulation of nuclear STI1 in response to irradiation. Moreover, a PIAS1 mutant lacking the STI1 binding site is unable to increase STI1 nuclear retention. Interestingly, in human glioblastoma multiforme PIAS1 expression is increased and we found a significant correlation between increased PIAS1 expression and STI1 nuclear localization. These experiments provide evidence that direct interaction between STI1 and PIAS1 is involved in the accumulation of nuclear STI1. This retention mechanism could facilitate nuclear chaperone activity.
Collapse
Affiliation(s)
- Iaci N Soares
- Robarts Research Institute, The University of Western Ontario, London, ON, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ostapchenko VG, Beraldo FH, Guimarães ALS, Mishra S, Guzman M, Fan J, Martins VR, Prado VF, Prado MAM. Increased prion protein processing and expression of metabotropic glutamate receptor 1 in a mouse model of Alzheimer's disease. J Neurochem 2013; 127:415-25. [PMID: 23651058 DOI: 10.1111/jnc.12296] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 12/14/2022]
Abstract
Prion protein (PrP(C) ), a glycosylphosphatidylinositol-anchored protein corrupted in prion diseases, has been shown recently to interact with group I metabotropic glutamate receptors (mGluRs). Moreover, both PrP(C) and mGluRs were proposed to function as putative receptors for β-amyloid in Alzheimer's disease. PrP(C) can be processed in neurons via α or β-cleavage to produce PrP(C) fragments that are neuroprotective or toxic, respectively. We found PrP(C) α-cleavage to be 2-3 times higher in the cortex of APPswe/PS1dE9 mice, a mouse model of Alzheimer's disease. A similar age-dependent increase was observed for PrP(C) β-cleavage. Moreover, we observed considerable age-dependent increase in cortical expression of mGluR1, but not mGluR5. Exposure of cortical neuronal cultures to β-amyloid oligomers upregulated mGluR1 and PrP(C) α-cleavage, while activation of group I mGluRs increased PrP(C) shedding from the membrane, likely due to increased levels of a disintegrin and metalloprotease10, a key disintegrin for PrP(C) shedding. Interestingly, a similar increase in a disintegrin and metalloprotease10 was detected in the cortex of 9-month-old APPswe/PS1dE9 animals. Our experiments reveal novel and complex processing of PrP(C) in connection with mGluR overexpression that seems to be triggered by β-amyloid peptides. Prion protein (PrP(C) ) and metabotropic glutamate receptors (mGluR) are implicated in Alzheimer's disease (AD). We found age-dependent increase in PrP(C) processing, ADAM10 and mGluR1 levels in AD mouse model. These changes could be reproduced in cultured cortical neurons treated with Aβ peptide. Our findings suggest that increased levels of Aβ can trigger compensatory responses that may affect neuronal toxicity.
Collapse
Affiliation(s)
- Valeriy G Ostapchenko
- Robarts Research Institute, Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Santos TG, Beraldo FH, Hajj GNM, Lopes MH, Roffe M, Lupinacci FCS, Ostapchenko VG, Prado VF, Prado MAM, Martins VR. Laminin-γ1 chain and stress inducible protein 1 synergistically mediate PrPC-dependent axonal growth via Ca2+ mobilization in dorsal root ganglia neurons. J Neurochem 2012; 124:210-23. [PMID: 23145988 DOI: 10.1111/jnc.12091] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 11/01/2012] [Accepted: 11/01/2012] [Indexed: 12/01/2022]
Abstract
Prion protein (PrP(C)) is a cell surface glycoprotein that is abundantly expressed in nervous system. The elucidation of the PrP(C) interactome network and its significance on neural physiology is crucial to understanding neurodegenerative events associated with prion and Alzheimer's diseases. PrP(C) co-opts stress inducible protein 1/alpha7 nicotinic acetylcholine receptor (STI1/α7nAChR) or laminin/Type I metabotropic glutamate receptors (mGluR1/5) to modulate hippocampal neuronal survival and differentiation. However, potential cross-talk between these protein complexes and their role in peripheral neurons has never been addressed. To explore this issue, we investigated PrP(C)-mediated axonogenesis in peripheral neurons in response to STI1 and laminin-γ1 chain-derived peptide (Ln-γ1). STI1 and Ln-γ1 promoted robust axonogenesis in wild-type neurons, whereas no effect was observed in neurons from PrP(C) -null mice. PrP(C) binding to Ln-γ1 or STI1 led to an increase in intracellular Ca(2+) levels via distinct mechanisms: STI1 promoted extracellular Ca(2+) influx, and Ln-γ1 released calcium from intracellular stores. Both effects depend on phospholipase C activation, which is modulated by mGluR1/5 for Ln-γ1, but depends on, C-type transient receptor potential (TRPC) channels rather than α7nAChR for STI1. Treatment of neurons with suboptimal concentrations of both ligands led to synergistic actions on PrP(C)-mediated calcium response and axonogenesis. This effect was likely mediated by simultaneous binding of the two ligands to PrP(C). These results suggest a role for PrP(C) as an organizer of diverse multiprotein complexes, triggering specific signaling pathways and promoting axonogenesis in the peripheral nervous system.
Collapse
Affiliation(s)
- Tiago G Santos
- International Research Center, A.C. Camargo Hospital, São Paulo, Brazil
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Ostapchenko VG, Gasparian ME, Kosinsky YA, Efremov RG, Dolgikh DA, Kirpichnikov MP. Dissecting structural basis of the unique substrate selectivity of human enteropeptidase catalytic subunit. J Biomol Struct Dyn 2012; 30:62-73. [DOI: 10.1080/07391102.2012.674249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
11
|
Lee YJ, Savtchenko R, Ostapchenko VG, Makarava N, Baskakov IV. Molecular structure of amyloid fibrils controls the relationship between fibrillar size and toxicity. PLoS One 2011; 6:e20244. [PMID: 21625461 PMCID: PMC3098877 DOI: 10.1371/journal.pone.0020244] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 04/26/2011] [Indexed: 12/29/2022] Open
Abstract
Background According to the prevailing view, soluble oligomers or small fibrillar fragments are considered to be the most toxic species in prion diseases. To test this hypothesis, two conformationally different amyloid states were produced from the same highly pure recombinant full-length prion protein (rPrP). The cytotoxic potential of intact fibrils and fibrillar fragments generated by sonication from these two states was tested using cultured cells. Methodology/Principal Findings For one amyloid state, fibril fragmentation was found to enhance its cytotoxic potential, whereas for another amyloid state formed within the same amino acid sequence, the fragmented fibrils were found to be substantially less toxic than the intact fibrils. Consistent with the previous studies, the toxic effects were more pronounced for cell cultures expressing normal isoform of the prion protein (PrPC) at high levels confirming that cytotoxicity was in part PrPC-dependent. Silencing of PrPC expression by small hairpin RNAs designed to silence expression of human PrPC (shRNA-PrPC) deminished the deleterious effects of the two amyloid states to a different extent, suggesting that the role of PrPC-mediated and PrPC-independent mechanisms depends on the structure of the aggregates. Conclusions/Significance This work provides a direct illustration that the relationship between an amyloid's physical dimension and its toxic potential is not unidirectional but is controlled by the molecular structure of prion protein (PrP) molecules within aggregated states. Depending on the structure, a decrease in size of amyloid fibrils can either enhance or abolish their cytotoxic effect. Regardless of the molecular structure or size of PrP aggregates, silencing of PrPC expression can be exploited to reduce their deleterious effects.
Collapse
Affiliation(s)
- Young Jin Lee
- Department of Anatomy and Neurobiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Regina Savtchenko
- Department of Anatomy and Neurobiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Valeriy G. Ostapchenko
- Department of Anatomy and Neurobiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Natallia Makarava
- Department of Anatomy and Neurobiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Ilia V. Baskakov
- Department of Anatomy and Neurobiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
12
|
Tycko R, Savtchenko R, Ostapchenko VG, Makarava N, Baskakov IV. The α-helical C-terminal domain of full-length recombinant PrP converts to an in-register parallel β-sheet structure in PrP fibrils: evidence from solid state nuclear magnetic resonance. Biochemistry 2011; 49:9488-97. [PMID: 20925423 DOI: 10.1021/bi1013134] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We report the results of solid state nuclear magnetic resonance (NMR) measurements on amyloid fibrils formed by the full-length prion protein PrP (residues 23−231, Syrian hamster sequence). Measurements of intermolecular 13C−13C dipole−dipole couplings in selectively carbonyl-labeled samples indicate that β-sheets in these fibrils have an in-register parallel structure, as previously observed in amyloid fibrils associated with Alzheimer’s disease and type 2 diabetes and in yeast prion fibrils. Two-dimensional 13C−13C and 15N−13C solid state NMR spectra of a uniformly 15N- and 13C-labeled sample indicate that a relatively small fraction of the full sequence, localized to the C-terminal end, forms the structurally ordered, immobilized core. Although unique site-specific assignments of the solid state NMR signals cannot be obtained from these spectra, analysis with a Monte Carlo/simulated annealing algorithm suggests that the core is comprised primarily of residues in the 173−224 range. These results are consistent with earlier electron paramagnetic resonance studies of fibrils formed by residues 90−231 of the human PrP sequence, formed under somewhat different conditions [Cobb, N. J., Sonnichsen, F. D., McHaourab, H., and Surewicz, W. K. (2007) Proc. Natl. Acad. Sci. U.S.A. 104, 18946−18951], suggesting that an in-register parallel β-sheet structure formed by the C-terminal end may be a general feature of PrP fibrils prepared in vitro.
Collapse
Affiliation(s)
- Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
| | | | | | | | | |
Collapse
|
13
|
El Moustaine D, Perrier V, Van Ba IAT, Meersman F, Ostapchenko VG, Baskakov IV, Lange R, Torrent J. Amyloid features and neuronal toxicity of mature prion fibrils are highly sensitive to high pressure. J Biol Chem 2011; 286:13448-59. [PMID: 21357423 PMCID: PMC3075691 DOI: 10.1074/jbc.m110.192872] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 02/24/2011] [Indexed: 12/22/2022] Open
Abstract
Prion proteins (PrP) can aggregate into toxic and possibly infectious amyloid fibrils. This particular macrostructure confers on them an extreme and still unexplained stability. To provide mechanistic insights into this self-assembly process, we used high pressure as a thermodynamic tool for perturbing the structure of mature amyloid fibrils that were prepared from recombinant full-length mouse PrP. Application of high pressure led to irreversible loss of several specific amyloid features, such as thioflavin T and 8-anilino-1-naphthalene sulfonate binding, alteration of the characteristic proteinase K digestion pattern, and a significant decrease in the β-sheet structure and cytotoxicity of amyloid fibrils. Partial disaggregation of the mature fibrils into monomeric soluble PrP was observed. The remaining amyloid fibrils underwent a change in secondary structure that led to morphologically different fibrils composed of a reduced number of proto-filaments. The kinetics of these reactions was studied by recording the pressure-induced dissociation of thioflavin T from the amyloid fibrils. Analysis of the pressure and temperature dependence of the relaxation rates revealed partly unstructured and hydrated kinetic transition states and highlighted the importance of collapsing and hydrating inter- and intramolecular cavities to overcome the high free energy barrier that stabilizes amyloid fibrils.
Collapse
Affiliation(s)
- Driss El Moustaine
- From the University of Montpellier 2 and
- INSERM, U710, Montpellier F-34095, France
- Ecole Pratique des Hautes Études, Paris F-75007, France
| | - Veronique Perrier
- From the University of Montpellier 2 and
- INSERM, U710, Montpellier F-34095, France
- Ecole Pratique des Hautes Études, Paris F-75007, France
| | - Isabelle Acquatella-Tran Van Ba
- From the University of Montpellier 2 and
- INSERM, U710, Montpellier F-34095, France
- Ecole Pratique des Hautes Études, Paris F-75007, France
| | - Filip Meersman
- the Department of Chemistry, Katholieke Universiteit Leuven, Leuven B-3001, Belgium, and
| | - Valeriy G. Ostapchenko
- the Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Ilia V. Baskakov
- the Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Reinhard Lange
- From the University of Montpellier 2 and
- INSERM, U710, Montpellier F-34095, France
- Ecole Pratique des Hautes Études, Paris F-75007, France
| | - Joan Torrent
- From the University of Montpellier 2 and
- INSERM, U710, Montpellier F-34095, France
- Ecole Pratique des Hautes Études, Paris F-75007, France
| |
Collapse
|
14
|
Ostapchenko VG, Sawaya MR, Makarava N, Savtchenko R, Nilsson KPR, Eisenberg D, Baskakov IV. Two amyloid States of the prion protein display significantly different folding patterns. J Mol Biol 2010; 400:908-21. [PMID: 20553730 DOI: 10.1016/j.jmb.2010.05.051] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 04/27/2010] [Accepted: 05/21/2010] [Indexed: 12/16/2022]
Abstract
It has been well established that a single amino acid sequence can give rise to several conformationally distinct amyloid states. The extent to which amyloid structures formed within the same sequence are different, however, remains unclear. To address this question, we studied two amyloid states (referred to as R- and S-fibrils) produced in vitro from highly purified full-length recombinant prion protein. Several biophysical techniques including X-ray diffraction, CD, Fourier transform infrared spectroscopy (FTIR), hydrogen-deuterium exchange, proteinase K digestion, and binding of a conformation-sensitive fluorescence dye revealed that R- and S-fibrils have substantially different secondary, tertiary, and quaternary structures. While both states displayed a 4. 8-A meridional X-ray diffraction typical for amyloid cross-beta-spines, they showed markedly different equatorial profiles, suggesting different folding pattern of beta-strands. The experiments on hydrogen-deuterium exchange monitored by FTIR revealed that only small fractions of amide protons were protected in R- or S-fibrils, an argument for the dynamic nature of their cross-beta-structure. Despite this fact, both amyloid states were found to be very stable conformationally as judged from temperature-induced denaturation monitored by FTIR and the conformation-sensitive dye. Upon heating to 80 degrees C, only local unfolding was revealed, while individual state-specific cross-beta features were preserved. The current studies demonstrated that the two amyloid states formed by the same amino acid sequence exhibited significantly different folding patterns that presumably reflect two different architectures of cross-beta-structure. Both S- and R-fibrils, however, shared high conformational stability, arguing that the energy landscape for protein folding and aggregation can contain several deep free-energy minima.
Collapse
Affiliation(s)
- Valeriy G Ostapchenko
- Center for Biomedical Engineering and Technology, University of Maryland, Baltimore, MD 21201, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
A key structural component of amyloid fibrils is a highly ordered, crystalline-like cross-beta-sheet core. Conformationally different amyloid structures can be formed within the same amino acid sequence. It is generally assumed that individual fibrils consist of conformationally uniform cross-beta-structures. Using mammalian recombinant prion protein (PrP), we showed that, contrary to common perception, amyloid is capable of accommodating a significant conformational switching within individual fibrils. The conformational switch occurred when the amino acid sequence of a PrP variant used as a precursor substrate in a fibrillation reaction was not compatible with the strain-specific conformation of the fibrillar template. Despite the mismatch in amino acid sequences between the substrate and template, individual fibrils recruited the heterologous PrP variant; however, the fibril elongation proceeded through a conformational adaptation, resulting in a change in amyloid strain within individual fibrils. This study illustrates the high adaptation potential of amyloid structures and suggests that conformational switching within individual fibrils may account for adaptation of amyloid strains to a heterologous substrate. This work proposes a new mechanistic explanation for the phenomenon of strain conversion and illustrates the direction in evolution of amyloid structures. This study also provides a direct illustration that catalytic activity of self-replicating amyloid structures is not ultimately coupled with their templating effect.
Collapse
Affiliation(s)
- Natallia Makarava
- Medical Biotechnology Center, University of Maryland Biotechnology Institute, Baltimore, MD 21201, USA
| | | | | | | |
Collapse
|
16
|
Abstract
The primary structure of the prion protein (PrP) is believed to be the key factor in regulating the species barrier of prion transmission. Because the strength of the species barrier was found to be affected by the prion strain, the extent to which the barrier can indeed be attributed to differences in the PrP primary structures of either donor and acceptor species remains unclear. In this study, we exploited the intrinsic property of PrP to polymerize spontaneously into disease-related amyloid conformations in the absence of a strain-specified template and analyzed polymerization of mouse and hamster full-length recombinant PrPs. Unexpectedly, we found no evidence of species specificity in cross-seeding polymerization assays. Even when both recombinant PrP variants were present in mixtures, preformed mouse or hamster fibrils displayed no selectivity in elongation reactions and consumed equally well both homologous and heterologous substrates. Analysis of individual fibrils revealed that fibrils can elongate in a bidirectional or unidirectional manner. Our work revealed that, in the absence of a cellular environment, post-translational modifications, or strain-specified conformational constraints, PrP fibrils are intrinsically promiscuous and capable of utilizing heterologous PrP variants as a substrate in a highly efficient manner. This study suggests that amyloid structures are capable of accommodating local perturbations arising because of a mismatch in amino acid sequences and highlights the promiscuous nature of the self-propagating activity of amyloid fibrils.
Collapse
Affiliation(s)
- Natallia Makarava
- Medical Biotechnology Center, University of Maryland Biotechnology Institute, Department of Biochemistry and Molecular Biology, Baltimore 21201, USA
| | | | | | | |
Collapse
|
17
|
Gasparian ME, Ostapchenko VG, Yagolovich AV, Tsygannik IN, Chernyak BV, Dolgikh DA, Kirpichnikov MP. Overexpression and refolding of thioredoxin/TRAIL fusion from inclusion bodies and further purification of TRAIL after cleavage by enteropeptidase. Biotechnol Lett 2007; 29:1567-73. [PMID: 17609857 DOI: 10.1007/s10529-007-9446-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 05/31/2007] [Accepted: 05/31/2007] [Indexed: 11/27/2022]
Abstract
The human TRAIL gene (encoding residues 114-281) was synthesized by PCR and cloned into plasmid pET-32a. High level expression (1.5 g l(-1)) of thioredoxin/TRAIL fusion was achieved in Escherichia coli strain BL21(DE3), mainly as inclusion bodies. Refolded fusion thioredoxin/TRAIL was cleaved by enteropeptidase and TRAIL was separated from thioredoxin on Ni-NTA agarose. High yield (400 mg l(-1)) of TRAIL without N-terminal methionine and His tag was obtained. Sedimentation coefficient demonstrated that 98% of TRAIL formed trimers. TRAIL formed crystals of space group P3 (1) with unit-cell dimensions a = b = 72.5 A, c = 141.5 A. Apoptosis induced in HeLa cells by purified TRAIL was 5-fold enhanced by emetine.
Collapse
Affiliation(s)
- Marine E Gasparian
- Laboratory of Protein Engineering, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, 16/10 Miklukho-Maklaya, Moscow, 117997 GSP, Russia.
| | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
The synthetic gene encoding human enteropeptidase light chain (L-HEP) was cloned into plasmid pET-32a downstream from the gene of fusion partner thioredoxin immediately after the DNA sequence encoding the enteropeptidase recognition site. The fusion protein thioredoxin (Trx)/L-HEP was expressed in Escherichia coli BL21(DE3). Autocatalytic cleavage of the fusion protein and activation of recombinant L-HEP were achieved by solubilization of inclusion bodies and refolding of Trx/L-HEP fusion protein. The kinetic parameters of human and bovine enteropeptidases in the presence of different concentrations of Ca2+ and Na+ for cleavage of the specific substrate GD4K-na and nonspecific substrates such as small ester Z-Lys-SBzl and chromogenic substrates Z-Ala-X-Arg-pNA have been comparatively analyzed. It is demonstrated that positively charged ions increased the Michaelis constant (Km) for cleavage of specific substrate GD4K-na, while the catalytic constant (k(cat)) remained practically unchanged. L-HEP demonstrated secondary specificity to the chromogenic substrate Z-Ala-Phe-Arg-pNA with k(cat)/Km 260 mM(-1) x sec(-1). Enzymatic activity of L-HEP was suppressed by inhibitors of trypsin-like and cysteine (E-64), but not metallo-, amino-, or chymotrypsin-like proteinases. L-HEP was active over a broad range of pH (6-9) with optimum activity at pH 7.5, and it demonstrated high stability to different denaturing agents.
Collapse
Affiliation(s)
- M E Gasparian
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.
| | | | | | | |
Collapse
|
19
|
Gasparian ME, Ostapchenko VG, Schulga AA, Dolgikh DA, Kirpichnikov MP. Expression, purification, and characterization of human enteropeptidase catalytic subunit in Escherichia coli. Protein Expr Purif 2003; 31:133-9. [PMID: 12963350 DOI: 10.1016/s1046-5928(03)00159-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Enteropeptidase (synonym:enterokinase, EC 3.4.21.9) is a heterodimeric serine protease of the intestinal brush border that activates trypsinogen by highly specific cleavage of the trypsinogen activation peptide following the sequence (Asp)(4)-Lys. The DNA sequence encoding the light chain (catalytic subunit) of human enteropeptidase (GenBank Accession No. U09860) was synthesized from 26 oligonucleotides by polymerase chain reaction and cloned into plasmid pET-32a downstream to the gene of fusion partner thioredoxin immediately after the DNA sequence encoding enteropeptidase recognition site. The fusion protein thioredoxin/human enteropeptidase light chain was expressed in Escherichia coli BL21(DE3) strain in both soluble and insoluble forms. The soluble recombinant fusion protein failed to undergo autocatalytic cleavage and activation; however, autocatalytic cleavage and activation of recombinant human enteropeptidase light chain (L-HEP) were achieved by solubilization and renaturation of the fusion protein from inclusion bodies and the active L-HEP was purified on agarose-linked soybean trypsin inhibitor. The purified L-HEP cleaved the synthetic peptide substrate Gly-Asp-Asp-Asp-Asp-Lys-beta-naphthylamide with kinetic parameters K(m)=0.16 mM and k(cat)=115 s(-1) and small ester Z-Lys-SBzl with K(m)=140 microM, k(cat)=133 s(-1). L-HEP associated with soybean trypsin inhibitor slowly and small ester Z-Lys-SBzl cleavage was inhibited with K(i)(*)=2.3 nM. L-HEP digested thioredoxin/human epidermal growth factor fusion protein five times faster than equal activity units of bovine recombinant light chain (EKMax, Invitrogen) at the same conditions.
Collapse
Affiliation(s)
- Marine E Gasparian
- Laboratory of Protein Engineering, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, 16/10 Miklukho-Maklaya, 117997 GSP, Moscow, Russia.
| | | | | | | | | |
Collapse
|