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Norton J, Seah N, Santiago F, Sindi SS, Serio TR. Multiple aspects of amyloid dynamics in vivo integrate to establish prion variant dominance in yeast. Front Mol Neurosci 2024; 17:1439442. [PMID: 39139213 PMCID: PMC11319303 DOI: 10.3389/fnmol.2024.1439442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 07/15/2024] [Indexed: 08/15/2024] Open
Abstract
Prion variants are self-perpetuating conformers of a single protein that assemble into amyloid fibers and confer unique phenotypic states. Multiple prion variants can arise, particularly in response to changing environments, and interact within an organism. These interactions are often competitive, with one variant establishing phenotypic dominance over the others. This dominance has been linked to the competition for non-prion state protein, which must be converted to the prion state via a nucleated polymerization mechanism. However, the intrinsic rates of conversion, determined by the conformation of the variant, cannot explain prion variant dominance, suggesting a more complex interaction. Using the yeast prion system [PSI+ ], we have determined the mechanism of dominance of the [PSI+ ]Strong variant over the [PSI+ ]Weak variant in vivo. When mixed by mating, phenotypic dominance is established in zygotes, but the two variants persist and co-exist in the lineage descended from this cell. [PSI+ ]Strong propagons, the heritable unit, are amplified at the expense of [PSI+ ]Weak propagons, through the efficient conversion of soluble Sup35 protein, as revealed by fluorescence photobleaching experiments employing variant-specific mutants of Sup35. This competition, however, is highly sensitive to the fragmentation of [PSI+ ]Strong amyloid fibers, with even transient inhibition of the fragmentation catalyst Hsp104 promoting amplification of [PSI+ ]Weak propagons. Reducing the number of [PSI+ ]Strong propagons prior to mating, similarly promotes [PSI+ ]Weak amplification and conversion of soluble Sup35, indicating that template number and conversion efficiency combine to determine dominance. Thus, prion variant dominance is not an absolute hierarchy but rather an outcome arising from the dynamic interplay between unique protein conformations and their interactions with distinct cellular proteostatic niches.
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Affiliation(s)
- Jennifer Norton
- Department of Molecular and Cellular Biology, The University of Arizona, Tucson, AZ, United States
| | - Nicole Seah
- Department of Biochemistry, The University of Washington, Seattle, WA, United States
| | - Fabian Santiago
- Department of Applied Mathematics, The University of California, Merced, Merced, CA, United States
| | - Suzanne S. Sindi
- Department of Applied Mathematics, The University of California, Merced, Merced, CA, United States
| | - Tricia R. Serio
- Department of Biochemistry, The University of Washington, Seattle, WA, United States
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2
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Ganser SJ, McNish BA, Schwanitz GL, Delaney JL, Corpus BA, Schilke BA, Biswal AK, Sahi C, Craig EA, Hines JK. Unique characteristics of the J-domain proximal regions of Hsp70 cochaperone Apj1 in prion propagation/elimination and its overlap with Sis1 function. Front Mol Biosci 2024; 11:1392608. [PMID: 38721277 PMCID: PMC11078019 DOI: 10.3389/fmolb.2024.1392608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 03/27/2024] [Indexed: 09/05/2024] Open
Abstract
J-domain proteins (JDPs) are obligate cochaperones of Hsp70s. The Class A JDP Apj1 of the yeast cytosol has an unusually complex region between the N-terminal J-domain and the substrate binding region-often called the Grich or GF region in Class A and B JDPs because of its typical abundance of glycine. The N-terminal 161-residue Apj1 fragment is known to be sufficient for Apj1 function in prion curing, driven by the overexpression of Hsp104. Further analyzing the N-terminal segment of Apj1, we found that a 90-residue fragment that includes the 70-residue J-domain and the adjacent 12-residue glutamine/alanine (Q/A) segment is sufficient for curing. Furthermore, the 121-residue fragment that includes the Grich region was sufficient to not only sustain the growth of cells lacking the essential Class B JDP Sis1 but also enabled the maintenance of several prions normally dependent on Sis1 for propagation. A J-domain from another cytosolic JDP could substitute for the Sis1-related functions but not for Apj1 in prion curing. Together, these results separate the functions of JDPs in prion biology and underscore the diverse functionality of multi-domain cytosolic JDPs in yeast.
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Affiliation(s)
| | - Bridget A. McNish
- Department of Chemistry, Lafayette College, Easton, PA, United States
| | | | - John L. Delaney
- Department of Chemistry, Lafayette College, Easton, PA, United States
| | - Bridget A. Corpus
- Department of Chemistry, Lafayette College, Easton, PA, United States
| | - Brenda A. Schilke
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI, United States
| | - Anup K. Biswal
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Elizabeth A. Craig
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI, United States
| | - Justin K. Hines
- Department of Chemistry, Lafayette College, Easton, PA, United States
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3
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Marszalek J, De Los Rios P, Cyr D, Mayer MP, Adupa V, Andréasson C, Blatch GL, Braun JEA, Brodsky JL, Bukau B, Chapple JP, Conz C, Dementin S, Genevaux P, Genest O, Goloubinoff P, Gestwicki J, Hammond CM, Hines JK, Ishikawa K, Joachimiak LA, Kirstein J, Liberek K, Mokranjac D, Nillegoda N, Ramos CHI, Rebeaud M, Ron D, Rospert S, Sahi C, Shalgi R, Tomiczek B, Ushioda R, Ustyantseva E, Ye Y, Zylicz M, Kampinga HH. J-domain proteins: From molecular mechanisms to diseases. Cell Stress Chaperones 2024; 29:21-33. [PMID: 38320449 PMCID: PMC10939069 DOI: 10.1016/j.cstres.2023.12.002] [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: 12/04/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 02/08/2024] Open
Abstract
J-domain proteins (JDPs) are the largest family of chaperones in most organisms, but much of how they function within the network of other chaperones and protein quality control machineries is still an enigma. Here, we report on the latest findings related to JDP functions presented at a dedicated JDP workshop in Gdansk, Poland. The report does not include all (details) of what was shared and discussed at the meeting, because some of these original data have not yet been accepted for publication elsewhere or represented still preliminary observations at the time.
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Affiliation(s)
- Jaroslaw Marszalek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Paolo De Los Rios
- Institute of Physics, School of Basic Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland; Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland
| | - Douglas Cyr
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Vasista Adupa
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm S-10691, Sweden
| | - Gregory L Blatch
- Biomedical Research and Drug Discovery Research Group, Faculty of Health Sciences, Higher Colleges of Technology, Sharjah, United Arab Emirates; The Vice Chancellery, The University of Notre Dame Australia, Fremantle, Western Australia, Australia; Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Janice E A Braun
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - J Paul Chapple
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Charlotte Conz
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sébastien Dementin
- Aix Marseille Univ, CNRS, BIP UMR 7281, IMM, 31 Chemin Joseph Aiguier, Marseille 13402, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Olivier Genest
- Aix Marseille Univ, CNRS, BIP UMR 7281, IMM, 31 Chemin Joseph Aiguier, Marseille 13402, France
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Faculty of Biology and Medicine, Lausanne University, Lausanne 1015, Switzerland
| | - Jason Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA 94308, USA
| | - Colin M Hammond
- Novo Nordisk Foundation Center for Protein Research (CPR), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Molecular & Clinical Cancer Medicine, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Justin K Hines
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | - Koji Ishikawa
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX, USA; Peter O'Donnell Jr Brain Institute, UT Southwestern Medical Center, Dallas, TX, USA
| | - Janine Kirstein
- Leibniz Institute on Aging - Fritz Lipmann Institute and Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, Jena 07745, Germany
| | - Krzysztof Liberek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Dejana Mokranjac
- LMU Munich, Biocenter-Cell Biology, Großhadernerstr. 2, Planegg-Martinsried 82152, Germany
| | - Nadinath Nillegoda
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia; Centre for Dementia and Brain Repair at the Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia
| | - Carlos H I Ramos
- Institute of Chemistry, University of Campinas-UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Mathieu Rebeaud
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland
| | - David Ron
- University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Bhopal, Madhya Pradesh, India; IISER Bhopal, Room Number 117, AB3, Bhopal Bypass Road, Bhopal 462066, Madhya Pradesh, India
| | - Reut Shalgi
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Bartlomiej Tomiczek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Ryo Ushioda
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Elizaveta Ustyantseva
- Department of Biomedical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Yihong Ye
- National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maciej Zylicz
- Foundation for Polish Science, Warsaw 02-611, Poland
| | - Harm H Kampinga
- Department of Biomedical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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4
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Tak Y, Lal SS, Gopan S, Balakrishnan M, Satheesh G, Biswal AK, Verma AK, Cole SJ, Brown RE, Hayward RE, Hines JK, Sahi C. Identification of subfunctionalized aggregate-remodeling J-domain proteins in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:1705-1722. [PMID: 36576197 PMCID: PMC10010614 DOI: 10.1093/jxb/erac514] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
J-domain proteins (JDPs) are critical components of the cellular protein quality control machinery, playing crucial roles in preventing the formation and, solubilization of cytotoxic protein aggregates. Bacteria, yeast, and plants additionally have large, multimeric heat shock protein 100 (Hsp100)-class disaggregases that resolubilize protein aggregates. JDPs interact with aggregated proteins and specify the aggregate-remodeling activities of Hsp70s and Hsp100s. However, the aggregate-remodeling properties of plant JDPs are not well understood. Here we identify eight orthologs of Sis1 (an evolutionarily conserved Class II JDP of budding yeast) in Arabidopsis thaliana with distinct aggregate-remodeling functionalities. Six of these JDPs associate with heat-induced protein aggregates in vivo and co-localize with Hsp101 at heat-induced protein aggregate centers. Consistent with a role in solubilizing cytotoxic protein aggregates, an atDjB3 mutant had defects in both solubilizing heat-induced aggregates and acquired thermotolerance as compared with wild-type seedlings. Next, we used yeast prions as protein aggregate models to show that the six JDPs have distinct aggregate-remodeling properties. Results presented in this study, as well as findings from phylogenetic analysis, demonstrate that plants harbor multiple, evolutionarily conserved JDPs with capacity to process a variety of protein aggregate conformers induced by heat and other stressors.
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Affiliation(s)
- Yogesh Tak
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Silviya S Lal
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Shilpa Gopan
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Madhumitha Balakrishnan
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Gouri Satheesh
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Anup K Biswal
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Amit K Verma
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
| | - Sierra J Cole
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | | | | | - Justin K Hines
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, India
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5
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Miller SC, Wegrzynowicz AK, Cole SJ, Hayward RE, Ganser SJ, Hines JK. Hsp40/JDP Requirements for the Propagation of Synthetic Yeast Prions. Viruses 2022; 14:v14102160. [PMID: 36298715 PMCID: PMC9611480 DOI: 10.3390/v14102160] [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: 07/28/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022] Open
Abstract
Yeast prions are protein-based transmissible elements, most of which are amyloids. The chaperone protein network in yeast is inexorably linked to the spreading of prions during cell division by fragmentation of amyloid prion aggregates. Specifically, the core “prion fragmentation machinery” includes the proteins Hsp104, Hsp70 and the Hsp40/J-domain protein (JDP) Sis1. Numerous novel amyloid-forming proteins have been created and examined in the yeast system and occasionally these amyloids are also capable of continuous Hsp104-dependent propagation in cell populations, forming synthetic prions. However, additional chaperone requirements, if any, have not been determined. Here, we report the first instances of a JDP-Hsp70 system requirement for the propagation of synthetic prions. We utilized constructs from a system of engineered prions with prion-forming domains (PrDs) consisting of a polyQ stretch interrupted by a single heterologous amino acid interspersed every fifth residue. These “polyQX” PrDs are fused to the MC domains of Sup35, creating chimeric proteins of which a subset forms synthetic prions in yeast. For four of these prions, we show that SIS1 repression causes prion loss in a manner consistent with Sis1′s known role in prion fragmentation. PolyQX prions were sensitive to Sis1 expression levels to differing degrees, congruent with the variability observed among native prions. Our results expand the scope known Sis1 functionality, demonstrating that Sis1 acts on amyloids broadly, rather than through specific protein–protein interactions with individual yeast prion-forming proteins.
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6
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Wu S, Yin Y, Du L. FUS aggregation following ischemic stroke favors brain astrocyte activation through inducing excessive autophagy. Exp Neurol 2022; 355:114144. [PMID: 35718207 DOI: 10.1016/j.expneurol.2022.114144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/25/2022] [Accepted: 06/13/2022] [Indexed: 11/04/2022]
Abstract
As is the case with neurodegenerative diseases, abnormal accumulation of aggregated proteins in neurons and glial are also known to implicate in the pathogenesis of ischemic stroke. However, the potential role of protein aggregates in brain ischemia remains largely unknown. Fused in Sarcoma (FUS) protein has a vital role in RNA metabolism and regulating cellular homeostasis. FUS pathology has been demonstrated in the formation of toxic aggregates and critically affecting cell viability in neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but whether this also applies to neurological injury following cerebral ischemia is unclear. Herein, we demonstrated a critical role of aggregated FUS in astrocyte activation caused by cerebral ischemia and a possible underlying molecular mechanism. Cerebral ischemic injury significantly induced the formation of cytoplasmic FUS aggregates in reactive astrocytes and injured neurons, thereby aggravating neurofunctional damages and worsening stroke outcomes. Further analysis revealed that extranuclear aggregation of FUS in astrocytes was involved in the induction of excessive autophagy, which contributes to autophagic cell injury or death. In conclusion, our results reveal the important contribution of FUS aggregates in promoting astrocyte activation in stroke pathology independent of its transcriptional regulation activity. We thus propose that aggregation of FUS is an important pathological process in ischemic stroke and targeting FUS aggregates might be of unique therapeutic value in the development of future treatment strategies for ischemic stroke.
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Affiliation(s)
- Shusheng Wu
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yuye Yin
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Longfei Du
- Department of Laboratory Medicine, Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu, China.
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7
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Differential Interactions of Molecular Chaperones and Yeast Prions. J Fungi (Basel) 2022; 8:jof8020122. [PMID: 35205876 PMCID: PMC8877571 DOI: 10.3390/jof8020122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 02/01/2023] Open
Abstract
Baker’s yeast Saccharomyces cerevisiae is an important model organism that is applied to study various aspects of eukaryotic cell biology. Prions in yeast are self-perpetuating heritable protein aggregates that can be leveraged to study the interaction between the protein quality control (PQC) machinery and misfolded proteins. More than ten prions have been identified in yeast, of which the most studied ones include [PSI+], [URE3], and [PIN+]. While all of the major molecular chaperones have been implicated in propagation of yeast prions, many of these chaperones differentially impact propagation of different prions and/or prion variants. In this review, we summarize the current understanding of the life cycle of yeast prions and systematically review the effects of different chaperone proteins on their propagation. Our analysis clearly shows that Hsp40 proteins play a central role in prion propagation by determining the fate of prion seeds and other amyloids. Moreover, direct prion-chaperone interaction seems to be critically important for proper recruitment of all PQC components to the aggregate. Recent results also suggest that the cell asymmetry apparatus, cytoskeleton, and cell signaling all contribute to the complex network of prion interaction with the yeast cell.
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8
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Abrams J, Arhar T, Mok SA, Taylor IR, Kampmann M, Gestwicki JE. Functional genomics screen identifies proteostasis targets that modulate prion protein (PrP) stability. Cell Stress Chaperones 2021; 26:443-452. [PMID: 33547632 PMCID: PMC7925731 DOI: 10.1007/s12192-021-01191-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/14/2022] Open
Abstract
Prion protein (PrP) adopts either a helical conformation (PrPC) or an alternative, beta sheet-rich, misfolded conformation (PrPSc). The PrPSc form has the ability to "infect" PrPC and force it into the misfolded state. Accumulation of PrPSc is associated with a number of lethal neurodegenerative disorders, including Creutzfeldt-Jacob disease (CJD). Knockout of PrPC protects cells and animals from PrPSc infection; thus, there is interest in identifying factors that regulate PrPC stability, with the therapeutic goal of reducing PrPC levels and limiting infection by PrPSc. Here, we assembled a short-hairpin RNA (shRNA) library composed of 25+ shRNA sequences for each of 133 protein homeostasis (aka proteostasis) factors, such as molecular chaperones and co-chaperones. This Proteostasis shRNA Library was used to identify regulators of PrPC stability in HEK293 Hu129M cells. Strikingly, the screen identified a number of Hsp70 family members and their co-chaperones as putative targets. Indeed, a chemical pan-inhibitor of Hsp70s reduced PrPC levels and limited conversion to PrPSc in N2a cells. These results implicate specific proteostasis sub-networks, especially the Hsp70 system, as potential new targets for the treatment of CJD. More broadly, the Proteostasis shRNA Library might be a useful tool for asking which proteostasis factors are important for a given protein.
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Affiliation(s)
- Jennifer Abrams
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA
| | - Taylor Arhar
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA
| | - Sue Ann Mok
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA
| | - Isabelle R Taylor
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA
| | - Martin Kampmann
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA.
- Institute for Neurodegenerative Disease, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA.
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9
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Shoup D, Priola SA. The Size and Stability of Infectious Prion Aggregates Fluctuate Dynamically during Cellular Uptake and Disaggregation. Biochemistry 2021; 60:398-411. [PMID: 33497187 DOI: 10.1021/acs.biochem.0c00923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Prion diseases arise when PrPSc, an aggregated, infectious, and insoluble conformer of the normally soluble mammalian prion protein, PrPC, catalyzes the conversion of PrPC into more PrPSc, which then accumulates in the brain leading to disease. PrPSc is the primary, if not sole, component of the infectious prion. Despite the stability and protease insensitivity of PrPSc aggregates, they can be degraded after cellular uptake. However, how cells disassemble and degrade PrPSc is poorly understood. In this work, we analyzed how the protease sensitivity and size distribution of PrPSc aggregates from two different mouse-adapted prion strains, 22L, that can persistently infect cells and 87V, that cannot, changed during cellular uptake. We show that within the first 4 h following uptake large PrPSc aggregates from both prion strains become less resistant to digestion by proteinase K (PK) through a mechanism that is dependent upon the acidic environment of endocytic vesicles. We further show that during disassembly, PrPSc aggregates from both strains become more resistant to PK digestion through the apparent removal of protease-sensitive PrPSc, with PrPSc from the 87V strain disassembled more readily than PrPSc from the 22L strain. Taken together, our data demonstrate that the sizes and stabilities of PrPSc from different prion strains change during cellular uptake and degradation, thereby potentially impacting the ability of prions to infect cells.
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Affiliation(s)
- Daniel Shoup
- Rocky Mountain Laboratories, Laboratory of Persistent Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, United States
| | - Suzette A Priola
- Rocky Mountain Laboratories, Laboratory of Persistent Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, United States
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10
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Huang YW, Kushnirov VV, King CY. Mutable yeast prion variants are stabilized by a defective Hsp104 chaperone. Mol Microbiol 2020; 115:774-788. [PMID: 33190361 DOI: 10.1111/mmi.14643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 11/30/2022]
Abstract
Gorkovskiy et al. observed that many [PSI+ ] prion isolates, obtained in yeast with the mutant Hsp104T160M chaperone, propagate poorly in wild-type cells and suggested that Hsp104 is part of the cellular anti-prion system, curing many nascent [PSI+ ] variants. Here, we argue that the concept may require reassessment. We induced [PSI+ ] variants in both the wild-type and the mutant background. Three new variants were isolated in the T160M background. They exhibited lower thermostability, possessed novel structural features, and were inherently mutable, changing to well-characterized VH, VK, and VL variants in wild-type cells. In contrast, VH, VK, and VL of the wild-type background, could not change freely and were lost in the mutant, due to insufficient chaperone activity. Thus, mutant Hsp104 can impose as much restriction against emerging prion variants as the wild-type protein. Such restriction conserved the transmutable variants in the T160M background, since new structures mis-templated from them could not gain a foothold. We further demonstrate excess Hsp104T160M or Hsp104∆2-147 can eliminate nearly all of the [PSI+ ] variants in their native background. This finding contradicts the generally held belief that Hsp104-induced [PSI+ ] curing requires its N-terminal domain, and may help settling the current contention regarding how excess Hsp104 cures [PSI+ ].
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Affiliation(s)
- Yu-Wen Huang
- Molecular Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Vitaly V Kushnirov
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow, Russia
| | - Chih-Yen King
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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11
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Mechanisms for Curing Yeast Prions. Int J Mol Sci 2020; 21:ijms21186536. [PMID: 32906758 PMCID: PMC7555348 DOI: 10.3390/ijms21186536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 11/24/2022] Open
Abstract
Prions are infectious proteins that self-propagate by changing from their normal folded conformation to a misfolded conformation. The misfolded conformation, which is typically rich in β-sheet, serves as a template to convert the prion protein into its misfolded conformation. In yeast, the misfolded prion proteins are assembled into amyloid fibers or seeds, which are constantly severed and transmitted to daughter cells. To cure prions in yeast, it is necessary to eliminate all the prion seeds. Multiple mechanisms of curing have been found including inhibiting severing of the prion seeds, gradual dissolution of the prion seeds, asymmetric segregation of the prion seeds between mother and daughter cells during cell division, and degradation of the prion seeds. These mechanisms, achieved by using different protein quality control machinery, are not mutually exclusive; depending on conditions, multiple mechanisms may work simultaneously to achieve curing. This review discusses the various methods that have been used to differentiate between these mechanisms of curing.
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Wickner RB, Edskes HK, Son M, Wu S, Niznikiewicz M. How Do Yeast Cells Contend with Prions? Int J Mol Sci 2020; 21:ijms21134742. [PMID: 32635197 PMCID: PMC7369894 DOI: 10.3390/ijms21134742] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
Infectious proteins (prions) include an array of human (mammalian) and yeast amyloid diseases in which a protein or peptide forms a linear β-sheet-rich filament, at least one functional amyloid prion, and two functional infectious proteins unrelated to amyloid. In Saccharomyces cerevisiae, at least eight anti-prion systems deal with pathogenic amyloid yeast prions by (1) blocking their generation (Ssb1,2, Ssz1, Zuo1), (2) curing most variants as they arise (Btn2, Cur1, Hsp104, Upf1,2,3, Siw14), and (3) limiting the pathogenicity of variants that do arise and propagate (Sis1, Lug1). Known mechanisms include facilitating proper folding of the prion protein (Ssb1,2, Ssz1, Zuo1), producing highly asymmetric segregation of prion filaments in mitosis (Btn2, Hsp104), competing with the amyloid filaments for prion protein monomers (Upf1,2,3), and regulation of levels of inositol polyphosphates (Siw14). It is hoped that the discovery of yeast anti-prion systems and elucidation of their mechanisms will facilitate finding analogous or homologous systems in humans, whose manipulation may be useful in treatment.
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13
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Barbitoff YA, Matveenko AG, Bondarev SA, Maksiutenko EM, Kulikova AV, Zhouravleva GA. Quantitative assessment of chaperone binding to amyloid aggregates identifies specificity of Hsp40 interaction with yeast prion fibrils. FEMS Yeast Res 2020; 20:5831717. [PMID: 32379306 DOI: 10.1093/femsyr/foaa025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/05/2020] [Indexed: 12/18/2022] Open
Abstract
Yeast self-perpetuating protein aggregates (yeast prions) provide a framework to investigate the interaction of misfolded proteins with the protein quality control machinery. The major component of this system that facilitates propagation of all known yeast amyloid prions is the Hsp104 chaperone that catalyzes fibril fragmentation. Overproduction of Hsp104 cures some yeast prions via a fragmentation-independent mechanism. Importantly, major cytosolic chaperones of the Hsp40 group, Sis1 and Ydj1, oppositely affect yeast prion propagation, and are capable of stimulating different activities of Hsp104. In this work, we developed a quantitative method to investigate the Hsp40 binding to amyloid aggregates. We demonstrate that Sis1 binds fibrils formed by the Sup35NM protein with higher affinity compared to Ydj1. Moreover, the interaction of Sis1 with the fibrils formed by the other yeast prion protein, Rnq1, is orders of magnitude weaker. We show that the deletion of the dimerization domain of Sis1 (crucial for the curing of [PSI+] by excess Hsp104) decreases its affinity to both Sup35NM and Rnq1 fibrils. Taken together, these results suggest that tight binding of Hsp40 to the amyloid fibrils is likely to enhance aggregate malpartition instead of fibril fragmentation.
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Affiliation(s)
- Yury A Barbitoff
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia
| | - Andrew G Matveenko
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia
| | - Stanislav A Bondarev
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia.,Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia
| | - Evgeniia M Maksiutenko
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia.,St. Petersburg Branch, Vavilov Institute of General Genetics, Russian Academy of Sciences, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia
| | - Alexandra V Kulikova
- Peter the Great St. Petersburg Polytechnic University, Politekhnicheskaya ul. 29, St. Petersburg, 195251 Russia
| | - Galina A Zhouravleva
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia.,Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034 Russia
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14
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O'Carroll A, Coyle J, Gambin Y. Prions and Prion-like assemblies in neurodegeneration and immunity: The emergence of universal mechanisms across health and disease. Semin Cell Dev Biol 2019; 99:115-130. [PMID: 31818518 DOI: 10.1016/j.semcdb.2019.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023]
Abstract
Prion-like behaviour is an abrupt process, an "all-or-nothing" transition between a monomeric species and an "infinite" fibrillated form. Once a nucleation point is formed, the process is unstoppable as fibrils self-propagate by recruiting and converting all monomers into the amyloid fold. After the "mad cow" episode, prion diseases have made the headlines, but more and more prion-like behaviours have emerged in neurodegenerative diseases, where formation of fibrils and large conglomerates of proteins deeply disrupt the cell homeostasis. More interestingly, in the last decade, examples emerged to suggest that prion-like conversion can be used as a positive gain of function, for memory storage or structural scaffolding. More recent experiments show that we are only seeing the tip of the iceberg and that, for example, prion-like amplification is found in many pathways of the immune response. In innate immunity, receptors on the cellular surface or within the cells 'sense' danger and propagate this information as signal, through protein-protein interactions (PPIs) between 'receptor', 'adaptor' and 'effector' proteins. In innate immunity, the smallest signal of a foreign element or pathogen needs to trigger a macroscopic signal output, and it was found that adaptor polymerize to create an extreme signal amplification. Interestingly, our body uses multiple structural motifs to create large signalling platform; a few innate proteins use amyloid scaffolds but most of the polymers discovered are composed by self-assembly in helical filaments. Some of these helical assemblies even have intercellular "contamination" in a "true" prion action, as demonstrated for ASC specks and MyD88 filaments. Here, we will describe the current knowledge in neurodegenerative diseases and innate immunity and show how these two very different fields can cross-seed discoveries.
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Affiliation(s)
- Ailis O'Carroll
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia
| | - Joanne Coyle
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia.
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15
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Yeast Models for Amyloids and Prions: Environmental Modulation and Drug Discovery. Molecules 2019; 24:molecules24183388. [PMID: 31540362 PMCID: PMC6767215 DOI: 10.3390/molecules24183388] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 12/11/2022] Open
Abstract
Amyloids are self-perpetuating protein aggregates causing neurodegenerative diseases in mammals. Prions are transmissible protein isoforms (usually of amyloid nature). Prion features were recently reported for various proteins involved in amyloid and neural inclusion disorders. Heritable yeast prions share molecular properties (and in the case of polyglutamines, amino acid composition) with human disease-related amyloids. Fundamental protein quality control pathways, including chaperones, the ubiquitin proteasome system and autophagy are highly conserved between yeast and human cells. Crucial cellular proteins and conditions influencing amyloids and prions were uncovered in the yeast model. The treatments available for neurodegenerative amyloid-associated diseases are few and their efficiency is limited. Yeast models of amyloid-related neurodegenerative diseases have become powerful tools for high-throughput screening for chemical compounds and FDA-approved drugs that reduce aggregation and toxicity of amyloids. Although some environmental agents have been linked to certain amyloid diseases, the molecular basis of their action remains unclear. Environmental stresses trigger amyloid formation and loss, acting either via influencing intracellular concentrations of the amyloidogenic proteins or via heterologous inducers of prions. Studies of environmental and physiological regulation of yeast prions open new possibilities for pharmacological intervention and/or prophylactic procedures aiming on common cellular systems rather than the properties of specific amyloids.
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16
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Manjrekar J, Shah H. Protein-based inheritance. Semin Cell Dev Biol 2019; 97:138-155. [PMID: 31344459 DOI: 10.1016/j.semcdb.2019.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 07/08/2019] [Indexed: 01/17/2023]
Abstract
Epigenetic mechanisms of inheritance have come to occupy a prominent place in our understanding of living systems, primarily eukaryotes. There has been considerable and lively discussion of the possible evolutionary significance of transgenerational epigenetic inheritance. One particular type of epigenetic inheritance that has not figured much in general discussions is that based on conformational changes in proteins, where proteins with altered conformations can act as templates to propagate their own structure. An increasing number of such proteins - prions and prion-like - are being discovered. Phenotypes due to the structurally altered proteins are transmitted along with their structures. This review discusses the properties and implications of "classical" amyloid-forming prions, as well as the broader class of proteins with intrinsically disordered domains, which are proving to have fascinating properties that appear to play important roles in cell organisation and function, especially during stress responses.
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Affiliation(s)
- Johannes Manjrekar
- Microbiology Department and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, 390002, India.
| | - Hiral Shah
- Microbiology Department and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, 390002, India
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17
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Howie RL, Jay-Garcia LM, Kiktev DA, Faber QL, Murphy M, Rees KA, Sachwani N, Chernoff YO. Role of the Cell Asymmetry Apparatus and Ribosome-Associated Chaperones in the Destabilization of a Saccharomyces cerevisiae Prion by Heat Shock. Genetics 2019; 212:757-771. [PMID: 31142614 PMCID: PMC6614889 DOI: 10.1534/genetics.119.302237] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/10/2019] [Indexed: 11/18/2022] Open
Abstract
Self-perpetuating transmissible protein aggregates, termed prions, are implicated in mammalian diseases and control phenotypically detectable traits in Saccharomyces cerevisiae Yeast stress-inducible chaperone proteins, including Hsp104 and Hsp70-Ssa that counteract cytotoxic protein aggregation, also control prion propagation. Stress-damaged proteins that are not disaggregated by chaperones are cleared from daughter cells via mother-specific asymmetric segregation in cell divisions following heat shock. Short-term mild heat stress destabilizes [PSI+ ], a prion isoform of the yeast translation termination factor Sup35 This destabilization is linked to the induction of the Hsp104 chaperone. Here, we show that the region of Hsp104 known to be required for curing by artificially overproduced Hsp104 is also required for heat-shock-mediated [PSI+ ] destabilization. Moreover, deletion of the SIR2 gene, coding for a deacetylase crucial for asymmetric segregation of heat-damaged proteins, also counteracts heat-shock-mediated destabilization of [PSI+ ], and Sup35 aggregates are colocalized with aggregates of heat-damaged proteins marked by Hsp104-GFP. These results support the role of asymmetric segregation in prion destabilization. Finally, we show that depletion of the heat-shock noninducible ribosome-associated chaperone Hsp70-Ssb decreases heat-shock-mediated destabilization of [PSI+ ], while disruption of a cochaperone complex mediating the binding of Hsp70-Ssb to the ribosome increases prion loss. Our data indicate that Hsp70-Ssb relocates from the ribosome to the cytosol during heat stress. Cytosolic Hsp70-Ssb has been shown to antagonize the function of Hsp70-Ssa in prion propagation, which explains the Hsp70-Ssb effect on prion destabilization by heat shock. This result uncovers the stress-related role of a stress noninducible chaperone.
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Affiliation(s)
- Rebecca L Howie
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | | | - Denis A Kiktev
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
- Laboratory of Amyloid Biology, St. Petersburg State University, Russia 199034
| | - Quincy L Faber
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Margaret Murphy
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Katherine A Rees
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Numera Sachwani
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Yury O Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
- Laboratory of Amyloid Biology, St. Petersburg State University, Russia 199034
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18
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Three J-proteins impact Hsp104-mediated variant-specific prion elimination: a new critical role for a low-complexity domain. Curr Genet 2019; 66:51-58. [PMID: 31230108 PMCID: PMC6925661 DOI: 10.1007/s00294-019-01006-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022]
Abstract
Prions are self-propagating protein isoforms that are typically amyloid. In Saccharomyces cerevisiae, amyloid prion aggregates are fragmented by a trio involving three classes of chaperone proteins: Hsp40s, also known as J-proteins, Hsp70s, and Hsp104. Hsp104, the sole Hsp100-class disaggregase in yeast, along with the Hsp70 Ssa and the J-protein Sis1, is required for the propagation of all known amyloid yeast prions. However, when Hsp104 is ectopically overexpressed, only the prion [PSI+] is efficiently eliminated from cell populations via a highly debated mechanism that also requires Sis1. Recently, we reported roles for two additional J-proteins, Apj1 and Ydj1, in this process. Deletion of Apj1, a J-protein involved in the degradation of sumoylated proteins, partially blocks Hsp104-mediated [PSI+] elimination. Apj1 and Sis1 were found to have overlapping functions, as overexpression of one compensates for loss of function of the other. In addition, overexpression of Ydj1, the most abundant J-protein in the yeast cytosol, completely blocks Hsp104-mediated curing. Yeast prions exhibit structural polymorphisms known as “variants”; most intriguingly, these J-protein effects were only observed for strong variants, suggesting variant-specific mechanisms. Here, we review these results and present new data resolving the domains of Apj1 responsible, specifically implicating the involvement of Apj1’s Q/S-rich low-complexity domain.
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19
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Yeast Sup35 Prion Structure: Two Types, Four Parts, Many Variants. Int J Mol Sci 2019; 20:ijms20112633. [PMID: 31146333 PMCID: PMC6600473 DOI: 10.3390/ijms20112633] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 12/14/2022] Open
Abstract
The yeast [PSI+] prion, formed by the Sup35 (eRF3) protein, has multiple structural variants differing in the strength of nonsense suppressor phenotype. Structure of [PSI+] and its variation are characterized poorly. Here, we mapped Sup35 amyloid cores of 26 [PSI+] ex vivo prions of different origin using proteinase K digestion and mass spectrometric identification of resistant peptides. In all [PSI+] variants the Sup35 amino acid residues 2-32 were fully resistant and the region up to residue 72 was partially resistant. Proteinase K-resistant structures were also found within regions 73-124, 125-153, and 154-221, but their presence differed between [PSI+] isolates. Two distinct digestion patterns were observed for region 2-72, which always correlated with the "strong" and "weak" [PSI+] nonsense suppressor phenotypes. Also, all [PSI+] with a weak pattern were eliminated by multicopy HSP104 gene and were not toxic when combined with multicopy SUP35. [PSI+] with a strong pattern showed opposite properties, being resistant to multicopy HSP104 and lethal with multicopy SUP35. Thus, Sup35 prion cores can be composed of up to four elements. [PSI+] variants can be divided into two classes reliably distinguishable basing on structure of the first element and the described assays.
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20
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Killian AN, Miller SC, Hines JK. Impact of Amyloid Polymorphism on Prion-Chaperone Interactions in Yeast. Viruses 2019; 11:v11040349. [PMID: 30995727 PMCID: PMC6521183 DOI: 10.3390/v11040349] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/12/2019] [Accepted: 04/14/2019] [Indexed: 12/22/2022] Open
Abstract
Yeast prions are protein-based genetic elements found in the baker's yeast Saccharomyces cerevisiae, most of which are amyloid aggregates that propagate by fragmentation and spreading of small, self-templating pieces called propagons. Fragmentation is carried out by molecular chaperones, specifically Hsp104, Hsp70, and Hsp40. Like other amyloid-forming proteins, amyloid-based yeast prions exhibit structural polymorphisms, termed "strains" in mammalian systems and "variants" in yeast, which demonstrate diverse phenotypes and chaperone requirements for propagation. Here, the known differential interactions between chaperone proteins and yeast prion variants are reviewed, specifically those of the yeast prions [PSI+], [RNQ+]/[PIN+], and [URE3]. For these prions, differences in variant-chaperone interactions (where known) with Hsp104, Hsp70s, Hsp40s, Sse1, and Hsp90 are summarized, as well as some interactions with chaperones of other species expressed in yeast. As amyloid structural differences greatly impact chaperone interactions, understanding and accounting for these variations may be crucial to the study of chaperones and both prion and non-prion amyloids.
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Affiliation(s)
- Andrea N Killian
- Department of Chemistry, Lafayette College, Easton, PA 18042, USA.
| | - Sarah C Miller
- Department of Chemistry, Lafayette College, Easton, PA 18042, USA.
| | - Justin K Hines
- Department of Chemistry, Lafayette College, Easton, PA 18042, USA.
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21
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Wickner RB, Son M, Edskes HK. Prion Variants of Yeast are Numerous, Mutable, and Segregate on Growth, Affecting Prion Pathogenesis, Transmission Barriers, and Sensitivity to Anti-Prion Systems. Viruses 2019; 11:v11030238. [PMID: 30857327 PMCID: PMC6466074 DOI: 10.3390/v11030238] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 02/07/2023] Open
Abstract
The known amyloid-based prions of Saccharomyces cerevisiae each have multiple heritable forms, called "prion variants" or "prion strains". These variants, all based on the same prion protein sequence, differ in their biological properties and their detailed amyloid structures, although each of the few examined to date have an in-register parallel folded β sheet architecture. Here, we review the range of biological properties of yeast prion variants, factors affecting their generation and propagation, the interaction of prion variants with each other, the mutability of prions, and their segregation during mitotic growth. After early differentiation between strong and weak stable and unstable variants, the parameters distinguishing the variants has dramatically increased, only occasionally correlating with the strong/weak paradigm. A sensitivity to inter- and intraspecies barriers, anti-prion systems, and chaperone deficiencies or excesses and other factors all have dramatic selective effects on prion variants. Recent studies of anti-prion systems, which cure prions in wild strains, have revealed an enormous array of new variants, normally eliminated as they arise and so not previously studied. This work suggests that defects in the anti-prion systems, analogous to immune deficiencies, may be at the root of some human amyloidoses.
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Affiliation(s)
- Reed B Wickner
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA.
| | - Moonil Son
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA.
| | - Herman K Edskes
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA.
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Yu CI, King CY. Forms and abundance of chaperone proteins influence yeast prion variant competition. Mol Microbiol 2019; 111:798-810. [PMID: 30582872 DOI: 10.1111/mmi.14192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2018] [Indexed: 02/01/2023]
Abstract
[PSI+ ] variants are different infectious conformations of the same Sup35 protein. We show that when [PSI+ ] variants VK and VL co-infect a dividing host, only one prevails in the end and the host genetic background is involved in winner selection. In the 5V-H19 background, the VK variant dominates over the VL variant. The order of dominance is reversed in the 74-D694 background, where VL can coexists with VK for a short period, but will eventually take over. Differential interaction of chaperone proteins with distinct prion variant conformations can influence the outcome of competition. Expanding the Glycine/Methionine-rich domain of Sis1, an Hsp40 protein, helps the propagation of VL. Over-expression of the Hsp70 protein Ssa2 lowers the number of prion particles (propagons) in the cell. There is more reduction for VK than VL, causing the latter to dominate in some of the 5V-H19 and all of the 74-D694 cells tested. Consistently, depleting Ssa1 in 74-D694 strengthens VK. Swapping chromosomal alleles of SSA1/2 and SIS1 between 5V-H19 and 74-D694, including cognate promoters, is not sufficient to change the native dominance order of each background, suggesting there exist additional polymorphic factors that modulate [PSI+ ] competition.
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Affiliation(s)
- Chang-I Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Chih-Yen King
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
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