1
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Pálmadóttir T, Getachew J, Thacker D, Wallerstein J, Olsson U, Emanuelsson C, Linse S. The Role of α-Synuclein-DNAJB6b Coaggregation in Amyloid Suppression. ACS Chem Neurosci 2025; 16:1883-1897. [PMID: 40304428 PMCID: PMC12100659 DOI: 10.1021/acschemneuro.4c00883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2024] [Revised: 04/16/2025] [Accepted: 04/17/2025] [Indexed: 05/02/2025] Open
Abstract
Chaperones may retard the aggregation of other proteins and increase their solubility. An important goal is a thermodynamic understanding of such an action. Here, the chaperone DNAJB6b (JB6) is found to suppress amyloid formation of the protein α-synuclein (α-syn) leading to a reduced rate of fibril formation and an increase in apparent solubility of α-syn. These findings were reached at mildly acidic pH and with light seeding under conditions where the effect on secondary nucleation is visible. Cryo-transmission electron microscopy (cryo-TEM) imaging reveals that coaggregates of α-syn and JB6 are formed with significantly altered ultrastructure compared to both pure protein fibrils and pure chaperone aggregates. This is further supported by the formation of ThT-negative aggregates and by the depletion of JB6 from solution in the presence of α-syn. The identification of such coaggregates provides a plausible thermodynamic explanation for an increase in α-syn solubility in the presence of JB6; the reduced chemical potential of the chaperone upon formation of coaggregates can compensate for an increased chemical potential of α-syn, and the system as a whole can lower its free energy to sustain an increased free α-syn concentration.
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Affiliation(s)
- Tinna Pálmadóttir
- Biochemistry
and Structural Biology, Lund University, 22100Lund, Sweden
| | - Josef Getachew
- Biochemistry
and Structural Biology, Lund University, 22100Lund, Sweden
| | - Dev Thacker
- Biochemistry
and Structural Biology, Lund University, 22100Lund, Sweden
| | | | - Ulf Olsson
- Physical
Chemistry, Lund University, 22100Lund, Sweden
| | | | - Sara Linse
- Biochemistry
and Structural Biology, Lund University, 22100Lund, Sweden
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2
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Fricke C, Milošević J, Carlsson A, Boyens-Thiele L, Dubackic M, Olsson U, Buell AK, Linse S. On the thermal and chemical stability of DNAJB6b and its globular domains. Biophys Chem 2025; 320-321:107401. [PMID: 39938325 DOI: 10.1016/j.bpc.2025.107401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2024] [Revised: 01/27/2025] [Accepted: 01/30/2025] [Indexed: 02/14/2025]
Abstract
The chaperone DNAJB6b (JB6) plays important roles in increasing amyloid protein solubility and inhibiting amyloid fibril formation, a causative factor for neurodegenerative diseases like Alzheimer's and Parkinson's disease. Insights into the biophysical properties of JB6, including its structure, self-assembly and stability towards denaturation, may enhance the understanding of the physicochemical basis of chaperone action. However, many of the biophysical properties of the chaperone remain elusive. Here, we investigated the structure and stability of JB6 and its domains towards thermal and chemical denaturation using Fourier transform infrared and circular dichroism spectroscopy to examine the thermodynamic properties. Both domains act as independent folding units. We find that the N-terminal domain (NTD) of JB6 is more stable than its C-terminal domain (CTD). Both domains are stabilized in the context of the full-length protein. The intact protein unfolds in a step-wise manner when subjected to a denaturing agent with the CTD unfolding at a lower denaturant concentration than the NTD. The combination of thermal and chemical denaturation followed by differential scanning fluorimetry revealed the enthalpy changes (22.6 and 26.4 kJ mol-1) and heat capacity changes (2.8 and 3.0 kJ/(mol*K)) upon denaturation of NTD alone and of NTD within the full-length protein, respectively. The understanding of JB6's biophysical properties complements the increasing amount of data on JB6's interactions with client proteins, paving the way for further investigation of the mechanism of its cellular function.
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Affiliation(s)
- Celia Fricke
- Lund University, Biochemistry and Structural Biology, Naturvetarv 16, 223 62 Lund, Sweden; Technical University of Denmark, Department of Biotechnology and Biomedicine, Søltofts Pl. 221, 2800 Kongens Lyngby, Denmark
| | - Jelica Milošević
- Lund University, Biochemistry and Structural Biology, Naturvetarv 16, 223 62 Lund, Sweden; University of Belgrade, Faculty of Chemistry, Department of Biochemistry, Studentski trg 12-16, 11158 Belgrade, PAK 105104, Serbia
| | - Andreas Carlsson
- Lund University, Biochemistry and Structural Biology, Naturvetarv 16, 223 62 Lund, Sweden
| | - Lars Boyens-Thiele
- Technical University of Denmark, Department of Biotechnology and Biomedicine, Søltofts Pl. 221, 2800 Kongens Lyngby, Denmark
| | - Marija Dubackic
- Lund University, Physical Chemistry, Naturvetarv 16, 223 62 Lund, Sweden
| | - Ulf Olsson
- Lund University, Physical Chemistry, Naturvetarv 16, 223 62 Lund, Sweden
| | - Alexander K Buell
- Technical University of Denmark, Department of Biotechnology and Biomedicine, Søltofts Pl. 221, 2800 Kongens Lyngby, Denmark
| | - Sara Linse
- Lund University, Biochemistry and Structural Biology, Naturvetarv 16, 223 62 Lund, Sweden.
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3
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Sun KT, Mok SA. Inducers and modulators of protein aggregation in Alzheimer's disease - Critical tools for understanding the foundations of aggregate structures. Neurotherapeutics 2025; 22:e00512. [PMID: 39755501 PMCID: PMC12047394 DOI: 10.1016/j.neurot.2024.e00512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2024] [Revised: 12/02/2024] [Accepted: 12/08/2024] [Indexed: 01/06/2025] Open
Abstract
Amyloidogenic protein aggregation is a pathological hallmark of Alzheimer's Disease (AD). As such, this critical feature of the disease has been instrumental in guiding research on the mechanistic basis of disease, diagnostic biomarkers and preventative and therapeutic treatments. Here we review identified molecular triggers and modulators of aggregation for two of the proteins associated with AD: amyloid beta and tau. We aim to provide an overview of how specific molecular factors can impact aggregation kinetics and aggregate structure to promote disease. Looking toward the future, we highlight some research areas of focus that would accelerate efforts to effectively target protein aggregation in AD.
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Affiliation(s)
- Kerry T Sun
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Sue-Ann Mok
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
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4
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Tai MDS, Ochoa L, Flydal MI, Velasco-Carneros L, Muntaner J, Santiago C, Gamiz-Arco G, Moro F, Jung-Kc K, Gil-Cantero D, Marcilla M, Kallio JP, Muga A, Valpuesta JM, Cuéllar J, Martinez A. Structural recognition and stabilization of tyrosine hydroxylase by the J-domain protein DNAJC12. Nat Commun 2025; 16:2755. [PMID: 40113792 PMCID: PMC11926245 DOI: 10.1038/s41467-025-57733-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/28/2025] [Indexed: 03/22/2025] Open
Abstract
Pathogenic variants of the J-domain protein DNAJC12 cause parkinsonism, which is associated with a defective interaction of DNAJC12 with tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine biosynthesis. In this work, we characterize the formation of the TH:DNAJC12 complex, showing that DNAJC12 binding stabilizes both TH and the variant TH-p.R202H, associated with TH deficiency. This binding delays their time-dependent aggregation in an Hsp70-independent manner, while preserving TH activity and feedback regulatory inhibition by dopamine. DNAJC12 alone barely activates Hsc70 but synergistically stimulates Hsc70 ATPase activity when complexed with TH. Cryo-electron microscopy supported by crosslinking-mass spectroscopy reveals two DNAJC12 monomers bound per TH tetramer, each embracing one of the two regulatory domain dimers, leaving the active sites available for substrate, cofactor and inhibitory dopamine interaction. Our results also reveal the key role of the C-terminal region of DNAJC12 in TH binding, explaining the pathogenic mechanism of the DNAJC12 disease variant p.W175Ter.
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Affiliation(s)
- Mary Dayne S Tai
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Neuro-SysMed Center, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Lissette Ochoa
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Marte I Flydal
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Lorea Velasco-Carneros
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Barrio Sarriena, Leioa, Spain
| | | | - César Santiago
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Gloria Gamiz-Arco
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Neuro-SysMed Center, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Fernando Moro
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Barrio Sarriena, Leioa, Spain
| | - Kunwar Jung-Kc
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Neuro-SysMed Center, Department of Neurology, Haukeland University Hospital, Bergen, Norway
- K.G Jebsen Center for Translational Research in Parkinson's Disease, University of Bergen, Bergen, Norway
| | | | | | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Arturo Muga
- Instituto Biofisika (UPV/EHU, CSIC) and Departamento de Bioquímica y Biología Molecular, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Barrio Sarriena, Leioa, Spain
| | - José María Valpuesta
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
- Unidad de Nanobiotecnología, CNB-CSIC-IMDEA Nanociencia Associated Unit, Madrid, Spain.
| | - Jorge Cuéllar
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Bergen, Norway.
- Neuro-SysMed Center, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
- K.G Jebsen Center for Translational Research in Parkinson's Disease, University of Bergen, Bergen, Norway.
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5
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Jami KM, Farb DC, Osumi KM, Shafer CC, Criscione S, Murray DT. Small heat shock protein HSPB8 interacts with a pre-fibrillar TDP43 low complexity domain species to delay fibril formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.28.635368. [PMID: 39974920 PMCID: PMC11838303 DOI: 10.1101/2025.01.28.635368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/21/2025]
Abstract
The loss of cellular proteostasis through aberrant stress granule formation is implicated in neurodegenerative diseases. Stress granules are formed by biomolecular condensation involving protein-protein and protein-RNA interactions. These assemblies are protective, but can rigidify, leading to amyloid-like fibril formation, a hallmark of the disease pathology. Key proteins dictating stress granule formation and disassembly, such as TDP43, contain low-complexity (LC) domains that drive fibril formation. HSPB8, a small heat shock protein, plays a critical role modulating stress granule fluidity, preventing aggregation and promoting degradation of misfolded proteins. We examined the interaction between HSPB8 and the TDP43 LC using thioflavin T (ThT) and fluorescence polarization (FP) aggregation assays, fluorescence microscopy and photobleaching experiments, and crosslinking mass spectrometry (XL-MS). Our results indicate that HSPB8 delays TDP43 LC aggregation through domain-specific interactions with fibril nucleating species, without affecting fibril elongation rates. These findings provide mechanistic insight into how ATP-independent chaperones mediate LC domain aggregation and provide a basis for investigating how the TDP43 LC subverts chaperone activity in neurodegenerative disease.
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Affiliation(s)
- Khaled M. Jami
- Department of Chemistry, University of California, Davis, California, United States of America
| | - Daniel C. Farb
- Department of Chemistry, University of California, Davis, California, United States of America
| | - Kayla M. Osumi
- Department of Chemistry, University of California, Davis, California, United States of America
| | - Catelynn C. Shafer
- Department of Chemistry, University of California, Davis, California, United States of America
| | - Sophie Criscione
- Department of Chemistry, University of California, Davis, California, United States of America
| | - Dylan T. Murray
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
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6
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Ghosh S, Clore GM. Decoding chaperone complexes: Insights from NMR spectroscopy. BIOPHYSICS REVIEWS 2024; 5:041308. [PMID: 39679202 PMCID: PMC11637561 DOI: 10.1063/5.0233299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2024] [Accepted: 11/22/2024] [Indexed: 12/17/2024]
Abstract
Molecular chaperones play a key role in protein homeostasis by preventing misfolding and aggregation, assisting in proper protein folding, and sometimes even disaggregating formed aggregates. Chaperones achieve this through a range of transient weak protein-protein interactions, which are difficult to study using traditional structural and biophysical techniques. Nuclear magnetic resonance (NMR) spectroscopy, however, is well-suited for studying such dynamic states and interactions. A wide range of NMR experiments have been particularly valuable in understanding the mechanisms of chaperone function, as they can characterize disordered protein structures, detect weak and nonspecific interactions involving sparsely populated states, and probe the conformational dynamics of proteins and their complexes. Recent advances in NMR have significantly enhanced our knowledge of chaperone mechanisms, especially chaperone-client interactions, despite the inherent challenges posed by the flexibility and complexity of these systems. In this review, we highlight contributions of NMR to the chaperone field, focusing on the work carried out in our laboratory, which have provided insights into how chaperones maintain function within the cellular environment and interact with various protein substrates.
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Affiliation(s)
- Shreya Ghosh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
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7
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Wang D, Xiao J, Du Y, Zhang L, Qin X. Abnormally High Expression of DNAJB6 Accelerates Malignant Progression of Lung Adenocarcinoma. Biomedicines 2024; 12:1981. [PMID: 39335495 PMCID: PMC11429285 DOI: 10.3390/biomedicines12091981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 07/31/2024] [Accepted: 08/09/2024] [Indexed: 09/30/2024] Open
Abstract
DNAJB6, a major member of the DNAJ/HSP40 family, plays an important role in tumor development. We explored the effect of DNAJB6 expression on the prognosis of patients and its biological role in lung adenocarcinoma (LUAD). mRNA and clinical data were obtained from The Cancer Genome Atlas (TCGA). Enriched pathways were determined by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A nomogram incorporating DNAJB6 and three clinical features was constructed to predict the survival rate. DNAJB6 expression and function in LUAD were explored using immunohistochemistry, Western blotting, proliferation, cell cycle analysis, RNA sequencing, and xenograft tumor assays. DNAJB6 mRNA levels were elevated in the LUAD-TCGA dataset. DNAJB6 protein levels were higher in LUAD tumor tissues than in normal tissues. A high DNAJB6 level was an independent risk factor for poor prognosis in patients with LUAD. The proportion of tumor-infiltrating immune cells significantly differed between high and low DNAJB6 expression. DNAJB6 was associated with cell cycle pathways; therefore, its knockdown induced G2/M cell cycle arrest and inhibited LUAD cell proliferation. This is the first report of the DNAJB6 requirement for LUAD cell proliferation and its potentially crucial role in LUAD prognosis.
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Affiliation(s)
- Di Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Jiayu Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Yang Du
- Department of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Li Zhang
- Department of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Xuzhen Qin
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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8
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Peng J, Zaman M, Yang S, Huang Y, Yarbro J, Wang Z, Liu D, Soliman H, Hemphill A, Harvey S, Pruett-Miller S, Stewart V, Tanwar A, Kalathur R, Grace C, Turk M, Chittori S, Jiao Y, Wu Z, High A, Wang X, Serrano G, Beach T, Yu G, Yang Y, Chen PC. Midkine Attenuates Aβ Fibril Assembly and AmyloidPlaque Formation. RESEARCH SQUARE 2024:rs.3.rs-4361125. [PMID: 38883748 PMCID: PMC11177971 DOI: 10.21203/rs.3.rs-4361125/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Proteomic profiling of Alzheimer's disease (AD) brains has identified numerous understudied proteins, including midkine (MDK), that are highly upregulated and correlated with Aβ since the early disease stage, but their roles in disease progression are not fully understood. Here we present that MDK attenuates Aβ assembly and influences amyloid formation in the 5xFAD amyloidosis mouse model. MDK protein mitigates fibril formation of both Aβ40 and Aβ42 peptides in Thioflavin T fluorescence assay, circular dichroism, negative stain electron microscopy, and NMR analysis. Knockout of Mdkgene in 5xFAD increases amyloid formation and microglial activation. Further comprehensive mass spectrometry-based profiling of whole proteome and aggregated proteome in these mouse models indicates significant accumulation of Aβ and Aβ-correlated proteins, along with microglial components. Thus, our structural and mouse model studies reveal a protective role of MDK in counteracting amyloid pathology in Alzheimer's disease.
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Affiliation(s)
| | | | - Shu Yang
- St Jude Children's Research Hospital
| | - Ya Huang
- St Jude Children's Research Hospital
| | | | - Zhen Wang
- St Jude Children's Research Hospital
| | | | | | | | | | | | | | | | | | | | | | | | - Yun Jiao
- St Jude Children's Research Hospital
| | | | | | | | | | | | - Gang Yu
- University of Texas Southwestern Medical Center
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9
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Wei J, Meisl G, Dear A, Oosterhuis M, Melki R, Emanuelsson C, Linse S, Knowles TPJ. Kinetic models reveal the interplay of protein production and aggregation. Chem Sci 2024; 15:8430-8442. [PMID: 38846392 PMCID: PMC11151821 DOI: 10.1039/d4sc00088a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/29/2024] [Indexed: 06/09/2024] Open
Abstract
Protein aggregation is a key process in the development of many neurodegenerative disorders, including dementias such as Alzheimer's disease. Significant progress has been made in understanding the molecular mechanisms of aggregate formation in pure buffer systems, much of which was enabled by the development of integrated rate laws that allowed for mechanistic analysis of aggregation kinetics. However, in order to translate these findings into disease-relevant conclusions and to make predictions about the effect of potential alterations to the aggregation reactions by the addition of putative inhibitors, the current models need to be extended to account for the altered situation encountered in living systems. In particular, in vivo, the total protein concentrations typically do not remain constant and aggregation-prone monomers are constantly being produced but also degraded by cells. Here, we build a theoretical model that explicitly takes into account monomer production, derive integrated rate laws and discuss the resulting scaling laws and limiting behaviours. We demonstrate that our models are suited for the aggregation-prone Huntington's disease-associated peptide HttQ45 utilizing a system for continuous in situ monomer production and the aggregation of the tumour suppressor protein P53. The aggregation-prone HttQ45 monomer was produced through enzymatic cleavage of a larger construct in which a fused protein domain served as an internal inhibitor. For P53, only the unfolded monomers form aggregates, making the unfolding a rate-limiting step which constitutes a source of aggregation-prone monomers. The new model opens up possibilities for a quantitative description of aggregation in living systems, allowing for example the modelling of inhibitors of aggregation in a dynamic environment of continuous protein synthesis.
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Affiliation(s)
- Jiapeng Wei
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Georg Meisl
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Alexander Dear
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
- Department of Biochemistry and Structural Biology, Lund University SE22100 Lund Sweden
| | - Matthijs Oosterhuis
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University Sweden
| | - Ronald Melki
- Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS 18 Route du Panorama, Fontenay-Aux-Roses cedex 92265 France
| | - Cecilia Emanuelsson
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University Sweden
| | - Sara Linse
- Department of Biochemistry and Structural Biology, Lund University Lund Sweden
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
- Cavendish Laboratory, University of Cambridge J J Thomson Avenue CB3 0HE UK
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10
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Dear AJ, Teng X, Ball SR, Lewin J, Horne RI, Clow D, Stevenson A, Harper N, Yahya K, Yang X, Brewerton SC, Thomson J, Michaels TCT, Linse S, Knowles TPJ, Habchi J, Meisl G. Molecular mechanism of α-synuclein aggregation on lipid membranes revealed. Chem Sci 2024; 15:7229-7242. [PMID: 38756798 PMCID: PMC11095391 DOI: 10.1039/d3sc05661a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/14/2024] [Indexed: 05/18/2024] Open
Abstract
The central hallmark of Parkinson's disease pathology is the aggregation of the α-synuclein protein, which, in its healthy form, is associated with lipid membranes. Purified monomeric α-synuclein is relatively stable in vitro, but its aggregation can be triggered by the presence of lipid vesicles. Despite this central importance of lipids in the context of α-synuclein aggregation, their detailed mechanistic role in this process has not been established to date. Here, we use chemical kinetics to develop a mechanistic model that is able to globally describe the aggregation behaviour of α-synuclein in the presence of DMPS lipid vesicles, across a range of lipid and protein concentrations. Through the application of our kinetic model to experimental data, we find that the reaction is a co-aggregation process involving both protein and lipids and that lipids promote aggregation as much by enabling fibril elongation as by enabling their initial formation. Moreover, we find that the primary nucleation of lipid-protein co-aggregates takes place not on the surface of lipid vesicles in bulk solution but at the air-water and/or plate interfaces, where lipids and proteins are likely adsorbed. Our model forms the basis for mechanistic insights, also in other lipid-protein co-aggregation systems, which will be crucial in the rational design of drugs that inhibit aggregate formation and act at the key points in the α-synuclein aggregation cascade.
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Affiliation(s)
- Alexander J Dear
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Xiangyu Teng
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Sarah R Ball
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Joshua Lewin
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Robert I Horne
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Daniel Clow
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Alisdair Stevenson
- Department of Biology, Institute of Biochemistry, ETH Zurich Otto Stern Weg 3 8093 Zurich Switzerland
- Bringing Materials to Life Initiative, ETH Zurich Switzerland
| | - Natasha Harper
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Kim Yahya
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Xiaoting Yang
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Suzanne C Brewerton
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - John Thomson
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Thomas C T Michaels
- Department of Biology, Institute of Biochemistry, ETH Zurich Otto Stern Weg 3 8093 Zurich Switzerland
- Bringing Materials to Life Initiative, ETH Zurich Switzerland
| | - Sara Linse
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
- Biochemistry and Structural Biology, Lund University Lund Sweden
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge Cambridge UK
- Cavendish Laboratory, University of Cambridge Cambridge UK
| | - Johnny Habchi
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
| | - Georg Meisl
- WaveBreak Therapeutics Ltd, Chemistry of Health Lensfield Road Cambridge CB2 1EW UK
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11
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Carlsson A, Axell E, Emanuelsson C, Olsson U, Linse S. The Ability of DNAJB6b to Suppress Amyloid Formation Depends on the Chaperone Aggregation State. ACS Chem Neurosci 2024; 15:1732-1737. [PMID: 38640082 PMCID: PMC11066835 DOI: 10.1021/acschemneuro.4c00120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024] Open
Abstract
For many chaperones, a propensity to self-assemble correlates with function. The highly efficient amyloid suppressing chaperone DNAJB6b has been reported to oligomerize. A key question is whether the DNAJB6b self-assemblies or their subunits are active units in the suppression of amyloid formation. Here, we address this question using a nonmodified chaperone. We use the well-established aggregation kinetics of the amyloid β 42 peptide (Aβ42) as a readout of the amyloid suppression efficiency. The experimental setup relies on the slow dissociation of DNAJB6b assemblies upon dilution. We find that the dissociation of the chaperone assemblies correlates with its ability to suppress fibril formation. Thus, the data show that the subunits of DNAJB6b assemblies rather than the large oligomers are the active forms in amyloid suppression. Our results provide insights into how DNAJB6b operates as a chaperone and illustrate the importance of established assembly equilibria and dissociation rates for the design of kinetic experiments.
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Affiliation(s)
- Andreas Carlsson
- Lund
University, Biochemistry and Structural Biology, Lund, Naturvetarvägen 16, 223 62, Sweden
| | - Emil Axell
- Lund
University, Biochemistry and Structural Biology, Lund, Naturvetarvägen 16, 223 62, Sweden
| | - Cecilia Emanuelsson
- Lund
University, Biochemistry and Structural Biology, Lund, Naturvetarvägen 16, 223 62, Sweden
| | - Ulf Olsson
- Lund
University, Physical Chemistry, Lund, Naturvetarvägen 16, 223 62, Sweden
| | - Sara Linse
- Lund
University, Biochemistry and Structural Biology, Lund, Naturvetarvägen 16, 223 62, Sweden
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12
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Heesink G, van den Oetelaar MCM, Semerdzhiev SA, Ottmann C, Brunsveld L, Blum C, Claessens MMAE. 14-3-3τ as a Modulator of Early α-Synuclein Multimerization and Amyloid Formation. ACS Chem Neurosci 2024; 15:1926-1936. [PMID: 38635928 PMCID: PMC11066837 DOI: 10.1021/acschemneuro.4c00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/20/2024] Open
Abstract
The aggregation of α-synuclein (αS) plays a key role in Parkinson's disease (PD) etiology. While the onset of PD is age-related, the cellular quality control system appears to regulate αS aggregation throughout most human life. Intriguingly, the protein 14-3-3τ has been demonstrated to delay αS aggregation and the onset of PD in various models. However, the molecular mechanisms behind this delay remain elusive. Our study confirms the delay in αS aggregation by 14-3-3τ, unveiling a concentration-dependent relation. Utilizing microscale thermophoresis (MST) and single-molecule burst analysis, we quantified the early αS multimers and concluded that these multimers exhibit properties that classify them as nanoscale condensates that form in a cooperative process, preceding the critical nucleus for fibril formation. Significantly, the αS multimer formation mechanism changes dramatically in the presence of scaffold protein 14-3-3τ. Our data modeling suggests that 14-3-3τ modulates the multimerization process, leading to the creation of mixed multimers or co-condensates, comprising both αS and 14-3-3τ. These mixed multimers form in a noncooperative process. They are smaller, more numerous, and distinctively not on the pathway to amyloid formation. Importantly, 14-3-3τ thus acts in the very early stage of αS multimerization, ensuring that αS does not aggregate but remains soluble and functional. This offers long-sought novel entries for the pharmacological modulation of PD.
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Affiliation(s)
- Gobert Heesink
- Nanobiophysics,
Faculty of Science and Technology, MESA + Institute for Nanotechnology
and Technical Medical Centre, University
of Twente, Enschede 7500 AE, The Netherlands
| | - Maxime C. M. van den Oetelaar
- Laboratory
of Chemical Biology, Department of Biomedical Engineering and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Slav A. Semerdzhiev
- Nanobiophysics,
Faculty of Science and Technology, MESA + Institute for Nanotechnology
and Technical Medical Centre, University
of Twente, Enschede 7500 AE, The Netherlands
| | - Christian Ottmann
- Laboratory
of Chemical Biology, Department of Biomedical Engineering and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Luc Brunsveld
- Laboratory
of Chemical Biology, Department of Biomedical Engineering and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Christian Blum
- Nanobiophysics,
Faculty of Science and Technology, MESA + Institute for Nanotechnology
and Technical Medical Centre, University
of Twente, Enschede 7500 AE, The Netherlands
| | - Mireille M. A. E. Claessens
- Nanobiophysics,
Faculty of Science and Technology, MESA + Institute for Nanotechnology
and Technical Medical Centre, University
of Twente, Enschede 7500 AE, The Netherlands
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13
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Kinger S, Jagtap YA, Kumar P, Choudhary A, Prasad A, Prajapati VK, Kumar A, Mehta G, Mishra A. Proteostasis in neurodegenerative diseases. Adv Clin Chem 2024; 121:270-333. [PMID: 38797543 DOI: 10.1016/bs.acc.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Proteostasis is essential for normal function of proteins and vital for cellular health and survival. Proteostasis encompasses all stages in the "life" of a protein, that is, from translation to functional performance and, ultimately, to degradation. Proteins need native conformations for function and in the presence of multiple types of stress, their misfolding and aggregation can occur. A coordinated network of proteins is at the core of proteostasis in cells. Among these, chaperones are required for maintaining the integrity of protein conformations by preventing misfolding and aggregation and guide those with abnormal conformation to degradation. The ubiquitin-proteasome system (UPS) and autophagy are major cellular pathways for degrading proteins. Although failure or decreased functioning of components of this network can lead to proteotoxicity and disease, like neuron degenerative diseases, underlying factors are not completely understood. Accumulating misfolded and aggregated proteins are considered major pathomechanisms of neurodegeneration. In this chapter, we have described the components of three major branches required for proteostasis-chaperones, UPS and autophagy, the mechanistic basis of their function, and their potential for protection against various neurodegenerative conditions, like Alzheimer's, Parkinson's, and Huntington's disease. The modulation of various proteostasis network proteins, like chaperones, E3 ubiquitin ligases, proteasome, and autophagy-associated proteins as therapeutic targets by small molecules as well as new and unconventional approaches, shows promise.
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Affiliation(s)
- Sumit Kinger
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Yuvraj Anandrao Jagtap
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Prashant Kumar
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Akash Choudhary
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Amit Prasad
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, Madhya Pradesh, India
| | - Gunjan Mehta
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India.
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14
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Kumar R, Le Marchand T, Adam L, Bobrovs R, Chen G, Fridmanis J, Kronqvist N, Biverstål H, Jaudzems K, Johansson J, Pintacuda G, Abelein A. Identification of potential aggregation hotspots on Aβ42 fibrils blocked by the anti-amyloid chaperone-like BRICHOS domain. Nat Commun 2024; 15:965. [PMID: 38302480 PMCID: PMC10834949 DOI: 10.1038/s41467-024-45192-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024] Open
Abstract
Protein misfolding can generate toxic intermediates, which underlies several devastating diseases, such as Alzheimer's disease (AD). The surface of AD-associated amyloid-β peptide (Aβ) fibrils has been suggested to act as a catalyzer for self-replication and generation of potentially toxic species. Specifically tailored molecular chaperones, such as the BRICHOS protein domain, were shown to bind to amyloid fibrils and break this autocatalytic cycle. Here, we identify a site on the Aβ42 fibril surface, consisting of three C-terminal β-strands and particularly the solvent-exposed β-strand stretching from residues 26-28, which is efficiently sensed by a designed variant of Bri2 BRICHOS. Remarkably, while only a low amount of BRICHOS binds to Aβ42 fibrils, fibril-catalyzed nucleation processes are effectively prevented, suggesting that the identified site acts as a catalytic aggregation hotspot, which can specifically be blocked by BRICHOS. Hence, these findings provide an understanding how toxic nucleation events can be targeted by molecular chaperones.
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Affiliation(s)
- Rakesh Kumar
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Tanguy Le Marchand
- Université de Lyon, Centre de Resonance Magnétique Nucléaire (CRMN) à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, UCB Lyon 1), 69100, Villeurbanne, France
| | - Laurène Adam
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Raitis Bobrovs
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Gefei Chen
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Jēkabs Fridmanis
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Nina Kronqvist
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Henrik Biverstål
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Kristaps Jaudzems
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Jan Johansson
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Guido Pintacuda
- Université de Lyon, Centre de Resonance Magnétique Nucléaire (CRMN) à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, UCB Lyon 1), 69100, Villeurbanne, France
| | - Axel Abelein
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden.
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15
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Esquivel AR, Hill SE, Blair LJ. DnaJs are enriched in tau regulators. Int J Biol Macromol 2023; 253:127486. [PMID: 37852393 PMCID: PMC10842427 DOI: 10.1016/j.ijbiomac.2023.127486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/09/2023] [Accepted: 10/15/2023] [Indexed: 10/20/2023]
Abstract
The aberrant accumulation of tau protein is implicated as a pathogenic factor in many neurodegenerative diseases. Tau seeding may underlie its predictable spread in these diseases. Molecular chaperones can modulate tau pathology, but their effects have mainly been studied in isolation. This study employed a semi-high throughput assay to identify molecular chaperones influencing tau seeding using Tau RD P301S FRET Biosensor cells, which express a portion of tau containing the frontotemporal dementia-related P301S tau mutation fused to a FRET biosensor. Approximately fifty chaperones from five major families were screened using live cell imaging to monitor FRET-positive tau seeding. Among the tested chaperones, five exhibited significant effects on tau in the primary screen. Notably, three of these were from the DnaJ family. In subsequent studies, overexpression of DnaJA2, DnaJB1, and DnaJB6b resulted in significant reductions in tau levels. Knockdown experiments by shRNA revealed an inverse correlation between DnaJB1 and DnaJB6b with tau levels. DnaJB6b overexpression, specifically, reduced total tau levels in a cellular model with a pre-existing pool of tau, partially through enhanced proteasomal degradation. Further, DnaJB6b interacted with tau complexes. These findings highlight the potent chaperone activity within the DnaJ family, particularly DnaJB6b, towards tau.
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Affiliation(s)
- Abigail R Esquivel
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Shannon E Hill
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Laura J Blair
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA; Research Service, James A Haley Veterans Hospital, 13000 Bruce B Downs Blvd, Tampa, FL 33612, USA.
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16
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Kristoffersen K, Hansen KH, Andreasen M. Differential Effects of Lipid Bilayers on αPSM Peptide Functional Amyloid Formation. Int J Mol Sci 2023; 25:102. [PMID: 38203273 PMCID: PMC10779341 DOI: 10.3390/ijms25010102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/16/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Phenol-soluble modulins (PSMs) are key virulence factors of S. aureus, and they comprise the structural scaffold of biofilm as they self-assemble into functional amyloids. They have been shown to interact with cell membranes as they display toxicity towards human cells through cell lysis, with αPSM3 being the most cytotoxic. In addition to causing cell lysis in mammalian cells, PSMs have also been shown to interact with bacterial cell membranes through antimicrobial effects. Here, we present a study on the effects of lipid bilayers on the aggregation mechanism of αPSM using chemical kinetics to study the effects of lipid vesicles on the aggregation kinetics and using circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) to investigate the corresponding secondary structure of the aggregates. We found that the effects of lipid bilayers on αPSM aggregation were not homogeneous between lipid type and αPSM peptides, although none of the lipids caused changes in the dominating aggregation mechanism. In the case of αPSM3, all types of lipids slowed down aggregation to a varying degree, with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) having the most pronounced effect. For αPSM1, lipids had opposite effects, where DOPC decelerated aggregation and lipopolysaccharide (LPS) accelerated the aggregation, while 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG) had no effect. For αPSM4, both DOPG and LPS accelerated the aggregation, but only at high concentration, while DOPC showed no effect. None of the lipids was capable of inducing aggregation of αPSM2. Our data reveal a complex interaction pattern between PSMs peptides and lipid bilayers that causes changes in the aggregation kinetics by affecting different kinetic parameters along with only subtle changes in morphology.
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Affiliation(s)
| | | | - Maria Andreasen
- Department of Biomedicine, Aarhus University, Willhelm Meyer’s Allé 3, 8000 Aarhus, Denmark
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17
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Chang YL, Yang CC, Huang YY, Chen YA, Yang CW, Liao CY, Li H, Wu CS, Lin CH, Teng SC. The HSP40 family chaperone isoform DNAJB6b prevents neuronal cells from tau aggregation. BMC Biol 2023; 21:293. [PMID: 38110916 PMCID: PMC10729500 DOI: 10.1186/s12915-023-01798-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 12/05/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disorder with clinical presentations of progressive cognitive and memory deterioration. The pathologic hallmarks of AD include tau neurofibrillary tangles and amyloid plaque depositions in the hippocampus and associated neocortex. The neuronal aggregated tau observed in AD cells suggests that the protein folding problem is a major cause of AD. J-domain-containing proteins (JDPs) are the largest family of cochaperones, which play a vital role in specifying and directing HSP70 chaperone functions. JDPs bind substrates and deliver them to HSP70. The association of JDP and HSP70 opens the substrate-binding domain of HSP70 to help the loading of the clients. However, in the initial HSP70 cycle, which JDP delivers tau to the HSP70 system in neuronal cells remains unclear. RESULTS We screened the requirement of a diverse panel of JDPs for preventing tau aggregation in the human neuroblastoma cell line SH-SY5Y by a filter retardation method. Interestingly, knockdown of DNAJB6, one of the JDPs, displayed tau aggregation and overexpression of DNAJB6b, one of the isoforms generated from the DNAJB6 gene by alternative splicing, reduced tau aggregation. Further, the tau bimolecular fluorescence complementation assay confirmed the DNAJB6b-dependent tau clearance. The co-immunoprecipitation and the proximity ligation assay demonstrated the protein-protein interaction between tau and the chaperone-cochaperone complex. The J-domain of DNAJB6b was critical for preventing tau aggregation. Moreover, reduced DNAJB6 expression and increased tau aggregation were detected in an age-dependent manner in immunohistochemical analysis of the hippocampus tissues of a mouse model of tau pathology. CONCLUSIONS In summary, downregulation of DNAJB6b increases the insoluble form of tau, while overexpression of DNAJB6b reduces tau aggregation. Moreover, DNAJB6b associates with tau. Therefore, this study reveals that DNAJB6b is a direct sensor for its client tau in the HSP70 folding system in neuronal cells, thus helping to prevent AD.
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Affiliation(s)
- Ya-Lan Chang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chan-Chih Yang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Yun-Yu Huang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Yi-An Chen
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chia-Wei Yang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chia-Yu Liao
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Hsun Li
- Department of Neurology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, 10051, Taiwan
| | - Ching-Shyi Wu
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chin-Hsien Lin
- Department of Neurology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, 10051, Taiwan.
| | - Shu-Chun Teng
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan.
- Center of Precision Medicine, National Taiwan University, Taipei, 10051, Taiwan.
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18
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Abayev-Avraham M, Salzberg Y, Gliksberg D, Oren-Suissa M, Rosenzweig R. DNAJB6 mutants display toxic gain of function through unregulated interaction with Hsp70 chaperones. Nat Commun 2023; 14:7066. [PMID: 37923706 PMCID: PMC10624832 DOI: 10.1038/s41467-023-42735-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023] Open
Abstract
Molecular chaperones are essential cellular components that aid in protein folding and preventing the abnormal aggregation of disease-associated proteins. Mutations in one such chaperone, DNAJB6, were identified in patients with LGMDD1, a dominant autosomal disorder characterized by myofibrillar degeneration and accumulations of aggregated protein within myocytes. The molecular mechanisms through which such mutations cause this dysfunction, however, are not well understood. Here we employ a combination of solution NMR and biochemical assays to investigate the structural and functional changes in LGMDD1 mutants of DNAJB6. Surprisingly, we find that DNAJB6 disease mutants show no reduction in their aggregation-prevention activity in vitro, and instead differ structurally from the WT protein, affecting their interaction with Hsp70 chaperones. While WT DNAJB6 contains a helical element regulating its ability to bind and activate Hsp70, in LGMDD1 disease mutants this regulation is disrupted. These variants can thus recruit and hyperactivate Hsp70 chaperones in an unregulated manner, depleting Hsp70 levels in myocytes, and resulting in the disruption of proteostasis. Interfering with DNAJB6-Hsp70 binding, however, reverses the disease phenotype, suggesting future therapeutic avenues for LGMDD1.
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Affiliation(s)
- Meital Abayev-Avraham
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Yehuda Salzberg
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Dar Gliksberg
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Meital Oren-Suissa
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Rina Rosenzweig
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel.
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19
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Österlund N, Frankel R, Carlsson A, Thacker D, Karlsson M, Matus V, Gräslund A, Emanuelsson C, Linse S. The C-terminal domain of the antiamyloid chaperone DNAJB6 binds to amyloid-β peptide fibrils and inhibits secondary nucleation. J Biol Chem 2023; 299:105317. [PMID: 37797698 PMCID: PMC10641233 DOI: 10.1016/j.jbc.2023.105317] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 09/13/2023] [Accepted: 09/18/2023] [Indexed: 10/07/2023] Open
Abstract
The DNAJB6 chaperone inhibits fibril formation of aggregation-prone client peptides through interaction with aggregated and oligomeric forms of the amyloid peptides. Here, we studied the role of its C-terminal domain (CTD) using constructs comprising either the entire CTD or the first two or all four of the CTD β-strands grafted onto a scaffold protein. Each construct was expressed as WT and as a variant with alanines replacing five highly conserved and functionally important serine and threonine residues in the first β-strand. We investigated the stability, oligomerization, antiamyloid activity, and affinity for amyloid-β (Aβ42) species using optical spectroscopy, native mass spectrometry, chemical crosslinking, and surface plasmon resonance technology. While DNAJB6 forms large and polydisperse oligomers, CTD was found to form only monomers, dimers, and tetramers of low affinity. Kinetic analyses showed a shift in inhibition mechanism. Whereas full-length DNAJB6 activity is dependent on the serine and threonine residues and efficiently inhibits primary and secondary nucleation, all CTD constructs inhibit secondary nucleation only, independently of the serine and threonine residues, although their dimerization and thermal stabilities are reduced by alanine substitution. While the full-length DNAJB6 inhibition of primary nucleation is related to its propensity to form coaggregates with Aβ, the CTD constructs instead bind to Aβ42 fibrils, which affects the nucleation events at the fibril surface. The retardation of secondary nucleation by DNAJB6 can thus be ascribed to the first two β-strands of its CTD, whereas the inhibition of primary nucleation is dependent on the entire protein or regions outside the CTD.
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Affiliation(s)
- Nicklas Österlund
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| | - Rebecca Frankel
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Andreas Carlsson
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Dev Thacker
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Maja Karlsson
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Vanessa Matus
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Cecilia Emanuelsson
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden
| | - Sara Linse
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden.
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20
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Khaled M, Rönnbäck I, Ilag LL, Gräslund A, Strodel B, Österlund N. A Hairpin Motif in the Amyloid-β Peptide Is Important for Formation of Disease-Related Oligomers. J Am Chem Soc 2023; 145:18340-18354. [PMID: 37555670 PMCID: PMC10450692 DOI: 10.1021/jacs.3c03980] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Indexed: 08/10/2023]
Abstract
The amyloid-β (Aβ) peptide is associated with the development of Alzheimer's disease and is known to form highly neurotoxic prefibrillar oligomeric aggregates, which are difficult to study due to their transient, low-abundance, and heterogeneous nature. To obtain high-resolution information about oligomer structure and dynamics as well as relative populations of assembly states, we here employ a combination of native ion mobility mass spectrometry and molecular dynamics simulations. We find that the formation of Aβ oligomers is dependent on the presence of a specific β-hairpin motif in the peptide sequence. Oligomers initially grow spherically but start to form extended linear aggregates at oligomeric states larger than those of the tetramer. The population of the extended oligomers could be notably increased by introducing an intramolecular disulfide bond, which prearranges the peptide in the hairpin conformation, thereby promoting oligomeric structures but preventing conversion into mature fibrils. Conversely, truncating one of the β-strand-forming segments of Aβ decreased the hairpin propensity of the peptide and thus decreased the oligomer population, removed the formation of extended oligomers entirely, and decreased the aggregation propensity of the peptide. We thus propose that the observed extended oligomer state is related to the formation of an antiparallel sheet state, which then nucleates into the amyloid state. These studies provide increased mechanistic understanding of the earliest steps in Aβ aggregation and suggest that inhibition of Aβ folding into the hairpin conformation could be a viable strategy for reducing the amount of toxic oligomers.
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Affiliation(s)
- Mohammed Khaled
- Institute
of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Isabel Rönnbäck
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Leopold L. Ilag
- Department
of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden
| | - Astrid Gräslund
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Birgit Strodel
- Institute
of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institute
of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Nicklas Österlund
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
- Department
of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden
- Department
of Microbiology, Tumor and Cell Biology, Karolinska Institutet − Biomedicum, 171 65 Solna, Sweden
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21
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Chatterjee T, Das G, Chatterjee BK, Ghosh S, Chakrabarti P. The Role of Protein- L-isoaspartyl Methyltransferase (PIMT) in the Suppression of Toxicity of the Oligomeric Form of Aβ42, in Addition to the Inhibition of Its Fibrillization. ACS Chem Neurosci 2023; 14:2888-2901. [PMID: 37535852 DOI: 10.1021/acschemneuro.3c00281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023] Open
Abstract
The oligomeric form of amyloid-β peptide (Aβ42) plays a crucial role in the pathogenesis of Alzheimer's disease (AD) and is responsible for cognitive deficits. The soluble oligomers are believed to be more toxic compared to the fibril form. Protein-L-isoaspartyl methyltransferase (PIMT) is a repair enzyme that converts aberrant isoAsp residues, formed spontaneously on isomerization of normal Asp and Asn residues, back to typical Asp. It was shown to inhibit the fibrillization of Aβ42 (containing three Asp residues), and here, we investigate its effect on the size, conformation, and toxicity of Aβ42 oligomers (AβO). Far-UV CD indicated a shift in the conformational feature of AβOs from the random coil to β-sheet in the presence of PIMT. Binding of bis-ANS to different AβOs (obtained using different concentrations of Aβ42 monomer) indicated the correlation of size of oligomers to hydrophobicity: the smallest AβO having the highest hydrophobicity is the most toxic. Dynamic light scattering showed an increase in size of AβO with the addition of PIMT, a contrasting role to that on Aβ fibril. Assays using PC12-derived neurons showed the neuroprotective role of PIMT against AβO-induced toxicity. Furthermore, we have elaborated on the molecular mechanism of the antifibrillar action of PIMT and how this function is correlated with its enzymatic activity. PIMT has a more pronounced effect on AβO as compared to a small heat shock protein, pointing to its importance for the amelioration of the adverse effect of both Aβ42 oligomers and fibrils.
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Affiliation(s)
- Tanaya Chatterjee
- Department of Biochemistry, Bose Institute, P1/12 CIT Scheme VIIM, Kolkata 700054, India
| | - Gaurav Das
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Barun K Chatterjee
- Department of Physics, Bose Institute, 93/1 A.P.C. Road, Kolkata 700054, India
| | - Surajit Ghosh
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Pinak Chakrabarti
- Department of Biochemistry, Bose Institute, P1/12 CIT Scheme VIIM, Kolkata 700054, India
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22
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Carlsson A, Olsson U, Linse S. On the micelle formation of DNAJB6b. QRB DISCOVERY 2023; 4:e6. [PMID: 37593255 PMCID: PMC10427797 DOI: 10.1017/qrd.2023.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/22/2023] [Accepted: 07/11/2023] [Indexed: 08/19/2023] Open
Abstract
The human chaperone DNAJB6b increases the solubility of proteins involved in protein aggregation diseases and suppresses the nucleation of amyloid structures. Due to such favourable properties, DNAJB6b has gained increasing attention over the past decade. The understanding of how DNAJB6b operates on a molecular level may aid the design of inhibitors against amyloid formation. In this work, fundamental aspects of DNAJB6b self-assembly have been examined, providing a basis for future experimental designs and conclusions. The results imply the formation of large chaperone clusters in a concentration-dependent manner. Microfluidic diffusional sizing (MDS) was used to evaluate how DNAJB6b average hydrodynamic radius varies with concentration. We found that, in 20 mM sodium phosphate buffer, 0.2 mM EDTA, at pH 8.0 and room temperature, DNAJB6b displays a micellar behaviour, with a critical micelle concentration (CMC) of around 120 nM. The average hydrodynamic radius appears to be concentration independent between ∼10 μM and 100 μM, with a mean radius of about 12 nm. The CMC found by MDS is supported by native agarose gel electrophoresis and the size distribution appears bimodal in the DNAJB6b concentration range ∼100 nM to 4 μM.
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Affiliation(s)
- Andreas Carlsson
- Biochemistry and Structural Biology, Chemical Centre, Lund University, Lund, Sweden
| | - Ulf Olsson
- Physical Chemistry, Chemical Centre, Lund University, Lund, Sweden
| | - Sara Linse
- Biochemistry and Structural Biology, Chemical Centre, Lund University, Lund, Sweden
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23
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Perez VA, Sanders DW, Mendoza-Oliva A, Stopschinski BE, Mullapudi V, White CL, Joachimiak LA, Diamond MI. DnaJC7 specifically regulates tau seeding. eLife 2023; 12:e86936. [PMID: 37387473 PMCID: PMC10473839 DOI: 10.7554/elife.86936] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/29/2023] [Indexed: 07/01/2023] Open
Abstract
Neurodegenerative tauopathies are caused by accumulation of toxic tau protein assemblies. This appears to involve template-based seeding events, whereby tau monomer changes conformation and is recruited to a growing aggregate. Several large families of chaperone proteins, including Hsp70s and J domain proteins (JDPs), cooperate to regulate the folding of intracellular proteins such as tau, but the factors that coordinate this activity are not well known. The JDP DnaJC7 binds tau and reduces its intracellular aggregation. However, it is unknown whether this is specific to DnaJC7 or if other JDPs might be similarly involved. We used proteomics within a cell model to determine that DnaJC7 co-purified with insoluble tau and colocalized with intracellular aggregates. We individually knocked out every possible JDP and tested the effect on intracellular aggregation and seeding. DnaJC7 knockout decreased aggregate clearance and increased intracellular tau seeding. This depended on the ability of the J domain (JD) of DnaJC7 to stimulate Hsp70 ATPase activity, as JD mutations that block this interaction abrogated the protective activity. Disease-associated mutations in the JD and substrate binding site of DnaJC7 also abolished its protective activity. DnaJC7 thus specifically regulates tau aggregation in cooperation with Hsp70.
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Affiliation(s)
- Valerie Ann Perez
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - David W Sanders
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Ayde Mendoza-Oliva
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Barbara Elena Stopschinski
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Vishruth Mullapudi
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Charles L White
- Department of Pathology, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biochemistry, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Neurology, Peter O’Donnell Jr. Brain Institute, The University of Texas Southwestern Medical CenterDallasUnited States
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24
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Sanchez-Rodriguez D, Gonzalez-Figueroa I, Alvarez-Berríos MP. Chaperone Activity and Protective Effect against Aβ-Induced Cytotoxicity of Artocarpus camansi Blanco and Amaranthus dubius Mart. ex Thell Seed Protein Extracts. Pharmaceuticals (Basel) 2023; 16:820. [PMID: 37375767 DOI: 10.3390/ph16060820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Alzheimer's disease (AD) is the most common type of dementia and is listed as the sixth-leading cause of death in the United States. Recent findings have linked AD to the aggregation of amyloid beta peptides (Aβ), a proteolytic fragment of 39-43 amino acid residues derived from the amyloid precursor protein. AD has no cure; thus, new therapies to stop the progression of this deadly disease are constantly being searched for. In recent years, chaperone-based medications from medicinal plants have gained significant interest as an anti-AD therapy. Chaperones are responsible for maintaining the three-dimensional shape of proteins and play an important role against neurotoxicity induced by the aggregation of misfolded proteins. Therefore, we hypothesized that proteins extracted from the seeds of Artocarpus camansi Blanco (A. camansi) and Amaranthus dubius Mart. ex Thell (A. dubius) could possess chaperone activity and consequently may exhibit a protective effect against Aβ1-40-induced cytotoxicity. To test this hypothesis, the chaperone activity of these protein extracts was measured using the enzymatic reaction of citrate synthase (CS) under stress conditions. Then, their ability to inhibit the aggregation of Aβ1-40 using a thioflavin T (ThT) fluorescence assay and DLS measurements was determined. Finally, the neuroprotective effect against Aβ1-40 in SH-SY5Y neuroblastoma cells was evaluated. Our results demonstrated that A. camansi and A. dubius protein extracts exhibited chaperone activity and inhibited Aβ1-40 fibril formation, with A. dubius showing the highest chaperone activity and inhibition at the concentration assessed. Additionally, both protein extracts showed neuroprotective effects against Aβ1-40-induced toxicity. Overall, our data demonstrated that the plant-based proteins studied in this research work can effectively overcome one of the most important characteristics of AD.
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Affiliation(s)
- David Sanchez-Rodriguez
- Department of Science and Technology, Inter American University of Puerto Rico at Ponce, Ponce, PR 00715-1602, USA
| | - Idsa Gonzalez-Figueroa
- Department of Science and Technology, Inter American University of Puerto Rico at Ponce, Ponce, PR 00715-1602, USA
| | - Merlis P Alvarez-Berríos
- Department of Science and Technology, Inter American University of Puerto Rico at Ponce, Ponce, PR 00715-1602, USA
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25
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Abelein A, Johansson J. Amyloid inhibition by molecular chaperones in vitro can be translated to Alzheimer's pathology in vivo. RSC Med Chem 2023; 14:848-857. [PMID: 37252101 PMCID: PMC10211315 DOI: 10.1039/d3md00040k] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/21/2023] [Indexed: 09/23/2023] Open
Abstract
Molecular chaperones are important components in the cellular quality-control machinery and increasing evidence points to potential new roles for them as suppressors of amyloid formation in neurodegenerative diseases, such as Alzheimer's disease. Approaches to treat Alzheimer's disease have not yet resulted in an effective treatment, suggesting that alternative strategies may be useful. Here, we discuss new treatment approaches based on molecular chaperones that inhibit amyloid-β (Aβ) aggregation by different microscopic mechanisms of action. Molecular chaperones that specifically target secondary nucleation reactions during Aβ aggregation in vitro - a process closely associated with Aβ oligomer generation - have shown promising results in animal treatment studies. The inhibition of Aβ oligomer generation in vitro seemingly correlates with the effects of treatment, giving indirect clues about the molecular mechanisms present in vivo. Interestingly, recent immunotherapy advances, which have demonstrated significant improvements in clinical phase III trials, have used antibodies that selectively act against Aβ oligomer formation, supporting the notion that specific inhibition of Aβ neurotoxicity is more rewarding than reducing overall amyloid fibril formation. Hence, specific modulation of chaperone activity represents a promising new strategy for treatment of neurodegenerative disorders.
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Affiliation(s)
- Axel Abelein
- Department of Biosciences and Nutrition, Karolinska Institutet 141 83 Huddinge Sweden
| | - Jan Johansson
- Department of Biosciences and Nutrition, Karolinska Institutet 141 83 Huddinge Sweden
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26
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Ghosh S, Tugarinov V, Clore GM. Quantitative NMR analysis of the mechanism and kinetics of chaperone Hsp104 action on amyloid-β42 aggregation and fibril formation. Proc Natl Acad Sci U S A 2023; 120:e2305823120. [PMID: 37186848 PMCID: PMC10214214 DOI: 10.1073/pnas.2305823120] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 04/19/2023] [Indexed: 05/17/2023] Open
Abstract
The chaperone Hsp104, a member of the Hsp100/Clp family of translocases, prevents fibril formation of a variety of amyloidogenic peptides in a paradoxically substoichiometric manner. To understand the mechanism whereby Hsp104 inhibits fibril formation, we probed the interaction of Hsp104 with the Alzheimer's amyloid-β42 (Aβ42) peptide using a variety of biophysical techniques. Hsp104 is highly effective at suppressing the formation of Thioflavin T (ThT) reactive mature fibrils that are readily observed by atomic force (AFM) and electron (EM) microscopies. Quantitative kinetic analysis and global fitting was performed on serially recorded 1H-15N correlation spectra to monitor the disappearance of Aβ42 monomers during the course of aggregation over a wide range of Hsp104 concentrations. Under the conditions employed (50 μM Aβ42 at 20 °C), Aβ42 aggregation occurs by a branching mechanism: an irreversible on-pathway leading to mature fibrils that entails primary and secondary nucleation and saturating elongation; and a reversible off-pathway to form nonfibrillar oligomers, unreactive to ThT and too large to be observed directly by NMR, but too small to be visualized by AFM or EM. Hsp104 binds reversibly with nanomolar affinity to sparsely populated Aβ42 nuclei present in nanomolar concentrations, generated by primary and secondary nucleation, thereby completely inhibiting on-pathway fibril formation at substoichiometric ratios of Hsp104 to Aβ42 monomers. Tight binding to sparsely populated nuclei likely constitutes a general mechanism for substoichiometric inhibition of fibrillization by a variety of chaperones. Hsp104 also impacts off-pathway oligomerization but to a much smaller degree initially reducing and then increasing the rate of off-pathway oligomerization.
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Affiliation(s)
- Shreya Ghosh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
| | - Vitali Tugarinov
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
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27
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Kumar R, Arroyo-García LE, Manchanda S, Adam L, Pizzirusso G, Biverstål H, Nilsson P, Fisahn A, Johansson J, Abelein A. Molecular Mechanisms of Amyloid-β Self-Assembly Seeded by In Vivo-Derived Fibrils and Inhibitory Effects of the BRICHOS Chaperone. ACS Chem Neurosci 2023; 14. [PMID: 37023330 PMCID: PMC10119923 DOI: 10.1021/acschemneuro.3c00044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
Self-replication of amyloid-β-peptide (Aβ) fibril formation is a hallmark in Alzheimer's disease (AD). Detailed insights have been obtained in Aβ self-assembly in vitro, yet whether similar mechanisms are relevant in vivo has remained elusive. Here, we investigated the ability of in vivo-derived Aβ fibrils from two different amyloid precursor protein knock-in AD mouse models to seed Aβ42 aggregation, where we quantified the microscopic rate constants. We found that the nucleation mechanism of in vivo-derived fibril-seeded Aβ42 aggregation can be described with the same kinetic model as that in vitro. Further, we identified the inhibitory mechanism of the anti-amyloid BRICHOS chaperone on seeded Aβ42 fibrillization, revealing a suppression of secondary nucleation and fibril elongation, which is strikingly similar as observed in vitro. These findings hence provide a molecular understanding of the Aβ42 nucleation process triggered by in vivo-derived Aβ42 propagons, providing a framework for the search for new AD therapeutics.
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Affiliation(s)
- Rakesh Kumar
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
| | - Luis Enrique Arroyo-García
- Division
of Neurogeriatrics; Center for Alzheimer Research; Department of Neurobiology,
Care Sciences and Society, Karolinska Institutet, 171 64 Solna, Sweden
- Department
of Women’s and Children’s Health, Karolinska Institutet, 171 64 Solna, Sweden
| | - Shaffi Manchanda
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
| | - Laurène Adam
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
| | - Giusy Pizzirusso
- Division
of Neurogeriatrics; Center for Alzheimer Research; Department of Neurobiology,
Care Sciences and Society, Karolinska Institutet, 171 64 Solna, Sweden
- Department
of Women’s and Children’s Health, Karolinska Institutet, 171 64 Solna, Sweden
| | - Henrik Biverstål
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
| | - Per Nilsson
- Division
of Neurogeriatrics; Center for Alzheimer Research; Department of Neurobiology,
Care Sciences and Society, Karolinska Institutet, 171 64 Solna, Sweden
| | - André Fisahn
- Division
of Neurogeriatrics; Center for Alzheimer Research; Department of Neurobiology,
Care Sciences and Society, Karolinska Institutet, 171 64 Solna, Sweden
| | - Jan Johansson
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
| | - Axel Abelein
- Department
of Biosciences and Nutrition, Karolinska
Institutet, 141 52 Huddinge, Sweden
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28
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Perez VA, Sanders DW, Mendoza-Oliva A, Stopschinski BE, Mullapudi V, White CL, Joachimiak LA, Diamond MI. DnaJC7 specifically regulates tau seeding. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.532880. [PMID: 36993367 PMCID: PMC10055123 DOI: 10.1101/2023.03.16.532880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Neurodegenerative tauopathies are caused by accumulation of toxic tau protein assemblies. This appears to involve template-based seeding events, whereby tau monomer changes conformation and is recruited to a growing aggregate. Several large families of chaperone proteins, including Hsp70s and J domain proteins (JDPs) cooperate to regulate the folding of intracellular proteins such as tau, but the factors that coordinate this activity are not well known. The JDP DnaJC7 binds tau and reduces its intracellular aggregation. However, it is unknown whether this is specific to DnaJC7 or if other JDPs might be similarly involved. We used proteomics within a cell model to determine that DnaJC7 co-purified with insoluble tau and colocalized with intracellular aggregates. We individually knocked out every possible JDP and tested the effect on intracellular aggregation and seeding. DnaJC7 knockout decreased aggregate clearance and increased intracellular tau seeding. This depended on the ability of the J domain (JD) of DnaJC7 to bind to Hsp70, as JD mutations that block binding to Hsp70 abrogated the protective activity. Disease-associated mutations in the JD and substrate binding site of DnaJC7 also abrogated its protective activity. DnaJC7 thus specifically regulates tau aggregation in cooperation with Hsp70.
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Affiliation(s)
- Valerie A Perez
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - David W Sanders
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ayde Mendoza-Oliva
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Barbara E Stopschinski
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Vishruth Mullapudi
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Charles L White
- Department of Pathology, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
- Department of Biochemistry, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
- Department of Neurology, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX
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29
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Puneeth Kumar DRGKR, Reja RM, Senapati DK, Singh M, Nalawade SA, George G, Kaul G, Akhir A, Chopra S, Raghothama S, Gopi HN. A cationic amphiphilic peptide chaperone rescues Aβ 42 aggregation and cytotoxicity. RSC Med Chem 2023; 14:332-340. [PMID: 36846376 PMCID: PMC9945854 DOI: 10.1039/d2md00414c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
Directing Aβ42 to adopt a conformation that is free from aggregation and cell toxicity is an attractive and viable strategy to design therapeutics for Alzheimer's disease. Over the years, extensive efforts have been made to disrupt the aggregation of Aβ42 using various types of inhibitors but with limited success. Herein, we report the inhibition of aggregation of Aβ42 and disintegration of matured fibrils of Aβ42 into smaller assemblies by a 15-mer cationic amphiphilic peptide. The biophysical analysis comprising thioflavin T (ThT) mediated amyloid aggregation kinetic analysis, dynamic light scattering, ELISA, AFM, and TEM suggested that the peptide effectively disrupts Aβ42 aggregation. The circular dichroism (CD) and 2D-NMR HSQC analysis reveal that upon interaction, the peptide induces a conformational change in Aβ42 that is free from aggregation. Further, the cell assay experiments revealed that this peptide is non-toxic to cells and also rescues the cells from the toxicity of Aβ42. Peptides with a shorter length displayed either weak or no inhibitory effect on Aβ42 aggregation and cytotoxicity. These results suggest that the 15-residue cationic amphiphilic peptide reported here may serve as a potential therapeutic candidate for Alzheimer's disease.
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Affiliation(s)
- DRGKoppalu R. Puneeth Kumar
- Department of Chemistry, Indian Institute of Science Education and ResearchDr. Homi Bhabha Road, PashanPune-411008India
| | - Rahi M. Reja
- Department of Chemistry, Indian Institute of Science Education and ResearchDr. Homi Bhabha Road, PashanPune-411008India
| | | | - Manjeet Singh
- Department of Chemistry, Indian Institute of Science Education and Research Dr. Homi Bhabha Road, Pashan Pune-411008 India
| | - Sachin A. Nalawade
- Department of Chemistry, Indian Institute of Science Education and ResearchDr. Homi Bhabha Road, PashanPune-411008India
| | - Gijo George
- NMR Research Centre, Indian Institute of ScienceBangalore-560012India
| | - Grace Kaul
- Division of Microbiology and Division of Medicinal and Process Chemistry, CSIR-Central Drug Research InstituteSitapur Road, Sector 10, Janakipuram ExtensionLucknow-226031Uttar PradeshIndia,AcSIR: Academy of Scientific and Innovative Research (AcSIR)Ghaziabad 201002India
| | - Abdul Akhir
- Division of Microbiology and Division of Medicinal and Process Chemistry, CSIR-Central Drug Research InstituteSitapur Road, Sector 10, Janakipuram ExtensionLucknow-226031Uttar PradeshIndia
| | - Sidharth Chopra
- Division of Microbiology and Division of Medicinal and Process Chemistry, CSIR-Central Drug Research InstituteSitapur Road, Sector 10, Janakipuram ExtensionLucknow-226031Uttar PradeshIndia,AcSIR: Academy of Scientific and Innovative Research (AcSIR)Ghaziabad 201002India
| | | | - Hosahudya N. Gopi
- Department of Chemistry, Indian Institute of Science Education and ResearchDr. Homi Bhabha Road, PashanPune-411008India
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30
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The chaperone DNAJB6 surveils FG-nucleoporins and is required for interphase nuclear pore complex biogenesis. Nat Cell Biol 2022; 24:1584-1594. [PMID: 36302971 DOI: 10.1038/s41556-022-01010-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 09/12/2022] [Indexed: 01/18/2023]
Abstract
Biogenesis of nuclear pore complexes (NPCs) includes the formation of the permeability barrier composed of phenylalanine-glycine-rich nucleoporins (FG-Nups) that regulate the selective passage of biomolecules across the nuclear envelope. The FG-Nups are intrinsically disordered and prone to liquid-liquid phase separation and aggregation when isolated. How FG-Nups are protected from making inappropriate interactions during NPC biogenesis is not fully understood. Here we find that DNAJB6, a molecular chaperone of the heat shock protein network, forms foci in close proximity to NPCs. The number of these foci decreases upon removal of proteins involved in the early steps of interphase NPC biogenesis. Conversely, when this process is stalled in the last steps, the number of DNAJB6-containing foci increases and these foci are identified as herniations at the nuclear envelope. Immunoelectron tomography shows that DNAJB6 localizes inside the lumen of the herniations arising at NPC biogenesis intermediates. Loss of DNAJB6 results in the accumulation of cytosolic annulate lamellae, which are structures containing partly assembled NPCs, a feature associated with disturbances in NPC biogenesis. We find that DNAJB6 binds to FG-Nups and can prevent the aggregation of the FG region of several FG-Nups in cells and in vitro. Together, our data show that the molecular chaperone DNAJB6 provides quality control during NPC biogenesis and is involved in the surveillance of native intrinsically disordered FG-Nups.
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31
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J Proteins Counteract Amyloid Propagation and Toxicity in Yeast. BIOLOGY 2022; 11:biology11091292. [PMID: 36138771 PMCID: PMC9495310 DOI: 10.3390/biology11091292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022]
Abstract
Simple Summary Dozens of diseases are associated with misfolded proteins that accumulate in highly ordered fibrous aggregates called amyloids. Protein quality control (PQC) factors keep cells healthy by helping maintain the integrity of the cell’s proteins and physiological processes. Yeast has been used widely for years to study how amyloids cause toxicity to cells and how PQC factors help protect cells from amyloid toxicity. The so-called J-domain proteins (JDPs) are PQC factors that are particularly effective at providing such protection. We discuss how PQC factors protect animals, human cells, and yeast from amyloid toxicity, focusing on yeast and human JDPs. Abstract The accumulation of misfolded proteins as amyloids is associated with pathology in dozens of debilitating human disorders, including diabetes, Alzheimer’s, Parkinson’s, and Huntington’s diseases. Expressing human amyloid-forming proteins in yeast is toxic, and yeast prions that propagate as infectious amyloid forms of cellular proteins are also harmful. The yeast system, which has been useful for studying amyloids and their toxic effects, has provided much insight into how amyloids affect cells and how cells respond to them. Given that an amyloid is a protein folding problem, it is unsurprising that the factors found to counteract the propagation or toxicity of amyloids in yeast involve protein quality control. Here, we discuss such factors with an emphasis on J-domain proteins (JDPs), which are the most highly abundant and diverse regulators of Hsp70 chaperones. The anti-amyloid effects of JDPs can be direct or require interaction with Hsp70.
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32
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Zhong X, Kumar R, Wang Y, Biverstål H, Ingeborg Jegerschöld C, J B Koeck P, Johansson J, Abelein A, Chen G. Amyloid Fibril Formation of Arctic Amyloid-β 1-42 Peptide is Efficiently Inhibited by the BRICHOS Domain. ACS Chem Biol 2022; 17:2201-2211. [PMID: 35876740 PMCID: PMC9396614 DOI: 10.1021/acschembio.2c00344] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloid-β peptide (Aβ) aggregation is one of the hallmarks of Alzheimer's disease (AD). Mutations in Aβ are associated with early onset familial AD, and the Arctic mutant E22G (Aβarc) is an extremely aggregation-prone variant. Here, we show that BRICHOS, a natural anti-amyloid chaperone domain, from Bri2 efficiently inhibits aggregation of Aβarc by mainly interfering with secondary nucleation. This is qualitatively different from the microscopic inhibition mechanism for the wild-type Aβ, against which Bri2 BRICHOS has a major effect on both secondary nucleation and fibril end elongation. The monomeric Aβ42arc peptide aggregates into amyloid fibrils significantly faster than wild-type Aβ (Aβ42wt), as monitored by thioflavin T (ThT) binding, but the final ThT intensity was strikingly lower for Aβ42arc compared to Aβ42wt fibrils. The Aβ42arc peptide formed large aggregates, single-filament fibrils, and multiple-filament fibrils without obvious twists, while Aβ42wt fibrils displayed a polymorphic pattern with typical twisted fibril architecture. Recombinant human Bri2 BRICHOS binds to the Aβ42arc fibril surface and interferes with the macroscopic fibril arrangement by promoting single-filament fibril formation. This study provides mechanistic insights on how BRICHOS efficiently affects the aggressive Aβ42arc aggregation, resulting in both delayed fibril formation kinetics and altered fibril structure.
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Affiliation(s)
- Xueying Zhong
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, 141 52 Huddinge, Sweden
| | - Rakesh Kumar
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Yu Wang
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden.,College of Wildlife and Protected Area, Northeast Forestry University, 150040 Harbin, People's Republic of China
| | - Henrik Biverstål
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Caroline Ingeborg Jegerschöld
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, 141 52 Huddinge, Sweden
| | - Philip J B Koeck
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, 141 52 Huddinge, Sweden
| | - Jan Johansson
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Axel Abelein
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Gefei Chen
- The Department of Biosciences and Nutrition, Karolinska Institutet, 141 52 Huddinge, Sweden
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33
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Johnson OT, Gestwicki JE. Multivalent protein-protein interactions are pivotal regulators of eukaryotic Hsp70 complexes. Cell Stress Chaperones 2022; 27:397-415. [PMID: 35670950 PMCID: PMC9346034 DOI: 10.1007/s12192-022-01281-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
Heat shock protein 70 (Hsp70) is a molecular chaperone and central regulator of protein homeostasis (proteostasis). Paramount to this role is Hsp70's binding to client proteins and co-chaperones to produce distinct complexes, such that understanding the protein-protein interactions (PPIs) of Hsp70 is foundational to describing its function and dysfunction in disease. Mounting evidence suggests that these PPIs include both "canonical" interactions, which are universally conserved, and "non-canonical" (or "secondary") contacts that seem to have emerged in eukaryotes. These two categories of interactions involve discrete binding surfaces, such that some clients and co-chaperones engage Hsp70 with at least two points of contact. While the contributions of canonical interactions to chaperone function are becoming increasingly clear, it can be challenging to deconvolute the roles of secondary interactions. Here, we review what is known about non-canonical contacts and highlight examples where their contributions have been parsed, giving rise to a model in which Hsp70's secondary contacts are not simply sites of additional avidity but are necessary and sufficient to impart unique functions. From this perspective, we propose that further exploration of non-canonical contacts will generate important insights into the evolution of Hsp70 systems and inspire new approaches for developing small molecules that tune Hsp70-mediated proteostasis.
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Affiliation(s)
- Oleta T Johnson
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, 94158, USA.
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34
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Ji G, Wang N, Han X, Wang Y, Zhang J, Wu Y, Wu H, Ma S, Song X. Case Report: A Novel Splice-Site Mutation in DNAJB6 Associated With Juvenile-Onset Proximal–Distal Myopathy in a Chinese Patient. Front Genet 2022; 13:925926. [PMID: 35812750 PMCID: PMC9259785 DOI: 10.3389/fgene.2022.925926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/13/2022] [Indexed: 11/29/2022] Open
Abstract
DNAJB6 was identified as the causative gene of limb-girdle muscular dystrophy type 1D. In recent years, the phenotypic and molecular spectrum of DNAJB6-myopathy has been expanded, and several mutations of DNAJB6 have been identified in Europe, North America, and Asia. Interestingly, almost all identified mutations in previous reports were point mutations, and most of them were clustered in exon 5, which encodes the G/F domain of DNAJB6. The so-far unique splice site mutation eliminating the entire G/F domain was reported to cause a severe, early-onset phenotype. Here, we report a juvenile-onset Chinese patient who presented with proximal–distal myopathy as well as esotropia and facial weakness. Muscle pathology showed rimmed vacuolation and myofibrillar disarrangement. A novel splice-site mutation NM_058246:c.236-1_240delGGTGGA of the DNAJB6 gene was identified by targeted exome sequencing, which results in a severe defect of the G/F domain. This rare mutation type expands the molecular spectrum of DNAJB6-myopathy and further underlines the importance of the G/F region.
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Affiliation(s)
- Guang Ji
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Ning Wang
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Xu Han
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Yaye Wang
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Jinru Zhang
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Yue Wu
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Hongran Wu
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Shaojuan Ma
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Xueqin Song
- Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Neurological Laboratory of Hebei Province, Shijiazhuang, China
- *Correspondence: Xueqin Song,
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35
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Benhamou Goldfajn N, Tang H, Ding F. Substoichiometric Inhibition of Insulin against IAPP Aggregation Is Attenuated by the Incompletely Processed N-Terminus of proIAPP. ACS Chem Neurosci 2022; 13:2006-2016. [PMID: 35704461 DOI: 10.1021/acschemneuro.2c00231] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Substoichiometric aggregation inhibition of human islet amyloid polypeptide (IAPP), the hallmark of type 2 diabetes impacting millions of people, is crucial for developing clinic therapies, yet it remains challenging given that many candidate inhibitors require high doses. Intriguingly, insulin, the key regulatory polypeptide on blood glucose levels that are cosynthesized, costored, and cosecreted with IAPP by pancreatic β cells, has been identified as a potent inhibitor that can suppress IAPP amyloid aggregation at substoichiometric concentrations. Here, we computationally investigated the molecular mechanisms of the substoichiometric inhibition of insulin against the aggregation of IAPP and the incompletely processed IAPP (proIAPP) using discrete molecular dynamics simulations. Our results suggest that the amyloid aggregations of both IAPP and proIAPP might be disrupted by insulin through its binding with the shared amyloidogenic core sequences. However, the N-terminus of proIAPP competed with the amyloidogenic core sequences for the insulin interactions, resulting in attenuated inhibition by insulin. Moreover, insulin preferred to bind the elongation surfaces of IAPP seeds with fibril-like structure, with a stronger affinity than that of IAPP monomers. The capping of elongation surfaces by a small amount of insulin sterically prohibited the seed growth via monomer addition, achieving the substoichiometric inhibition. Together, our computational results provided molecular insights for the substoichiometric inhibition of insulin against IAPP aggregation, also the weakened effect on proIAPP. The uncovered substoichiometric inhibition by capping the elongation of amyloid seeds or fibrils may guide the rational designs of new potent inhibitors effective at low doses.
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Affiliation(s)
- Nadav Benhamou Goldfajn
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States.,University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Huayuan Tang
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
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36
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Linse S, Sormanni P, O’Connell DJ. An aggregation inhibitor specific to oligomeric intermediates of Aβ42 derived from phage display libraries of stable, small proteins. Proc Natl Acad Sci U S A 2022; 119:e2121966119. [PMID: 35580187 PMCID: PMC9173773 DOI: 10.1073/pnas.2121966119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 04/07/2022] [Indexed: 01/04/2023] Open
Abstract
The self-assembly of amyloid β peptide (Aβ) to fibrillar and oligomeric aggregates is linked to Alzheimer’s disease. Aβ binders may serve as inhibitors of aggregation to prevent the generation of neurotoxic species and for the detection of Aβ species. A particular challenge involves finding binders to on-pathway oligomers given their transient nature. Here we construct two phage–display libraries built on the highly inert and stable protein scaffold S100G, one containing a six-residue variable surface patch and one harboring a seven-residue variable loop insertion. Monomers and fibrils of Aβ40 and Aβ42 were separately coupled to silica nanoparticles, using a coupling strategy leading to the presence of oligomers on the monomer beads, and they were used in three rounds of affinity selection. Next-generation sequencing revealed sequence clusters and candidate binding proteins (SXkmers). Two SXkmers were expressed as soluble proteins and tested in terms of aggregation inhibition via thioflavin T fluorescence. We identified an SXkmer with loop–insertion YLTIRLM as an inhibitor of the secondary nucleation of Aβ42 and binding analyses using surface plasmon resonance technology, Förster resonance energy transfer, and microfluidics diffusional sizing imply an interaction with intermediate oligomeric species. A linear peptide with the YLTIRLM sequence was found inhibitory but at a lower potency than the more constrained SXkmer loop. We identified an SXkmer with side-patch VI-WI-DD as an inhibitor of Aβ40 aggregation. Remarkably, our data imply that SXkmer-YLTIRLM blocks secondary nucleation through an interaction with oligomeric intermediates in solution or at the fibril surface, which is a unique inhibitory mechanism for a library-derived inhibitor.
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Affiliation(s)
- Sara Linse
- Biochemistry and Structural Biology, Lund University, SE-22100 Lund, Sweden
| | - Pietro Sormanni
- Chemistry of Health, Yusuf Hamied Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK
| | - David J. O’Connell
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin D04 V1W8, Ireland
- BiOrbic, Bioeconomy SFI Research Centre, University College Dublin, Dublin 04 V1W8, Ireland
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37
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Calabrese G, Molzahn C, Mayor T. Protein interaction networks in neurodegenerative diseases: from physiological function to aggregation. J Biol Chem 2022; 298:102062. [PMID: 35623389 PMCID: PMC9234719 DOI: 10.1016/j.jbc.2022.102062] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/26/2022] [Accepted: 05/18/2022] [Indexed: 11/25/2022] Open
Abstract
The accumulation of protein inclusions is linked to many neurodegenerative diseases that typically develop in older individuals, due to a combination of genetic and environmental factors. In rare familial neurodegenerative disorders, genes encoding for aggregation-prone proteins are often mutated. While the underlying mechanism leading to these diseases still remains to be fully elucidated, efforts in the past 20 years revealed a vast network of protein–protein interactions that play a major role in regulating the aggregation of key proteins associated with neurodegeneration. Misfolded proteins that can oligomerize and form insoluble aggregates associate with molecular chaperones and other elements of the proteolytic machineries that are the frontline workers attempting to protect the cells by promoting clearance and preventing aggregation. Proteins that are normally bound to aggregation-prone proteins can become sequestered and mislocalized in protein inclusions, leading to their loss of function. In contrast, mutations, posttranslational modifications, or misfolding of aggregation-prone proteins can lead to gain of function by inducing novel or altered protein interactions, which in turn can impact numerous essential cellular processes and organelles, such as vesicle trafficking and the mitochondria. This review examines our current knowledge of protein–protein interactions involving several key aggregation-prone proteins that are associated with Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, or amyotrophic lateral sclerosis. We aim to provide an overview of the protein interaction networks that play a central role in driving or mitigating inclusion formation, while highlighting some of the key proteomic studies that helped to uncover the extent of these networks.
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Affiliation(s)
- Gaetano Calabrese
- Michael Smith Laboratories, University of British Columbia, V6T 1Z4 Vancouver BC, Canada.
| | - Cristen Molzahn
- Michael Smith Laboratories, University of British Columbia, V6T 1Z4 Vancouver BC, Canada
| | - Thibault Mayor
- Michael Smith Laboratories, University of British Columbia, V6T 1Z4 Vancouver BC, Canada.
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38
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Ring J, Tadic J, Ristic S, Poglitsch M, Bergmann M, Radic N, Mossmann D, Liang Y, Maglione M, Jerkovic A, Hajiraissi R, Hanke M, Küttner V, Wolinski H, Zimmermann A, Domuz Trifunović L, Mikolasch L, Moretti DN, Broeskamp F, Westermayer J, Abraham C, Schauer S, Dammbrueck C, Hofer SJ, Abdellatif M, Grundmeier G, Kroemer G, Braun RJ, Hansen N, Sommer C, Ninkovic M, Seba S, Rockenfeller P, Vögtle F, Dengjel J, Meisinger C, Keller A, Sigrist SJ, Eisenberg T, Madeo F. The HSP40 chaperone Ydj1 drives amyloid beta 42 toxicity. EMBO Mol Med 2022; 14:e13952. [PMID: 35373908 PMCID: PMC9081910 DOI: 10.15252/emmm.202113952] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/12/2022] [Accepted: 02/15/2022] [Indexed: 01/22/2023] Open
Abstract
Amyloid beta 42 (Abeta42) is the principal trigger of neurodegeneration during Alzheimer's disease (AD). However, the etiology of its noxious cellular effects remains elusive. In a combinatory genetic and proteomic approach using a yeast model to study aspects of intracellular Abeta42 toxicity, we here identify the HSP40 family member Ydj1, the yeast orthologue of human DnaJA1, as a crucial factor in Abeta42-mediated cell death. We demonstrate that Ydj1/DnaJA1 physically interacts with Abeta42 (in yeast and mouse), stabilizes Abeta42 oligomers, and mediates their translocation to mitochondria. Consequently, deletion of YDJ1 strongly reduces co-purification of Abeta42 with mitochondria and prevents Abeta42-induced mitochondria-dependent cell death. Consistently, purified DnaJ chaperone delays Abeta42 fibrillization in vitro, and heterologous expression of human DnaJA1 induces formation of Abeta42 oligomers and their deleterious translocation to mitochondria in vivo. Finally, downregulation of the Ydj1 fly homologue, Droj2, improves stress resistance, mitochondrial morphology, and memory performance in a Drosophila melanogaster AD model. These data reveal an unexpected and detrimental role for specific HSP40s in promoting hallmarks of Abeta42 toxicity.
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39
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Cawood EE, Clore GM, Karamanos TK. Microsecond Backbone Motions Modulate the Oligomerization of the DNAJB6 Chaperone. Angew Chem Int Ed Engl 2022; 61:e202116403. [PMID: 35247211 PMCID: PMC9314120 DOI: 10.1002/anie.202116403] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Indexed: 11/12/2022]
Abstract
DNAJB6 is a prime example of an anti-aggregation chaperone that functions as an oligomer. DNAJB6 oligomers are dynamic and subunit exchange is critical for inhibiting client protein aggregation. The T193A mutation in the C-terminal domain (CTD) of DNAJB6 reduces both chaperone self-oligomerization and anti-aggregation of client proteins, and has recently been linked to Parkinson's disease. Here, we show by NMR, including relaxation-based methods, that the T193A mutation has minimal effects on the structure of the β-stranded CTD but increases the population and rate of formation of a partially folded state. The results can be rationalized in terms of β-strand peptide plane flips that occur on a timescale of ≈100 μs and lead to global changes in the overall pleat/flatness of the CTD, thereby altering its ability to oligomerize. These findings help forge a link between chaperone dynamics, oligomerization and anti-aggregation activity which may possibly lead to new therapeutic avenues tuned to target specific substrates.
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Affiliation(s)
- Emma E. Cawood
- Astbury Centre for Structural Molecular BiologySchool of Molecular and Cellular BiologyUniversity of LeedsMount Preston StreetLeedsLS2 9JTUK
| | - G. Marius Clore
- Laboratory of Chemical PhysicsNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMD 20892-0520USA
| | - Theodoros K. Karamanos
- Astbury Centre for Structural Molecular BiologySchool of Molecular and Cellular BiologyUniversity of LeedsMount Preston StreetLeedsLS2 9JTUK
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40
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Cawood EE, Clore GM, Karamanos TK. Microsecond Backbone Motions Modulate the Oligomerization of the DNAJB6 Chaperone. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202116403. [PMID: 38505697 PMCID: PMC10947091 DOI: 10.1002/ange.202116403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Indexed: 11/09/2022]
Abstract
DNAJB6 is a prime example of an anti-aggregation chaperone that functions as an oligomer. DNAJB6 oligomers are dynamic and subunit exchange is critical for inhibiting client protein aggregation. The T193A mutation in the C-terminal domain (CTD) of DNAJB6 reduces both chaperone self-oligomerization and anti-aggregation of client proteins, and has recently been linked to Parkinson's disease. Here, we show by NMR, including relaxation-based methods, that the T193A mutation has minimal effects on the structure of the β-stranded CTD but increases the population and rate of formation of a partially folded state. The results can be rationalized in terms of β-strand peptide plane flips that occur on a timescale of ≈100 μs and lead to global changes in the overall pleat/flatness of the CTD, thereby altering its ability to oligomerize. These findings help forge a link between chaperone dynamics, oligomerization and anti-aggregation activity which may possibly lead to new therapeutic avenues tuned to target specific substrates.
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Affiliation(s)
- Emma E. Cawood
- Astbury Centre for Structural Molecular BiologySchool of Molecular and Cellular BiologyUniversity of LeedsMount Preston StreetLeedsLS2 9JTUK
| | - G. Marius Clore
- Laboratory of Chemical PhysicsNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMD 20892-0520USA
| | - Theodoros K. Karamanos
- Astbury Centre for Structural Molecular BiologySchool of Molecular and Cellular BiologyUniversity of LeedsMount Preston StreetLeedsLS2 9JTUK
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41
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Wan Q, Mouton SN, Veenhoff LM, Boersma AJ. A FRET-based method for monitoring structural transitions in protein self-organization. CELL REPORTS METHODS 2022; 2:100184. [PMID: 35475219 PMCID: PMC8960284 DOI: 10.1016/j.crmeth.2022.100184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/12/2021] [Accepted: 02/24/2022] [Indexed: 11/04/2022]
Abstract
Proteins assemble into a variety of dynamic and functional structures. Their structural transitions are often challenging to distinguish inside cells, particularly with a high spatiotemporal resolution. Here, we present a fluorescence resonance energy transfer (FRET)-based method for continuous and high-throughput monitoring of protein self-assemblies to reveal well-resolved transient intermediate states. Intermolecular FRET with both the donor and acceptor proteins at the same target protein provides high sensitivity while retaining the advantage of straightforward ratiometric imaging. We apply this method to monitor self-assembly of three proteins. We show that the mutant Huntingtin exon1 (mHttex1) first forms less-ordered assemblies, which develop into fibril-like aggregates, and demonstrate that the chaperone protein DNAJB6b increases the critical saturation concentration of mHttex1. We also monitor the structural changes in fused in sarcoma (FUS) condensates. This method adds to the toolbox for protein self-assembly structure and kinetics determination, and implementation with native or non-native proteins can inform studies involving protein condensation or aggregation.
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Affiliation(s)
- Qi Wan
- DWI – Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Sara N. Mouton
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Liesbeth M. Veenhoff
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Arnold J. Boersma
- DWI – Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany
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42
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Soluble TREM2 inhibits secondary nucleation of Aβ fibrillization and enhances cellular uptake of fibrillar Aβ. Proc Natl Acad Sci U S A 2022; 119:2114486119. [PMID: 35082148 PMCID: PMC8812518 DOI: 10.1073/pnas.2114486119] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 01/21/2023] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a single-pass transmembrane receptor of the immunoglobulin superfamily that is secreted in a soluble (sTREM2) form. Mutations in TREM2 have been linked to increased risk of Alzheimer's disease (AD). A prominent neuropathological component of AD is deposition of the amyloid-β (Aβ) into plaques, particularly Aβ40 and Aβ42. While the membrane-bound form of TREM2 is known to facilitate uptake of Aβ fibrils and the polarization of microglial processes toward amyloid plaques, the role of its soluble ectodomain, particularly in interactions with monomeric or fibrillar Aβ, has been less clear. Our results demonstrate that sTREM2 does not bind to monomeric Aβ40 and Aβ42, even at a high micromolar concentration, while it does bind to fibrillar Aβ42 and Aβ40 with equal affinities (2.6 ± 0.3 µM and 2.3 ± 0.4 µM). Kinetic analysis shows that sTREM2 inhibits the secondary nucleation step in the fibrillization of Aβ, while having little effect on the primary nucleation pathway. Furthermore, binding of sTREM2 to fibrils markedly enhanced uptake of fibrils into human microglial and neuroglioma derived cell lines. The disease-associated sTREM2 mutant, R47H, displayed little to no effect on fibril nucleation and binding, but it decreased uptake and functional responses markedly. We also probed the structure of the WT sTREM2-Aβ fibril complex using integrative molecular modeling based primarily on the cross-linking mass spectrometry data. The model shows that sTREM2 binds fibrils along one face of the structure, leaving a second, mutation-sensitive site free to mediate cellular binding and uptake.
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43
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Karamanos TK, Clore GM. Large Chaperone Complexes Through the Lens of Nuclear Magnetic Resonance Spectroscopy. Annu Rev Biophys 2022; 51:223-246. [PMID: 35044800 DOI: 10.1146/annurev-biophys-090921-120150] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Molecular chaperones are the guardians of the proteome inside the cell. Chaperones recognize and bind unfolded or misfolded substrates, thereby preventing further aggregation; promoting correct protein folding; and, in some instances, even disaggregating already formed aggregates. Chaperones perform their function by means of an array of weak protein-protein interactions that take place over a wide range of timescales and are therefore invisible to structural techniques dependent upon the availability of highly homogeneous samples. Nuclear magnetic resonance (NMR) spectroscopy, however, is ideally suited to study dynamic, rapidly interconverting conformational states and protein-protein interactions in solution, even if these involve a high-molecular-weight component. In this review, we give a brief overview of the principles used by chaperones to bind their client proteins and describe NMR methods that have emerged as valuable tools to probe chaperone-substrate and chaperone-chaperone interactions. We then focus on a few systems for which the application of these methods has greatly increased our understanding of the mechanisms underlying chaperone functions. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Theodoros K Karamanos
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom;
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA;
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44
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Zhou X, Fennema Galparsoro D, Østergaard Madsen A, Vetri V, van de Weert M, Mørck Nielsen H, Foderà V. Polysorbate 80 controls Morphology, structure and stability of human insulin Amyloid-Like spherulites. J Colloid Interface Sci 2022; 606:1928-1939. [PMID: 34695760 DOI: 10.1016/j.jcis.2021.09.132] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/09/2021] [Accepted: 09/21/2021] [Indexed: 01/09/2023]
Abstract
Amyloid protein aggregates are not only associated with neurodegenerative diseases and may also occur as unwanted by-products in protein-based therapeutics. Surfactants are often employed to stabilize protein formulations and reduce the risk of aggregation. However, surfactants alter protein-protein interactions and may thus modulate the physicochemical characteristics of any aggregates formed. Human insulin aggregation was induced at low pH in the presence of varying concentrations of the surfactant polysorbate 80. Various spectroscopic and imaging methods were used to study the aggregation kinetics, as well as structure and morphology of the formed aggregates. Molecular dynamics simulations were employed to investigate the initial interaction between the surfactant and insulin. Addition of polysorbate 80 slowed down, but did not prevent, aggregation of insulin. Amyloid spherulites formed under all conditions, with a higher content of intermolecular beta-sheets in the presence of the surfactant above its critical micelle concentration. In addition, a denser packing was observed, leading to a more stable aggregate. Molecular dynamics simulations suggested a tendency for insulin to form dimers in the presence of the surfactant, indicating a change in protein-protein interactions. It is thus shown that surfactants not only alter aggregation kinetics, but also affect physicochemical properties of any aggregates formed.
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Affiliation(s)
- Xin Zhou
- Drug Delivery and Biophysics of Biopharmaceuticals, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Dirk Fennema Galparsoro
- Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Ed. 18, Palermo 90128, Italy
| | - Anders Østergaard Madsen
- Manufacturing and Materials, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Valeria Vetri
- Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Ed. 18, Palermo 90128, Italy.
| | - Marco van de Weert
- Drug Delivery and Biophysics of Biopharmaceuticals, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Hanne Mørck Nielsen
- Drug Delivery and Biophysics of Biopharmaceuticals, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Vito Foderà
- Drug Delivery and Biophysics of Biopharmaceuticals, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark.
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45
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Linse S. High-Efficiency Expression and Purification of DNAJB6b Based on the pH-Modulation of Solubility and Denaturant-Modulation of Size. Molecules 2022; 27:418. [PMID: 35056736 PMCID: PMC8781954 DOI: 10.3390/molecules27020418] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/31/2021] [Accepted: 01/02/2022] [Indexed: 02/05/2023] Open
Abstract
The chaperone DNAJB6b delays amyloid formation by suppressing the nucleation of amyloid fibrils and increases the solubility of amyloid-prone proteins. These dual effects on kinetics and equilibrium are related to the unusually high chemical potential of DNAJB6b in solution. As a consequence, the chaperone alone forms highly polydisperse oligomers, whereas in a mixture with an amyloid-forming protein or peptide it may form co-aggregates to gain a reduced chemical potential, thus enabling the amyloid peptide to increase its chemical potential leading to enhanced solubility of the peptide. Understanding such action at the level of molecular driving forces and detailed structures requires access to highly pure and sequence homogeneous DNAJB6b with no sequence extension. We therefore outline here an expression and purification protocol of the protein "as is" with no tags leading to very high levels of pure protein based on its physicochemical properties, including size and charge. The versatility of the protocol is demonstrated through the expression of an isotope labelled protein and seven variants, and the purification of three of these. The activity of the protein is bench-marked using aggregation assays. Two of the variants are used to produce a palette of fluorescent DNAJB6b labelled at an engineered N- or C-terminal cysteine.
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Affiliation(s)
- Sara Linse
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 124, 221 00 Lund, Sweden
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Nagaraj M, Najarzadeh Z, Pansieri J, Biverstål H, Musteikyte G, Smirnovas V, Matthews S, Emanuelsson C, Johansson J, Buxbaum JN, Morozova-Roche L, Otzen DE. Chaperones mainly suppress primary nucleation during formation of functional amyloid required for bacterial biofilm formation. Chem Sci 2022; 13:536-553. [PMID: 35126986 PMCID: PMC8729806 DOI: 10.1039/d1sc05790a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/11/2021] [Indexed: 11/21/2022] Open
Abstract
Unlike misfolding in neurodegenerative diseases, aggregation of functional amyloids involved in bacterial biofilm, e.g. CsgA (E. coli) and FapC (Pseudomonas), is carefully regulated.
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Affiliation(s)
- Madhu Nagaraj
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK – 8000 Aarhus C, Denmark
| | - Zahra Najarzadeh
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK – 8000 Aarhus C, Denmark
| | - Jonathan Pansieri
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
| | - Henrik Biverstål
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, S – 141 83 Huddinge, Sweden
| | - Greta Musteikyte
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Vytautas Smirnovas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Steve Matthews
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW72AZ, UK
| | - Cecilia Emanuelsson
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, PO Box 124, SE-22100 Lund, Sweden
| | - Janne Johansson
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, S – 141 83 Huddinge, Sweden
| | - Joel N. Buxbaum
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | - Daniel E. Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK – 8000 Aarhus C, Denmark
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Joshi BS, Youssef SA, Bron R, de Bruin A, Kampinga HH, Zuhorn IS. DNAJB6b-enriched small extracellular vesicles decrease polyglutamine aggregation in in vitro and in vivo models of Huntington disease. iScience 2021; 24:103282. [PMID: 34755099 PMCID: PMC8564107 DOI: 10.1016/j.isci.2021.103282] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/12/2021] [Accepted: 10/13/2021] [Indexed: 12/19/2022] Open
Abstract
Huntington disease (HD) is a devastating neurodegenerative disorder characterized by aggregation of huntingtin (HTT) protein containing expanded polyglutamine (polyQ) tracts. DNAJB6, a member of the DNAJ chaperone family, was reported to efficiently inhibit polyQ aggregation in vitro, in cell models, and in vivo in flies, xenopus, and mice. For the delivery of exogenous DNAJB6 to the brain, the DNAJB6 needs to be protected against (enzymatic) degradation and show good penetration into brain tissue. Here, we tested the potential of small extracellular vesicles (sEVs) derived from neural stem cells (NSCs) for delivery of DNAJB6 as anti-amyloidogenic cargo. Administration of sEVs isolated from DNAJB6-overexpressing cells to cells expressing expanded polyQ tracts suppressed HTT aggregation. Furthermore, intrathecal injection of DNAJB6-enriched sEVs into R6/2 transgenic HD mice significantly reduced mutant HTT aggregation in the brain. Taken together, our data suggest that sEV-mediated molecular chaperone delivery may hold potential to delay disease onset in HD.
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Affiliation(s)
- Bhagyashree S. Joshi
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV Groningen, the Netherlands
| | - Sameh A. Youssef
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
- Department of Molecular Genetics, Department of Pediatrics, University Medical Center Groningen, Groningen, the Netherlands
| | - Reinier Bron
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV Groningen, the Netherlands
| | - Alain de Bruin
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
- Department of Molecular Genetics, Department of Pediatrics, University Medical Center Groningen, Groningen, the Netherlands
| | - Harm H. Kampinga
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Inge S. Zuhorn
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV Groningen, the Netherlands
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Tikader B, Maji SK, Kar S. A generic approach to decipher the mechanistic pathway of heterogeneous protein aggregation kinetics. Chem Sci 2021; 12:13530-13545. [PMID: 34777773 PMCID: PMC8528017 DOI: 10.1039/d1sc03190b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/01/2021] [Indexed: 12/31/2022] Open
Abstract
Amyloid formation is a generic property of many protein/polypeptide chains. A broad spectrum of proteins, despite having diversity in the inherent precursor sequence and heterogeneity present in the mechanism of aggregation produces a common cross β-spine structure that is often associated with several human diseases. However, a general modeling framework to interpret amyloid formation remains elusive. Herein, we propose a data-driven mathematical modeling approach that elucidates the most probable interaction network for the aggregation of a group of proteins (α-synuclein, Aβ42, Myb, and TTR proteins) by considering an ensemble set of network models, which include most of the mechanistic complexities and heterogeneities related to amyloidogenesis. The best-fitting model efficiently quantifies various timescales involved in the process of amyloidogenesis and explains the mechanistic basis of the monomer concentration dependency of amyloid-forming kinetics. Moreover, the present model reconciles several mutant studies and inhibitor experiments for the respective proteins, making experimentally feasible non-intuitive predictions, and provides further insights about how to fine-tune the various microscopic events related to amyloid formation kinetics. This might have an application to formulate better therapeutic measures in the future to counter unwanted amyloidogenesis. Importantly, the theoretical method used here is quite general and can be extended for any amyloid-forming protein.
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Affiliation(s)
| | - Samir K Maji
- Department of Biosciences and Bioengineering, IIT Bombay Powai Mumbai - 400076 India
| | - Sandip Kar
- Department of Chemistry, IIT Bombay Powai Mumbai - 400076 India
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Jennings MJ, Hathazi D, Nguyen CDL, Munro B, Münchberg U, Ahrends R, Schenck A, Eidhof I, Freier E, Synofzik M, Horvath R, Roos A. Intracellular Lipid Accumulation and Mitochondrial Dysfunction Accompanies Endoplasmic Reticulum Stress Caused by Loss of the Co-chaperone DNAJC3. Front Cell Dev Biol 2021; 9:710247. [PMID: 34692675 PMCID: PMC8526738 DOI: 10.3389/fcell.2021.710247] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 09/02/2021] [Indexed: 12/25/2022] Open
Abstract
Recessive mutations in DNAJC3, an endoplasmic reticulum (ER)-resident BiP co-chaperone, have been identified in patients with multisystemic neurodegeneration and diabetes mellitus. To further unravel these pathomechanisms, we employed a non-biased proteomic approach and identified dysregulation of several key cellular pathways, suggesting a pathophysiological interplay of perturbed lipid metabolism, mitochondrial bioenergetics, ER-Golgi function, and amyloid-beta processing. Further functional investigations in fibroblasts of patients with DNAJC3 mutations detected cellular accumulation of lipids and an increased sensitivity to cholesterol stress, which led to activation of the unfolded protein response (UPR), alterations of the ER-Golgi machinery, and a defect of amyloid precursor protein. In line with the results of previous studies, we describe here alterations in mitochondrial morphology and function, as a major contributor to the DNAJC3 pathophysiology. Hence, we propose that the loss of DNAJC3 affects lipid/cholesterol homeostasis, leading to UPR activation, β-amyloid accumulation, and impairment of mitochondrial oxidative phosphorylation.
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Affiliation(s)
- Matthew J. Jennings
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Denisa Hathazi
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Chi D. L. Nguyen
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Benjamin Munro
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ute Münchberg
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Robert Ahrends
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ilse Eidhof
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Erik Freier
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Centre for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Rita Horvath
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children’s Hospital University of Essen, Essen, Germany
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50
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The binding of the small heat-shock protein αB-crystallin to fibrils of α-synuclein is driven by entropic forces. Proc Natl Acad Sci U S A 2021; 118:2108790118. [PMID: 34518228 PMCID: PMC8463877 DOI: 10.1073/pnas.2108790118] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 11/18/2022] Open
Abstract
Molecular chaperones are key components of the cellular proteostasis network whose role includes the suppression of the formation and proliferation of pathogenic aggregates associated with neurodegenerative diseases. The molecular principles that allow chaperones to recognize misfolded and aggregated proteins remain, however, incompletely understood. To address this challenge, here we probe the thermodynamics and kinetics of the interactions between chaperones and protein aggregates under native solution conditions using a microfluidic platform. We focus on the binding between amyloid fibrils of α-synuclein, associated with Parkinson's disease, to the small heat-shock protein αB-crystallin, a chaperone widely involved in the cellular stress response. We find that αB-crystallin binds to α-synuclein fibrils with high nanomolar affinity and that the binding is driven by entropy rather than enthalpy. Measurements of the change in heat capacity indicate significant entropic gain originates from the disassembly of the oligomeric chaperones that function as an entropic buffer system. These results shed light on the functional roles of chaperone oligomerization and show that chaperones are stored as inactive complexes which are capable of releasing active subunits to target aberrant misfolded species.
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