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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [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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2
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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: 4.0] [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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3
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Atypical nuclear envelope condensates linked to neurological disorders reveal nucleoporin-directed chaperone activities. Nat Cell Biol 2022; 24:1630-1641. [PMID: 36302970 PMCID: PMC10041656 DOI: 10.1038/s41556-022-01001-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 08/26/2022] [Indexed: 01/18/2023]
Abstract
DYT1 dystonia is a debilitating neurological movement disorder arising from mutation in the AAA+ ATPase TorsinA. The hallmark of Torsin dysfunction is nuclear envelope blebbing resulting from defects in nuclear pore complex biogenesis. Whether blebs actively contribute to disease manifestation is unknown. We report that FG-nucleoporins in the bleb lumen form aberrant condensates and contribute to DYT1 dystonia by provoking two proteotoxic insults. Short-lived ubiquitylated proteins that are normally rapidly degraded partition into the bleb lumen and become stabilized. In addition, blebs selectively sequester a specific HSP40-HSP70 chaperone network that is modulated by the bleb component MLF2. MLF2 suppresses the ectopic accumulation of FG-nucleoporins and modulates the selective properties and size of condensates in vitro. Our study identifies dual mechanisms of proteotoxicity in the context of condensate formation and establishes FG-nucleoporin-directed activities for a nuclear chaperone network.
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4
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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: 2] [Impact Index Per Article: 1.0] [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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5
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Sučec I, Bersch B, Schanda P. How do Chaperones Bind (Partly) Unfolded Client Proteins? Front Mol Biosci 2021; 8:762005. [PMID: 34760928 PMCID: PMC8573040 DOI: 10.3389/fmolb.2021.762005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/06/2021] [Indexed: 01/03/2023] Open
Abstract
Molecular chaperones are central to cellular protein homeostasis. Dynamic disorder is a key feature of the complexes of molecular chaperones and their client proteins, and it facilitates the client release towards a folded state or the handover to downstream components. The dynamic nature also implies that a given chaperone can interact with many different client proteins, based on physico-chemical sequence properties rather than on structural complementarity of their (folded) 3D structure. Yet, the balance between this promiscuity and some degree of client specificity is poorly understood. Here, we review recent atomic-level descriptions of chaperones with client proteins, including chaperones in complex with intrinsically disordered proteins, with membrane-protein precursors, or partially folded client proteins. We focus hereby on chaperone-client interactions that are independent of ATP. The picture emerging from these studies highlights the importance of dynamics in these complexes, whereby several interaction types, not only hydrophobic ones, contribute to the complex formation. We discuss these features of chaperone-client complexes and possible factors that may contribute to this balance of promiscuity and specificity.
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Affiliation(s)
- Iva Sučec
- CEA, CNRS, Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, Grenoble, France
| | - Beate Bersch
- CEA, CNRS, Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, Grenoble, France
| | - Paul Schanda
- CEA, CNRS, Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, Grenoble, France.,Institute of Science and Technology Austria, Klosterneuburg, Austria
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6
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Fassler JS, Skuodas S, Weeks DL, Phillips BT. Protein Aggregation and Disaggregation in Cells and Development. J Mol Biol 2021; 433:167215. [PMID: 34450138 PMCID: PMC8530975 DOI: 10.1016/j.jmb.2021.167215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/01/2021] [Accepted: 08/18/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a feature of numerous neurodegenerative diseases. However, regulated, often reversible, formation of protein aggregates, also known as condensates, helps control a wide range of cellular activities including stress response, gene expression, memory, cell development and differentiation. This review presents examples of aggregates found in biological systems, how they are used, and cellular strategies that control aggregation and disaggregation. We include features of the aggregating proteins themselves, environmental factors, co-aggregates, post-translational modifications and well-known aggregation-directed activities that influence their formation, material state, stability and dissolution. We highlight the emerging roles of biomolecular condensates in early animal development, and disaggregation processing proteins that have recently been shown to play key roles in gametogenesis and embryogenesis.
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Affiliation(s)
- Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States.
| | - Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@sskuodas
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Bryan T Phillips
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@bt4phillips
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7
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Budrass L, Fahlman RP, Mok SA. Deciphering Network Crosstalk: The Current Status and Potential of miRNA Regulatory Networks on the HSP40 Molecular Chaperone Network. Front Genet 2021; 12:689922. [PMID: 34234816 PMCID: PMC8255926 DOI: 10.3389/fgene.2021.689922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/19/2021] [Indexed: 11/13/2022] Open
Abstract
Molecular chaperone networks fulfill complex roles in protein homeostasis and are essential for maintaining cell health. Hsp40s (commonly referred to as J-proteins) have critical roles in development and are associated with a variety of human diseases, yet little is known regarding the J-proteins with respect to the post-transcriptional mechanisms that regulate their expression. With relatively small alterations in their abundance and stoichiometry altering their activity, post-transcriptional regulation potentially has significant impact on the functions of J-proteins. MicroRNAs (miRNAs) are a large group of non-coding RNAs that form a complex regulatory network impacting gene expression. Here we review and investigate the current knowledge and potential intersection of miRNA regulatory networks with the J-Protein chaperone network. Analysis of datasets from the current version of TargetScan revealed a great number of predicted microRNAs targeting J-proteins compared to the limited reports of interactions to date. There are likely unstudied regulatory interactions that influence chaperone biology contained within our analysis. We go on to present some criteria for prioritizing candidate interactions including potential cooperative targeting of J-Proteins by multiple miRNAs. In summary, we offer a view on the scope of regulation of J-Proteins through miRNAs with the aim of guiding future investigations by identifying key regulatory nodes within these two complex cellular networks.
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Affiliation(s)
- Lion Budrass
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Richard P Fahlman
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.,Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Sue-Ann Mok
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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8
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McMahon S, Bergink S, Kampinga HH, Ecroyd H. DNAJB chaperones suppress destabilised protein aggregation via a region distinct from that used to inhibit amyloidogenesis. J Cell Sci 2021; 134:237814. [PMID: 33674449 DOI: 10.1242/jcs.255596] [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] [Received: 10/08/2020] [Accepted: 02/22/2021] [Indexed: 01/03/2023] Open
Abstract
Disturbances to protein homeostasis (proteostasis) can lead to protein aggregation and inclusion formation, processes associated with a variety of neurodegenerative disorders. DNAJB proteins are molecular chaperones that have been identified as potent suppressors of disease-related protein aggregation. In this work, a destabilised isoform of firefly luciferase (R188Q/R261Q Fluc; termed FlucDM) was overexpressed in cells to assess the capacity of DNAJBs to inhibit inclusion formation. Co-expression of all DNAJB proteins tested significantly inhibited the intracellular aggregation of FlucDM. Moreover, we show that DNAJB proteins suppress aggregation by supporting the Hsp70 (HSPA)-dependent degradation of FlucDM via the proteasome. The serine-rich stretch in DNAJB6 and DNAJB8, essential for preventing fibrillar aggregation, is not involved in the suppression of FlucDM inclusion formation. Conversely, deletion of the C-terminal TTK-LKS motif in DNAJB6 and DNAJB8, a region not required to suppress polyglutamine aggregation, abolished the ability to inhibit inclusion formation by FlucDM. Thus, our data suggest that DNAJB6 and DNAJB8 possess two distinct regions for binding substrates, one that is responsible for binding β-hairpins that form during amyloid formation and another that interacts with exposed hydrophobic patches in aggregation-prone clients. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Shannon McMahon
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Steven Bergink
- University Medical Center Groningen, University of Groningen, Department of Cell Biology, 9713 AV Groningen, The Netherlands
| | - Harm H Kampinga
- University Medical Center Groningen, University of Groningen, Department of Cell Biology, 9713 AV Groningen, The Netherlands
| | - Heath Ecroyd
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
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9
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Ayala Mariscal SM, Kirstein J. J-domain proteins interaction with neurodegenerative disease-related proteins. Exp Cell Res 2021; 399:112491. [PMID: 33460589 DOI: 10.1016/j.yexcr.2021.112491] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 12/28/2022]
Abstract
HSP70 chaperones, J-domain proteins (JDPs) and nucleotide exchange factors (NEF) form functional networks that have the ability to prevent and reverse the aggregation of proteins associated with neurodegenerative diseases. JDPs can interact with specific substrate proteins, hold them in a refolding-competent conformation and target them to specific HSP70 chaperones for remodeling. Thereby, JDPs select specific substrates and constitute an attractive target for pharmacological intervention of neurodegenerative diseases. This, under the condition that the exact mechanism of JDPs interaction with specific substrates is unveiled. In this review, we provide an overview of the structural and functional variety of JDPs that interact with neurodegenerative disease-associated proteins and we highlight those studies that identified specific residues, domains or regions of JDPs that are crucial for substrate binding.
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Affiliation(s)
- Sara María Ayala Mariscal
- Leibniz Research Institute for Molecular Pharmacology Im Forschungsverbund Berlin e.V., R.-Roessle-Strasse 10, 13125, Berlin, Germany
| | - Janine Kirstein
- Leibniz Research Institute for Molecular Pharmacology Im Forschungsverbund Berlin e.V., R.-Roessle-Strasse 10, 13125, Berlin, Germany; University of Bremen, Faculty 2, Cell Biology, Leobener Strasse, 28359, Bremen, Germany.
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10
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Joshi N, Raveendran A, Nagotu S. Chaperones and Proteostasis: Role in Parkinson's Disease. Diseases 2020; 8:diseases8020024. [PMID: 32580484 PMCID: PMC7349525 DOI: 10.3390/diseases8020024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 02/07/2023] Open
Abstract
Proper folding to attain a defined three-dimensional structure is a prerequisite for the functionality of a protein. Improper folding that eventually leads to formation of protein aggregates is a hallmark of several neurodegenerative disorders. Loss of protein homeostasis triggered by cellular stress conditions is a major contributing factor for the formation of these toxic aggregates. A conserved class of proteins called chaperones and co-chaperones is implicated in maintaining the cellular protein homeostasis. Expanding the body of evidence highlights the role of chaperones as central mediators in the formation, de-aggregation and degradation of the aggregates. Altered expression and function of chaperones is associated with many neurodegenerative diseases including Parkinson’s disease. Several studies indicate that chaperones are at the center of the cause and effect cycle of this disease. An overview of the various chaperones that are associated with homeostasis of Parkinson’s disease-related proteins and their role in pathogenicity will be discussed in this review.
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11
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Serlidaki D, van Waarde MAWH, Rohland L, Wentink AS, Dekker SL, Kamphuis MJ, Boertien JM, Brunsting JF, Nillegoda NB, Bukau B, Mayer MP, Kampinga HH, Bergink S. Functional diversity between HSP70 paralogs caused by variable interactions with specific co-chaperones. J Biol Chem 2020; 295:7301-7316. [PMID: 32284329 PMCID: PMC7247296 DOI: 10.1074/jbc.ra119.012449] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
Heat shock protein 70 (HSP70) chaperones play a central role in protein quality control and are crucial for many cellular processes, including protein folding, degradation, and disaggregation. Human HSP70s compose a family of 13 members that carry out their functions with the aid of even larger families of co-chaperones. A delicate interplay between HSP70s and co-chaperone recruitment is thought to determine substrate fate, yet it has been generally assumed that all Hsp70 paralogs have similar activities and are largely functionally redundant. However, here we found that when expressed in human cells, two highly homologous HSP70s, HSPA1A and HSPA1L, have opposing effects on cellular handling of various substrates. For example, HSPA1A reduced aggregation of the amyotrophic lateral sclerosis-associated protein variant superoxide dismutase 1 (SOD1)-A4V, whereas HSPA1L enhanced its aggregation. Intriguingly, variations in the substrate-binding domain of these HSP70s did not play a role in this difference. Instead, we observed that substrate fate is determined by differential interactions of the HSP70s with co-chaperones. Whereas most co-chaperones bound equally well to these two HSP70s, Hsp70/Hsp90-organizing protein (HOP) preferentially bound to HSPA1L, and the Hsp110 nucleotide-exchange factor HSPH2 preferred HSPA1A. The role of HSPH2 was especially crucial for the HSPA1A-mediated reduction in SOD1-A4V aggregation. These findings reveal a remarkable functional diversity at the level of the cellular HSP70s and indicate that this diversity is defined by their affinities for specific co-chaperones such as HSPH2.
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Affiliation(s)
- Despina Serlidaki
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Maria A W H van Waarde
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Lukas Rohland
- Center for Molecular Biology of the University of Heidelberg and the German Cancer Research Center, 69120 Heidelberg, Germany
| | - Anne S Wentink
- Center for Molecular Biology of the University of Heidelberg and the German Cancer Research Center, 69120 Heidelberg, Germany
| | - Suzanne L Dekker
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Maarten J Kamphuis
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Jeffrey M Boertien
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Jeanette F Brunsting
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Nadinath B Nillegoda
- Center for Molecular Biology of the University of Heidelberg and the German Cancer Research Center, 69120 Heidelberg, Germany; Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg and the German Cancer Research Center, 69120 Heidelberg, Germany
| | - Matthias P Mayer
- Center for Molecular Biology of the University of Heidelberg and the German Cancer Research Center, 69120 Heidelberg, Germany
| | - Harm H Kampinga
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands.
| | - Steven Bergink
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands.
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12
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Abstract
Ageing is a major risk factor for the development of many diseases, prominently including neurodegenerative disorders such as Alzheimer disease and Parkinson disease. A hallmark of many age-related diseases is the dysfunction in protein homeostasis (proteostasis), leading to the accumulation of protein aggregates. In healthy cells, a complex proteostasis network, comprising molecular chaperones and proteolytic machineries and their regulators, operates to ensure the maintenance of proteostasis. These factors coordinate protein synthesis with polypeptide folding, the conservation of protein conformation and protein degradation. However, sustaining proteome balance is a challenging task in the face of various external and endogenous stresses that accumulate during ageing. These stresses lead to the decline of proteostasis network capacity and proteome integrity. The resulting accumulation of misfolded and aggregated proteins affects, in particular, postmitotic cell types such as neurons, manifesting in disease. Recent analyses of proteome-wide changes that occur during ageing inform strategies to improve proteostasis. The possibilities of pharmacological augmentation of the capacity of proteostasis networks hold great promise for delaying the onset of age-related pathologies associated with proteome deterioration and for extending healthspan.
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13
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Neuromuscular Diseases Due to Chaperone Mutations: A Review and Some New Results. Int J Mol Sci 2020; 21:ijms21041409. [PMID: 32093037 PMCID: PMC7073051 DOI: 10.3390/ijms21041409] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle and the nervous system depend on efficient protein quality control, and they express chaperones and cochaperones at high levels to maintain protein homeostasis. Mutations in many of these proteins cause neuromuscular diseases, myopathies, and hereditary motor and sensorimotor neuropathies. In this review, we cover mutations in DNAJB6, DNAJB2, αB-crystallin (CRYAB, HSPB5), HSPB1, HSPB3, HSPB8, and BAG3, and discuss the molecular mechanisms by which they cause neuromuscular disease. In addition, previously unpublished results are presented, showing downstream effects of BAG3 p.P209L on DNAJB6 turnover and localization.
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14
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Palmio J, Jonson PH, Inoue M, Sarparanta J, Bengoechea R, Savarese M, Vihola A, Jokela M, Nakagawa M, Noguchi S, Olivé M, Masingue M, Kerty E, Hackman P, Weihl CC, Nishino I, Udd B. Mutations in the J domain of DNAJB6 cause dominant distal myopathy. Neuromuscul Disord 2019; 30:38-46. [PMID: 31955980 DOI: 10.1016/j.nmd.2019.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/13/2019] [Accepted: 11/15/2019] [Indexed: 01/28/2023]
Abstract
Eight patients from five families with undiagnosed dominant distal myopathy underwent clinical, neurophysiological and muscle biopsy examinations. Molecular genetic studies were performed using targeted sequencing of all known myopathy genes followed by segregation of the identified mutations in the affected families using Sanger sequencing. Two novel mutations in DNAJB6 J domain, c.149C>T (p.A50V) and c.161A>C (p.E54A), were identified as the cause of disease. The muscle involvement with p.A50V was distal calf-predominant, and the p.E54A was more proximo-distal. Histological findings were similar to those previously reported in DNAJB6 myopathy. In line with reported pathogenic mutations in the glycine/phenylalanine (G/F) domain of DNAJB6, both the novel mutations showed reduced anti-aggregation capacity by filter trap assay and TDP-43 disaggregation assays. Modeling of the protein showed close proximity of the mutated residues with the G/F domain. Myopathy-causing mutations in DNAJB6 are not only located in the G/F domain, but also in the J domain. The identified mutations in the J domain cause dominant distal and proximo-distal myopathy, confirming that mutations in DNAJB6 should be considered in distal myopathy cases.
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Affiliation(s)
- Johanna Palmio
- Neuromuscular Research Center, Tampere University Hospital and Tampere University, P.O. box 100, FIN-33014 Tampere, Finland.
| | - Per Harald Jonson
- Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
| | - Michio Inoue
- National Center of Neurology and Psychiatry (NCNP), Department of Neuromuscular Research, National Institute of Neuroscience, Tokyo, Japan
| | - Jaakko Sarparanta
- Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
| | - Rocio Bengoechea
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
| | - Anna Vihola
- Neuromuscular Research Center, Tampere University Hospital and Tampere University, P.O. box 100, FIN-33014 Tampere, Finland; Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
| | - Manu Jokela
- Neuromuscular Research Center, Tampere University Hospital and Tampere University, P.O. box 100, FIN-33014 Tampere, Finland; Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Masanori Nakagawa
- North Medical Center, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Satoru Noguchi
- National Center of Neurology and Psychiatry (NCNP), Department of Neuromuscular Research, National Institute of Neuroscience, Tokyo, Japan
| | - Montse Olivé
- Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Barcelona, Spain
| | - Marion Masingue
- University Hospital of Salpêtrière, UPMC, Institute of Myology, National Reference Center for Neuromuscular Disorders, Paris, France
| | - Emilia Kerty
- Department of Neurology, Oslo University Hospital, Rikshospitalet, University of Oslo, Oslo, Norway
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
| | - Conrad C Weihl
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Ichizo Nishino
- National Center of Neurology and Psychiatry (NCNP), Department of Neuromuscular Research, National Institute of Neuroscience, Tokyo, Japan
| | - Bjarne Udd
- Neuromuscular Research Center, Tampere University Hospital and Tampere University, P.O. box 100, FIN-33014 Tampere, Finland; Folkhälsan Research Center, Helsinki, Finland and University of Helsinki, Medicum, Helsinki, Finland
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15
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Deshayes N, Arkan S, Hansen C. The Molecular Chaperone DNAJB6, but Not DNAJB1, Suppresses the Seeded Aggregation of Alpha-Synuclein in Cells. Int J Mol Sci 2019; 20:ijms20184495. [PMID: 31514384 PMCID: PMC6769935 DOI: 10.3390/ijms20184495] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/07/2019] [Accepted: 09/08/2019] [Indexed: 11/16/2022] Open
Abstract
Alpha-synuclein (α-Syn) can misfold and aggregate, causing the degeneration of dopaminergic neurons, as seen in Parkinson’s disease (PD). We recently demonstrated that DNAJB6, a co-chaperone found in Lewy bodies (LB), suppresses the aggregation of α-Syn in cells and in vitro. In this study, we compared the capacities of DNAJB1 and DNAJB6 to suppress the seeded α-Syn aggregation in HEK293 cells expressing α-Syn tagged with cyan fluorescent protein (CFP) or yellow fluorescent protein (YFP). The aggregation of α-Syn was seeded by the transfection of the cells with recombinant α-Syn pre-formed fibrils (PFFs), following the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9-mediated knockout (KO) of these two genes, respectively. We quantified the α-Syn aggregation by fluorescence microscopy and fluorescence resonance energy transfer (FRET) analysis. We detected significantly more aggregates in the DNAJB6 KO cells compared with the parental cells, whereas the DNAJB1 KO had no effect on the α-Syn aggregation. This is the first evidence that DNAJB6 can suppress α-Syn aggregation, induced by exogenous α-Syn seeds, in cells. Next, we explored whether this mechanism could be dependent on protein degradation pathways. We observed that the increase in the α-Syn PFF-induced aggregation in the DNAJB6 KO cells compared with the parental cells was strongly diminished upon the incubation of the cells with the proteasomal inhibitor MG132. These results consolidate that DNAJB6 is a suppressor of α-Syn aggregation, and suggest that DNAJB6 may target misfolded and/or aggregated α-Syn for proteasomal degradation.
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Affiliation(s)
- Natasja Deshayes
- Molecular Neurobiology, Department of Experimental Medical Science, BMC B11, Lund University, 221 84 Lund, Sweden.
| | - Sertan Arkan
- Molecular Neurobiology, Department of Experimental Medical Science, BMC B11, Lund University, 221 84 Lund, Sweden.
| | - Christian Hansen
- Molecular Neurobiology, Department of Experimental Medical Science, BMC B11, Lund University, 221 84 Lund, Sweden.
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16
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Jung-Kc K, Himmelreich N, Prestegård KS, Shi TJS, Scherer T, Ying M, Jorge-Finnigan A, Thöny B, Blau N, Martinez A. Phenylalanine hydroxylase variants interact with the co-chaperone DNAJC12. Hum Mutat 2019; 40:483-494. [PMID: 30667134 DOI: 10.1002/humu.23712] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/12/2019] [Accepted: 01/19/2019] [Indexed: 12/13/2022]
Abstract
DNAJC12, a type III member of the HSP40/DNAJ family, has been identified as the specific co-chaperone of phenylalanine hydroxylase (PAH) and the other aromatic amino acid hydroxylases. DNAJ proteins work together with molecular chaperones of the HSP70 family to assist in proper folding and maintenance of intracellular stability of their clients. Autosomal recessive mutations in DNAJC12 were found to reduce PAH levels, leading to hyperphenylalaninemia (HPA) in patients without mutations in PAH. In this work, we investigated the interaction of normal wild-type DNAJC12 with mutant PAH in cells expressing several PAH variants associated with HPA in humans, as well as in the Enu1/1 mouse model, homozygous for the V106A-Pah variant, which leads to severe protein instability, accelerated PAH degradation and mild HPA. We found that mutant PAH exhibits increased ubiquitination, instability, and aggregation compared with normal PAH. In mouse liver lysates, we showed that DNAJC12 interacts with monoubiquitin-tagged PAH. This form represented a major fraction of PAH in the Enu1/1 but was also present in liver of wild-type PAH mice. Our results support a role of DNAJC12 in the processing of misfolded ubiquitinated PAH by the ubiquitin-dependent proteasome/autophagy systems and add to the evidence that the DNAJ proteins are important players both for proper folding and degradation of their clients.
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Affiliation(s)
- Kunwar Jung-Kc
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | | | | | - Tanja Scherer
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Ming Ying
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Beat Thöny
- Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Nenad Blau
- Dietmar-Hopp-Metabolic Center, University Children's Hospital, Heidelberg, Germany.,Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Bergen, Norway
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17
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Fernández-Higuero JÁ, Betancor-Fernández I, Mesa-Torres N, Muga A, Salido E, Pey AL. Structural and functional insights on the roles of molecular chaperones in the mistargeting and aggregation phenotypes associated with primary hyperoxaluria type I. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 114:119-152. [PMID: 30635080 DOI: 10.1016/bs.apcsb.2018.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To carry out their biological function in cells, proteins must be folded and targeted to the appropriate subcellular location. These processes are controlled by a vast collection of interacting proteins collectively known as the protein homeostasis network, in which molecular chaperones play a prominent role. Protein homeostasis can be impaired by inherited mutations leading to genetic diseases. In this chapter, we focus on a particular disease, primary hyperoxaluria type 1 (PH1), in which disease-associated mutations exacerbate protein aggregation in the cell and mistarget the peroxisomal alanine:glyoxylate aminotransferase (AGT) protein to mitochondria, in part due to native state destabilization and enhanced interaction with Hsp60, 70 and 90 chaperone systems. After a general introduction of molecular chaperones and PH1, we review our current knowledge on the structural and energetic features of PH1-causing mutants that lead to these particular pathogenic mechanisms. From this perspective, and in the context of the key role of molecular chaperones in PH1 pathogenesis, we present and discuss current and future perspectives for pharmacological treatments for this disease.
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Affiliation(s)
- José Ángel Fernández-Higuero
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Isabel Betancor-Fernández
- Centre for Biomedical Research on Rare Diseases (CIBERER), Hospital Universitario de Canarias, ITB, University of La Laguna, Tenerife, Spain
| | - Noel Mesa-Torres
- Department of Physical Chemistry, University of Granada, Granada, Spain
| | - Arturo Muga
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Eduardo Salido
- Centre for Biomedical Research on Rare Diseases (CIBERER), Hospital Universitario de Canarias, ITB, University of La Laguna, Tenerife, Spain
| | - Angel L Pey
- Department of Physical Chemistry, University of Granada, Granada, Spain.
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18
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Lizama BN, Palubinsky AM, McLaughlin B. Alterations in the E3 ligases Parkin and CHIP result in unique metabolic signaling defects and mitochondrial quality control issues. Neurochem Int 2018; 117:139-155. [PMID: 28851515 PMCID: PMC5826822 DOI: 10.1016/j.neuint.2017.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 08/11/2017] [Accepted: 08/21/2017] [Indexed: 01/07/2023]
Abstract
E3 ligases are essential scaffold proteins, facilitating the transfer of ubiquitin from E2 enzymes to lysine residues of client proteins via isopeptide bonds. The specificity of substrate binding and the expression and localization of E3 ligases can, however, endow these proteins with unique features with variable effects on mitochondrial, metabolic and CNS function. By comparing and contrasting two E3 ligases, Parkin and C-terminus of HSC70-Interacting protein (CHIP) we seek to highlight the biophysical properties that may promote mitochondrial dysfunction, acute stress signaling and critical developmental periods to cease in response to mutations in these genes. Encoded by over 600 human genes, RING-finger proteins are the largest class of E3 ligases. Parkin contains three RING finger domains, with R1 and R2 separated by an in-between region (IBR) domain. Loss-of-function mutations in Parkin were identified in patients with early onset Parkinson's disease. CHIP is a member of the Ubox family of E3 ligases. It contains an N-terminal TPR domain and forms unique asymmetric homodimers. While CHIP can substitute for mutated Parkin and enhance survival, CHIP also has unique functions. The differences between these proteins are underscored by the observation that unlike Parkin-deficient animals, CHIP-null animals age prematurely and have significantly impaired motor function. These properties make these E3 ligases appealing targets for clinical intervention. In this work, we discuss how biophysical and metabolic properties of these E3 ligases have driven rapid progress in identifying roles for E3 ligases in development, proteostasis, mitochondrial biology, and cell health, as well as new data about how these proteins alter the CNS proteome.
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Affiliation(s)
- Britney N Lizama
- Neuroscience Graduate Group, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States; Vanderbilt Brain Institute, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States.
| | - Amy M Palubinsky
- Neuroscience Graduate Group, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States; Vanderbilt Brain Institute, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States
| | - BethAnn McLaughlin
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States; Department of Neurology, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States; Department of Pharmacology, Vanderbilt University Medical Center, 465 21st Ave S MRB III, Nashville, TN 37240, United States
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19
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Mok SA, Condello C, Freilich R, Gillies A, Arhar T, Oroz J, Kadavath H, Julien O, Assimon VA, Rauch JN, Dunyak BM, Lee J, Tsai FTF, Wilson MR, Zweckstetter M, Dickey CA, Gestwicki JE. Mapping interactions with the chaperone network reveals factors that protect against tau aggregation. Nat Struct Mol Biol 2018; 25:384-393. [PMID: 29728653 PMCID: PMC5942583 DOI: 10.1038/s41594-018-0057-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 03/14/2018] [Indexed: 12/31/2022]
Abstract
A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease.
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Affiliation(s)
- Sue-Ann Mok
- Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
| | - Carlo Condello
- Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
| | - Rebecca Freilich
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Anne Gillies
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Taylor Arhar
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Javier Oroz
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Göttingen, Germany
| | | | - Olivier Julien
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Victoria A Assimon
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Jennifer N Rauch
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Bryan M Dunyak
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Jungsoon Lee
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Francis T F Tsai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Mark R Wilson
- llawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Markus Zweckstetter
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Göttingen, Germany
- Max-Planck-Institut für Biophysikalische Chemie, Goettingen, Germany
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Göttingen, Germany
| | - Chad A Dickey
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL, USA
| | - Jason E Gestwicki
- Department of Neurology, University of California at San Francisco, San Francisco, CA, USA.
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA.
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20
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Zarouchlioti C, Parfitt DA, Li W, Gittings LM, Cheetham ME. DNAJ Proteins in neurodegeneration: essential and protective factors. Philos Trans R Soc Lond B Biol Sci 2018; 373:20160534. [PMID: 29203718 PMCID: PMC5717533 DOI: 10.1098/rstb.2016.0534] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2017] [Indexed: 12/16/2022] Open
Abstract
Maintenance of protein homeostasis is vitally important in post-mitotic cells, particularly neurons. Neurodegenerative diseases such as polyglutamine expansion disorders-like Huntington's disease or spinocerebellar ataxia (SCA), Alzheimer's disease, fronto-temporal dementia (FTD), amyotrophic lateral sclerosis (ALS) and Parkinson's disease-are often characterized by the presence of inclusions of aggregated protein. Neurons contain complex protein networks dedicated to protein quality control and maintaining protein homeostasis, or proteostasis. Molecular chaperones are a class of proteins with prominent roles in maintaining proteostasis, which act to bind and shield hydrophobic regions of nascent or misfolded proteins while allowing correct folding, conformational changes and enabling quality control. There are many different families of molecular chaperones with multiple functions in proteostasis. The DNAJ family of molecular chaperones is the largest chaperone family and is defined by the J-domain, which regulates the function of HSP70 chaperones. DNAJ proteins can also have multiple other protein domains such as ubiquitin-interacting motifs or clathrin-binding domains leading to diverse and specific roles in the cell, including targeting client proteins for degradation via the proteasome, chaperone-mediated autophagy and uncoating clathrin-coated vesicles. DNAJ proteins can also contain ER-signal peptides or mitochondrial leader sequences, targeting them to specific organelles in the cell. In this review, we discuss the multiple roles of DNAJ proteins and in particular focus on the role of DNAJ proteins in protecting against neurodegenerative diseases caused by misfolded proteins. We also discuss the role of DNAJ proteins as direct causes of inherited neurodegeneration via mutations in DNAJ family genes.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.
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Affiliation(s)
| | - David A Parfitt
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
| | - Wenwen Li
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
| | - Lauren M Gittings
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
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21
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Craig EA, Marszalek J. How Do J-Proteins Get Hsp70 to Do So Many Different Things? Trends Biochem Sci 2017; 42:355-368. [PMID: 28314505 DOI: 10.1016/j.tibs.2017.02.007] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/09/2017] [Accepted: 02/16/2017] [Indexed: 01/07/2023]
Abstract
Hsp70 chaperone machineries have pivotal roles in an array of fundamental biological processes through their facilitation of protein folding, disaggregation, and remodeling. The obligate J-protein co-chaperones of Hsp70s drive much of this remarkable multifunctionality, with most Hsp70s having multiple J-protein partners. Recent data suggest that J-protein-driven versatility is substantially due to precise localization within the cell and the specificity of substrate protein binding. However, this relatively simple view belies the intricacy of J-protein function. Examples are emerging of J-protein interactions with Hsp70s and other chaperones, as well as integration into broader cellular networks. These interactions fine-tune, in critical ways, the ability of Hsp70s to participate in diverse cellular processes.
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Affiliation(s)
- Elizabeth A Craig
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA.
| | - Jaroslaw Marszalek
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA; Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
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