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Reimann RR, Puzio M, Rosati A, Emmenegger M, Schneider BL, Valdés P, Huang D, Caflisch A, Aguzzi A. Rapid ex vivo reverse genetics identifies the essential determinants of prion protein toxicity. Brain Pathol 2022; 33:e13130. [PMID: 36329611 PMCID: PMC10041163 DOI: 10.1111/bpa.13130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
Abstract
The cellular prion protein PrPC mediates the neurotoxicity of prions and other protein aggregates through poorly understood mechanisms. Antibody-derived ligands against the globular domain of PrPC (GDL) can also initiate neurotoxicity by inducing an intramolecular R208 -H140 hydrogen bond ("H-latch") between the α2-α3 and β2-α2 loops of PrPC . Importantly, GDL that suppresses the H-latch prolong the life of prion-infected mice, suggesting that GDL toxicity and prion infections exploit convergent pathways. To define the structural underpinnings of these phenomena, we transduced 19 individual PrPC variants to PrPC -deficient cerebellar organotypic cultured slices using adenovirus-associated viral vectors (AAV). We report that GDL toxicity requires a single N-proximal cationic residue (K27 or R27 ) within PrPC . Alanine substitution of K27 also prevented the toxicity of PrPC mutants that induce Shmerling syndrome, a neurodegenerative disease that is suppressed by co-expression of wild-type PrPC . K27 may represent an actionable target for compounds aimed at preventing prion-related neurodegeneration.
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Affiliation(s)
| | - Martina Puzio
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Antonella Rosati
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Marc Emmenegger
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Bernard L. Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Pamela Valdés
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Danzhi Huang
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology University of Zurich Zurich Switzerland
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2
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Ilie IM, Caflisch A. Antibody binding increases the flexibility of the prion protein. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140827. [PMID: 35931365 DOI: 10.1016/j.bbapap.2022.140827] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/29/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Prion diseases are associated with the conversion of the cellular prion protein (PrP) into a pathogenic conformer (PrPSc). A proposed therapeutic approach to avoid the pathogenic transformation is to develop antibodies that bind to PrP and stabilize its structure. POM1 and POM6 are two monoclonal antibodies that bind the globular domain of PrP and have different biological responses, i.e., trigger neurotoxicity mimicking prion infections (POM1) or prevent neurotoxicity (POM6). The crystal structures of PrP in complex with the two antibodies show similar epitopes which seems inconsistent with the opposite phenotypes. Here, we investigate the influence of the POM1 and POM6 antibodies on the flexibility of the mouse PrP by molecular dynamics simulations. The simulations reveal that the POM6/PrP interface is less stable than the POM1/PrP interface, ascribable to localized polar mismatches at the interface, despite the former complex having a larger epitope than the latter. In the presence of any of the two antibodies, the flexibility of the globular domain increases everywhere except for the β1-α1 loop in the POM1/PrP complex which suggests the involvement of this loop in the pathological conversion. The secondary structure of PrP is preserved whereas the polar interactions involving residues Glu146, Arg156 and Arg208 are modified upon antibody binding.
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Affiliation(s)
- Ioana M Ilie
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland.
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland.
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3
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Ilie IM, Bacci M, Vitalis A, Caflisch A. Antibody binding modulates the dynamics of the membrane-bound prion protein. Biophys J 2022; 121:2813-2825. [PMID: 35672948 DOI: 10.1016/j.bpj.2022.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/20/2022] [Accepted: 06/01/2022] [Indexed: 11/18/2022] Open
Abstract
Misfolding of the cellular prion protein (PrPC) is associated with lethal neurodegeneration. PrPC consists of a flexible tail (residues 23-123) and a globular domain (residues 124-231) whose C-terminal end is anchored to the cell membrane. The neurotoxic antibody POM1 and the innocuous antibody POM6 recognize the globular domain. Experimental evidence indicates that POM1 binding to PrPC emulates the influence on PrPC of the misfolded prion protein (PrPSc) while the binding of POM6 has the opposite biological response. Little is known about the potential interactions between flexible tail, globular domain, and the membrane. Here, we used atomistic simulations to investigate how these interactions are modulated by the binding of the Fab fragments of POM1 and POM6 to PrPC and by interstitial sequence truncations to the flexible tail. The simulations show that the binding of the antibodies restricts the range of orientations of the globular domain with respect to the membrane and decreases the distance between tail and membrane. Five of the six sequence truncations influence only marginally this distance and the contact patterns between tail and globular domain. The only exception is a truncation coupled to a charge inversion mutation of four N-terminal residues, which increases the distance of the flexible tail from the membrane. The interactions of the flexible tail and globular domain are modulated differently by the two antibodies.
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Affiliation(s)
- Ioana M Ilie
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Marco Bacci
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Andreas Vitalis
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich, Switzerland.
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4
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Dexter E, Kong Q. Neuroprotective effect and potential of cellular prion protein and its cleavage products for treatment of neurodegenerative disorders part I. a literature review. Expert Rev Neurother 2021; 21:969-982. [PMID: 34470561 DOI: 10.1080/14737175.2021.1965881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The cellular prion protein (PrPC) is well known for its pathogenic roles in prion diseases, several other neurodegenerative diseases (such as Alzheimer's disease), and multiple types of cancer, but the beneficial aspects of PrPC and its cleavage products received much less attention. AREAS COVERED Here the authors will systematically review the literatures on the negative as well as protective aspects of PrPC and its derivatives (especially PrP N-terminal N1 peptide and shed PrP). The authors will dissect the current findings on N1 and shed PrP, including evidence for their neuroprotective effects, the categories of PrPC cleavage, and numerous cleavage enzymes involved. The authors will also discuss the protective effects and therapeutic potentials of PrPC-rich exosomes. The cited articles were obtained from extensive PubMed searches of recent literature, including peer-reviewed original articles and review articles. EXPERT OPINION PrP and its N-terminal fragments have strong neuroprotective activities that should be explored for therapeutics and prophylactics development against prion disease, Alzheimer's disease and a few other neurodegenerative diseases. The strategies to develop PrP-based therapeutics and prophylactics for these neurodegenerative diseases will be discussed in a companion article (Part II).
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Affiliation(s)
- Emily Dexter
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, USA
| | - Qingzhong Kong
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, USA.,Department of Neurology, School of Medicine, Case Western Reserve University, Cleveland, USA
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5
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Nargeh H, Aliabadi F, Ajami M, Pazoki-Toroudi H. Role of Polyphenols on Gut Microbiota and the Ubiquitin-Proteasome System in Neurodegenerative Diseases. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6119-6144. [PMID: 34038102 DOI: 10.1021/acs.jafc.1c00923] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Today, neurodegenerative diseases have become a remarkable public health challenge due to their direct relation with aging. Accordingly, understanding the molecular and cellular mechanisms occurring in the pathogenesis of them is essential. Both protein aggregations as a result of the ubiquitin-proteasome system (UPS) inefficiency and gut microbiota alternation are the main pathogenic hallmarks. Polyphenols upregulating this system may decrease the developing rate of neurodegenerative diseases. Most of the dietary intake of polyphenols is converted into other microbial metabolites, which have completely different biological properties from the original polyphenols and should be thoroughly investigated. Herein, several prevalent neurodegenerative diseases are pinpointed to explain the role of gut microbiota alternations and the role of molecular changes, especially UPS down-regulation in their pathogenesis. Some of the most important polyphenols found in our diet are explained along with their microbial metabolites in the body.
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Affiliation(s)
- Hanieh Nargeh
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 1417466191, Iran
| | - Fatemeh Aliabadi
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
| | - Marjan Ajami
- Faculty of Nutrition Sciences & Food Technology, Shahid Beheshti University of Medical Sciences, 7th Floor, Bldg No. 2 SBUMS, Arabi Avenue, Daneshjoo Boulevard, Velenjak, Tehran 19839-63113, Iran
| | - Hamidreza Pazoki-Toroudi
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
- Department of Physiology and Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
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6
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Yakubu UM, Catumbela CSG, Morales R, Morano KA. Understanding and exploiting interactions between cellular proteostasis pathways and infectious prion proteins for therapeutic benefit. Open Biol 2020; 10:200282. [PMID: 33234071 PMCID: PMC7729027 DOI: 10.1098/rsob.200282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Several neurodegenerative diseases of humans and animals are caused by the misfolded prion protein (PrPSc), a self-propagating protein infectious agent that aggregates into oligomeric, fibrillar structures and leads to cell death by incompletely understood mechanisms. Work in multiple biological model systems, from simple baker's yeast to transgenic mouse lines, as well as in vitro studies, has illuminated molecular and cellular modifiers of prion disease. In this review, we focus on intersections between PrP and the proteostasis network, including unfolded protein stress response pathways and roles played by the powerful regulators of protein folding known as protein chaperones. We close with analysis of promising therapeutic avenues for treatment enabled by these studies.
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Affiliation(s)
- Unekwu M Yakubu
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX USA.,MD Anderson UTHealth Graduate School at UTHealth, Houston, TX USA
| | - Celso S G Catumbela
- MD Anderson UTHealth Graduate School at UTHealth, Houston, TX USA.,Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, McGovern Medical School at UTHealth, Houston, TX USA
| | - Rodrigo Morales
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, McGovern Medical School at UTHealth, Houston, TX USA.,Centro integrativo de biología y química aplicada (CIBQA), Universidad Bernardo O'Higgins, Santiago, Chile
| | - Kevin A Morano
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX USA
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Rozpędek-Kamińska W, Siwecka N, Wawrzynkiewicz A, Wojtczak R, Pytel D, Diehl JA, Majsterek I. The PERK-Dependent Molecular Mechanisms as a Novel Therapeutic Target for Neurodegenerative Diseases. Int J Mol Sci 2020; 21:E2108. [PMID: 32204380 PMCID: PMC7139310 DOI: 10.3390/ijms21062108] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/11/2022] Open
Abstract
Higher prevalence of neurodegenerative diseases is strictly connected with progressive aging of the world population. Interestingly, a broad range of age-related, neurodegenerative diseases is characterized by a common pathological mechanism-accumulation of misfolded and unfolded proteins within the cells. Under certain circumstances, such protein aggregates may evoke endoplasmic reticulum (ER) stress conditions and subsequent activation of the unfolded protein response (UPR) signaling pathways via the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent manner. Under mild to moderate ER stress, UPR has a pro-adaptive role. However, severe or long-termed ER stress conditions directly evoke shift of the UPR toward its pro-apoptotic branch, which is considered to be a possible cause of neurodegeneration. To this day, there is no effective cure for Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), or prion disease. Currently available treatment approaches for these diseases are only symptomatic and cannot affect the disease progression. Treatment strategies, currently under detailed research, include inhibition of the PERK-dependent UPR signaling branches. The newest data have reported that the use of small-molecule inhibitors of the PERK-mediated signaling branches may contribute to the development of a novel, ground-breaking therapeutic approach for neurodegeneration. In this review, we critically describe all the aspects associated with such targeted therapy against neurodegenerative proteopathies.
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Affiliation(s)
- Wioletta Rozpędek-Kamińska
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (N.S.); (A.W.); (R.W.)
| | - Natalia Siwecka
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (N.S.); (A.W.); (R.W.)
| | - Adam Wawrzynkiewicz
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (N.S.); (A.W.); (R.W.)
| | - Radosław Wojtczak
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (N.S.); (A.W.); (R.W.)
| | - Dariusz Pytel
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; (D.P.); (J.A.D.)
| | - J. Alan Diehl
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; (D.P.); (J.A.D.)
| | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (N.S.); (A.W.); (R.W.)
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8
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Yang Y, Liu L, Naik I, Braunstein Z, Zhong J, Ren B. Transcription Factor C/EBP Homologous Protein in Health and Diseases. Front Immunol 2017; 8:1612. [PMID: 29230213 PMCID: PMC5712004 DOI: 10.3389/fimmu.2017.01612] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/07/2017] [Indexed: 12/13/2022] Open
Abstract
C/EBP homologous protein (CHOP), known also as DNA damage-inducible transcript 3 and as growth arrest and DNA damage-inducible protein 153 (GADD153), is induced in response to certain stressors. CHOP is universally acknowledged as a main conduit to endoplasmic reticulum stress-induced apoptosis. Ongoing research established the existence of CHOP-mediated apoptosis signaling networks, for which novel downstream targets are still being determined. However, there are studies that contradict this notion and assert that apoptosis is not the only mechanism by which CHOP plays in the development of pathologies. In this review, insights into the roles of CHOP in pathophysiology are summarized at the molecular and cellular levels. We further focus on the newest advances that implicate CHOP in human diseases including cancer, diabetes, neurodegenerative disorders, and notably, fibrosis.
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Affiliation(s)
- Yuan Yang
- Center for Molecular Medicine, Medical School of Yangtze University, Jingzhou, China.,Department of Radiology, Medical School of Yangtze University, Jingzhou, China
| | - Lian Liu
- Department of Pharmacology, Medical School of Yangtze University, Jingzhou, China
| | - Ishan Naik
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, United States
| | - Zachary Braunstein
- Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Jixin Zhong
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, United States
| | - Boxu Ren
- Center for Molecular Medicine, Medical School of Yangtze University, Jingzhou, China.,Department of Radiology, Medical School of Yangtze University, Jingzhou, China
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9
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Copper- and Zinc-Promoted Interdomain Structure in the Prion Protein: A Mechanism for Autoinhibition of the Neurotoxic N-Terminus. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:35-56. [PMID: 28838668 DOI: 10.1016/bs.pmbts.2017.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The function of the cellular prion protein (PrPC), while still poorly understood, is increasingly linked to its ability to bind physiological metal ions at the cell surface. PrPC binds divalent forms of both copper and zinc through its unstructured N-terminal domain, modulating interactions between PrPC and various receptors at the cell surface and ultimately tuning downstream cellular processes. In this chapter, we briefly discuss the molecular features of copper and zinc uptake by PrPC and summarize evidence implicating these metal ions in PrP-mediated physiology. We then focus our review on recent biophysical evidence revealing a physical interaction between the flexible N-terminal and globular C-terminal domains of PrPC. This interdomain cis interaction is electrostatic in nature and is promoted by the binding of Cu2+ and Zn2+ to the N-terminal octarepeat domain. These findings, along with recent cellular studies, suggest a mechanism whereby NC interactions serve to regulate the activity and/or toxicity of the PrPC N-terminus. We discuss this potential mechanism in relation to familial prion disease mutations, lethal deletions of the PrPC central region, and neurotoxicity induced by certain globular domain ligands, including bona fide prions and toxic amyloid-β oligomers.
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10
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Wu B, McDonald AJ, Markham K, Rich CB, McHugh KP, Tatzelt J, Colby DW, Millhauser GL, Harris DA. The N-terminus of the prion protein is a toxic effector regulated by the C-terminus. eLife 2017; 6:e23473. [PMID: 28527237 PMCID: PMC5469617 DOI: 10.7554/elife.23473] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/17/2017] [Indexed: 12/23/2022] Open
Abstract
PrPC, the cellular isoform of the prion protein, serves to transduce the neurotoxic effects of PrPSc, the infectious isoform, but how this occurs is mysterious. Here, using a combination of electrophysiological, cellular, and biophysical techniques, we show that the flexible, N-terminal domain of PrPC functions as a powerful toxicity-transducing effector whose activity is tightly regulated in cis by the globular C-terminal domain. Ligands binding to the N-terminal domain abolish the spontaneous ionic currents associated with neurotoxic mutants of PrP, and the isolated N-terminal domain induces currents when expressed in the absence of the C-terminal domain. Anti-PrP antibodies targeting epitopes in the C-terminal domain induce currents, and cause degeneration of dendrites on murine hippocampal neurons, effects that entirely dependent on the effector function of the N-terminus. NMR experiments demonstrate intramolecular docking between N- and C-terminal domains of PrPC, revealing a novel auto-inhibitory mechanism that regulates the functional activity of PrPC.
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Affiliation(s)
- Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Alex J McDonald
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kathleen Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - Celeste B Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kyle P McHugh
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Jörg Tatzelt
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University, Munich, Germany
| | - David W Colby
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
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11
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Linden R. The Biological Function of the Prion Protein: A Cell Surface Scaffold of Signaling Modules. Front Mol Neurosci 2017; 10:77. [PMID: 28373833 PMCID: PMC5357658 DOI: 10.3389/fnmol.2017.00077] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/06/2017] [Indexed: 12/18/2022] Open
Abstract
The prion glycoprotein (PrPC) is mostly located at the cell surface, tethered to the plasma membrane through a glycosyl-phosphatydil inositol (GPI) anchor. Misfolding of PrPC is associated with the transmissible spongiform encephalopathies (TSEs), whereas its normal conformer serves as a receptor for oligomers of the β-amyloid peptide, which play a major role in the pathogenesis of Alzheimer’s Disease (AD). PrPC is highly expressed in both the nervous and immune systems, as well as in other organs, but its functions are controversial. Extensive experimental work disclosed multiple physiological roles of PrPC at the molecular, cellular and systemic levels, affecting the homeostasis of copper, neuroprotection, stem cell renewal and memory mechanisms, among others. Often each such process has been heralded as the bona fide function of PrPC, despite restricted attention paid to a selected phenotypic trait, associated with either modulation of gene expression or to the engagement of PrPC with a single ligand. In contrast, the GPI-anchored prion protein was shown to bind several extracellular and transmembrane ligands, which are required to endow that protein with the ability to play various roles in transmembrane signal transduction. In addition, differing sets of those ligands are available in cell type- and context-dependent scenarios. To account for such properties, we proposed that PrPC serves as a dynamic platform for the assembly of signaling modules at the cell surface, with widespread consequences for both physiology and behavior. The current review advances the hypothesis that the biological function of the prion protein is that of a cell surface scaffold protein, based on the striking similarities of its functional properties with those of scaffold proteins involved in the organization of intracellular signal transduction pathways. Those properties are: the ability to recruit spatially restricted sets of binding molecules involved in specific signaling; mediation of the crosstalk of signaling pathways; reciprocal allosteric regulation with binding partners; compartmentalized responses; dependence of signaling properties upon posttranslational modification; and stoichiometric requirements and/or oligomerization-dependent impact on signaling. The scaffold concept may contribute to novel approaches to the development of effective treatments to hitherto incurable neurodegenerative diseases, through informed modulation of prion protein-ligand interactions.
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Affiliation(s)
- Rafael Linden
- Laboratory of Neurogenesis, Institute of Biophysics, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
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12
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Abstract
Since its discovery the cellular prion protein (encoded by the Prnp gene) has been associated with a large number of functions. The proposed functions rank from basic cellular processes such as cell cycle and survival to neural functions such as behavior and neuroprotection, following a pattern similar to that of Moore's law for electronics. In addition, particular interest is increasing in the participation of Prnp in neurodegeneration. However, in recent years a redefinition of these functions has begun, since examples of previously attributed functions were increasingly re-associated with other proteins. Most of these functions are linked to so-called "Prnp-flanking genes" that are close to the genomic locus of Prnp and which are present in the genome of some Prnp mouse models. In addition, their role in neuroprotection against convulsive insults has been confirmed in recent studies. Lastly, in recent years a large number of models indicating the participation of different domains of the protein in apoptosis have been uncovered. However, after more than 10 years of molecular dissection our view is that the simplest mechanistic model in PrP(C)-mediated cell death should be considered, as Ockham's razor theory suggested.
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Affiliation(s)
- José A del Río
- a Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia (IBEC) , Parc Científic de Barcelona, Barcelona , Spain.,b Department of Cell Biology, Physiology and Inmunology , Facultat de Biologia, Universitat de Barcelona , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Barcelona , Spain
| | - Rosalina Gavín
- a Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia (IBEC) , Parc Científic de Barcelona, Barcelona , Spain.,b Department of Cell Biology, Physiology and Inmunology , Facultat de Biologia, Universitat de Barcelona , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Barcelona , Spain
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13
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Küffer A, Lakkaraju AKK, Mogha A, Petersen SC, Airich K, Doucerain C, Marpakwar R, Bakirci P, Senatore A, Monnard A, Schiavi C, Nuvolone M, Grosshans B, Hornemann S, Bassilana F, Monk KR, Aguzzi A. The prion protein is an agonistic ligand of the G protein-coupled receptor Adgrg6. Nature 2016; 536:464-8. [PMID: 27501152 PMCID: PMC5499706 DOI: 10.1038/nature19312] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 07/19/2016] [Indexed: 12/23/2022]
Abstract
Ablation of the cellular prion protein PrP(C) leads to a chronic demyelinating polyneuropathy affecting Schwann cells. Neuron-restricted expression of PrP(C) prevents the disease, suggesting that PrP(C) acts in trans through an unidentified Schwann cell receptor. Here we show that the cAMP concentration in sciatic nerves from PrP(C)-deficient mice is reduced, suggesting that PrP(C) acts via a G protein-coupled receptor (GPCR). The amino-terminal flexible tail (residues 23-120) of PrP(C) triggered a concentration-dependent increase in cAMP in primary Schwann cells, in the Schwann cell line SW10, and in HEK293T cells overexpressing the GPCR Adgrg6 (also known as Gpr126). By contrast, naive HEK293T cells and HEK293T cells expressing several other GPCRs did not react to the flexible tail, and ablation of Gpr126 from SW10 cells abolished the flexible tail-induced cAMP response. The flexible tail contains a polycationic cluster (KKRPKPG) similar to the GPRGKPG motif of the Gpr126 agonist type-IV collagen. A KKRPKPG-containing PrPC-derived peptide (FT(23-50)) sufficed to induce a Gpr126-dependent cAMP response in cells and mice, and improved myelination in hypomorphic gpr126 mutant zebrafish (Danio rerio). Substitution of the cationic residues with alanines abolished the biological activity of both FT(23-50) and the equivalent type-IV collagen peptide. We conclude that PrP(C) promotes myelin homeostasis through flexible tail-mediated Gpr126 agonism. As well as clarifying the physiological role of PrP(C), these observations are relevant to the pathogenesis of demyelinating polyneuropathies--common debilitating diseases for which there are limited therapeutic options.
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Affiliation(s)
- Alexander Küffer
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Asvin KK Lakkaraju
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Amit Mogha
- Washington University School of Medicine, Department of Developmental Biology and Hope Center for Neurological Disorders, 660 South Euclid Avenue, Campus Box 8103, St. Louis, MO 63110
| | - Sarah C. Petersen
- Washington University School of Medicine, Department of Developmental Biology and Hope Center for Neurological Disorders, 660 South Euclid Avenue, Campus Box 8103, St. Louis, MO 63110
| | - Kristina Airich
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Cédric Doucerain
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | | | - Pamela Bakirci
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Assunta Senatore
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Arnaud Monnard
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Carmen Schiavi
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Mario Nuvolone
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | - Bianka Grosshans
- Novartis Institutes of Biomedical Research, CH-4056 Basel, Switzerland
| | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
| | | | - Kelly R. Monk
- Washington University School of Medicine, Department of Developmental Biology and Hope Center for Neurological Disorders, 660 South Euclid Avenue, Campus Box 8103, St. Louis, MO 63110
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland
- Corresponding author: Adriano Aguzzi, Institute of Neuropathology, University of Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland, Tel: +41-44-255-2107,
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14
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Evans EGB, Pushie MJ, Markham KA, Lee HW, Millhauser GL. Interaction between Prion Protein's Copper-Bound Octarepeat Domain and a Charged C-Terminal Pocket Suggests a Mechanism for N-Terminal Regulation. Structure 2016; 24:1057-67. [PMID: 27265848 DOI: 10.1016/j.str.2016.04.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 11/29/2022]
Abstract
Copper plays a critical role in prion protein (PrP) physiology. Cu(2+) binds with high affinity to the PrP N-terminal octarepeat (OR) domain, and intracellular copper promotes PrP expression. The molecular details of copper coordination within the OR are now well characterized. Here we examine how Cu(2+) influences the interaction between the PrP N-terminal domain and the C-terminal globular domain. Using nuclear magnetic resonance and copper-nitroxide pulsed double electron-electron resonance, with molecular dynamics refinement, we localize the position of Cu(2+) in its high-affinity OR-bound state. Our results reveal an interdomain cis interaction that is stabilized by a conserved, negatively charged pocket of the globular domain. Interestingly, this interaction surface overlaps an epitope recognized by the POM1 antibody, the binding of which drives rapid cerebellar degeneration mediated by the PrP N terminus. The resulting structure suggests that the globular domain regulates the N-terminal domain by binding the Cu(2+)-occupied OR within a complementary pocket.
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Affiliation(s)
- Eric G B Evans
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - M Jake Pushie
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Kate A Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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15
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Kaczmarczyk L, Mende Y, Zevnik B, Jackson WS. Manipulating the Prion Protein Gene Sequence and Expression Levels with CRISPR/Cas9. PLoS One 2016; 11:e0154604. [PMID: 27128441 PMCID: PMC4851410 DOI: 10.1371/journal.pone.0154604] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/16/2016] [Indexed: 01/01/2023] Open
Abstract
The mammalian prion protein (PrP, encoded by Prnp) is most infamous for its central role in prion diseases, invariably fatal neurodegenerative diseases affecting humans, food animals, and animals in the wild. However, PrP is also hypothesized to be an important receptor for toxic protein conformers in Alzheimer's disease, and is associated with other clinically relevant processes such as cancer and stroke. Thus, key insights into important clinical areas, as well as into understanding PrP functions in normal physiology, can be obtained from studying transgenic mouse models and cell culture systems. However, the Prnp locus is difficult to manipulate by homologous recombination, making modifications of the endogenous locus rarely attempted. Fortunately in recent years genome engineering technologies, like TALENs or CRISPR/Cas9 (CC9), have brought exceptional new possibilities for manipulating Prnp. Herein, we present our observations made during systematic experiments with the CC9 system targeting the endogenous mouse Prnp locus, to either modify sequences or to boost PrP expression using CC9-based synergistic activation mediators (SAMs). It is our hope that this information will aid and encourage researchers to implement gene-targeting techniques into their research program.
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Affiliation(s)
- Lech Kaczmarczyk
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ylva Mende
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
| | - Branko Zevnik
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
| | - Walker S. Jackson
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- * E-mail:
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16
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Hiramatsu N, Chiang WC, Kurt TD, Sigurdson CJ, Lin JH. Multiple Mechanisms of Unfolded Protein Response-Induced Cell Death. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1800-8. [PMID: 25956028 DOI: 10.1016/j.ajpath.2015.03.009] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 02/09/2015] [Accepted: 03/26/2015] [Indexed: 12/12/2022]
Abstract
Eukaryotic cells fold and assemble membrane and secreted proteins in the endoplasmic reticulum (ER), before delivery to other cellular compartments or the extracellular environment. Correctly folded proteins are released from the ER, and poorly folded proteins are retained until they achieve stable conformations; irreparably misfolded proteins are targeted for degradation. Diverse pathological insults, such as amino acid mutations, hypoxia, or infection, can overwhelm ER protein quality control, leading to misfolded protein buildup, causing ER stress. To cope with ER stress, eukaryotic cells activate the unfolded protein response (UPR) by increasing levels of ER protein-folding enzymes and chaperones, enhancing the degradation of misfolded proteins, and reducing protein translation. In mammalian cells, three ER transmembrane proteins, inositol-requiring enzyme-1 (IRE1; official name ERN1), PKR-like ER kinase (PERK; official name EIF2AK3), and activating transcription factor-6, control the UPR. The UPR signaling triggers a set of prodeath programs when the cells fail to successfully adapt to ER stress or restore homeostasis. ER stress and UPR signaling are implicated in the pathogenesis of diverse diseases, including neurodegeneration, cancer, diabetes, and inflammation. This review discusses the current understanding in both adaptive and apoptotic responses as well as the molecular mechanisms instigating apoptosis via IRE1 and PERK signaling. We also examine how IRE1 and PERK signaling may be differentially used during neurodegeneration arising in retinitis pigmentosa and prion infection.
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Affiliation(s)
- Nobuhiko Hiramatsu
- Department of Pathology, University of California-San Diego, La Jolla, California
| | - Wei-Chieh Chiang
- Department of Pathology, University of California-San Diego, La Jolla, California
| | - Timothy D Kurt
- Department of Pathology, University of California-San Diego, La Jolla, California
| | | | - Jonathan H Lin
- Department of Pathology, University of California-San Diego, La Jolla, California.
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