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Son M, Han S, Lee S. Prions in Microbes: The Least in the Most. J Microbiol 2023; 61:881-889. [PMID: 37668956 DOI: 10.1007/s12275-023-00070-4] [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: 06/29/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 09/06/2023]
Abstract
Prions are infectious proteins that mostly replicate in self-propagating amyloid conformations (filamentous protein polymers) and consist of structurally altered normal soluble proteins. Prions can arise spontaneously in the cell without any clear reason and are generally considered fatal disease-causing agents that are only present in mammals. However, after the seminal discovery of two prions, [PSI+] and [URE3], in the eukaryotic model microorganism Saccharomyces cerevisiae, at least ten more prions have been discovered, and their biological and pathological effects on the host, molecular structure, and the relationship between prions and cellular components have been studied. In a filamentous fungus model, Podospora anserina, a vegetative incomparability-related [Het-s] prion that directly triggers cell death during anastomosis (hyphal fusion) was discovered. These prions in eukaryotic microbes have extended our understanding to overcome most fatal human prion/amyloid diseases. A prokaryotic microorganism (Clostridium botulinum) was reported to have a prion analog. The transcriptional regulators of C. botulinum-Rho can be converted into the self-replicating prion form ([RHO-X-C+]), which may affect global transcription. Here, we outline the major issues with prions in microbes and the lessons learned from the relatively uncovered microbial prion world.
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Affiliation(s)
- Moonil Son
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea.
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea.
- Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea.
| | - Sia Han
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Seyeon Lee
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea
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Edskes HK, Stroobant EE, DeWilde MP, Bezsonov EE, Wickner RB. Proteasome Control of [URE3] Prion Propagation by Degradation of Anti-Prion Proteins Cur1 and Btn2 in Saccharomyces cerevisiae. Genetics 2021; 218:6179111. [PMID: 33742650 DOI: 10.1093/genetics/iyab037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/27/2021] [Indexed: 01/16/2023] Open
Abstract
[URE3] is a prion of the nitrogen catabolism controller, Ure2p, and [PSI+] is a prion of the translation termination factor Sup35p in S. cerevisiae. Btn2p cures [URE3] by sequestration of Ure2p amyloid filaments. Cur1p, paralogous to Btn2p, also cures [URE3], but by a different (unknown) mechanism. We find that an array of mutations impairing proteasome assembly or MG132 inhibition of proteasome activity result in loss of [URE3]. In proportion to their prion-curing effects, each mutation affecting proteasomes elevates the cellular concentration of the anti-prion proteins Btn2 and Cur1. Of >4,600 proteins detected by SILAC, Btn2p was easily the most overexpressed in a pre9Δ (α3 core subunit) strain. Indeed, deletion of BTN2 and CUR1 prevents the prion-curing effects of proteasome impairment. Surprisingly, the 15 most unstable yeast proteins are not increased in pre9Δ cells suggesting altered proteasome specificity rather than simple inactivation. Hsp42, a chaperone that cooperates with Btn2 and Cur1 in curing [URE3], is also necessary for the curing produced by proteasome defects, although Hsp42p levels are not substantially altered by a proteasome defect. We find that pre9Δ and proteasome chaperone mutants that most efficiently lose [URE3], do not destabilize [PSI+] or alter cellular levels of Sup35p. A tof2 mutation or deletion likewise destabilizes [URE3], and elevates Btn2p, suggesting that Tof2p deficiency inactivates proteasomes. We suggest that when proteasomes are saturated with denatured/misfolded proteins, their reduced degradation of Btn2p and Cur1p automatically upregulates these aggregate-handling systems to assist in the clean-up.
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Affiliation(s)
- 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
| | - Emily E Stroobant
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Morgan P DeWilde
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Evgeny E Bezsonov
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - 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
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Lauwers E, Lalli G, Brandner S, Collinge J, Compernolle V, Duyckaerts C, Edgren G, Haïk S, Hardy J, Helmy A, Ivinson AJ, Jaunmuktane Z, Jucker M, Knight R, Lemmens R, Lin IC, Love S, Mead S, Perry VH, Pickett J, Poppy G, Radford SE, Rousseau F, Routledge C, Schiavo G, Schymkowitz J, Selkoe DJ, Smith C, Thal DR, Theys T, Tiberghien P, van den Burg P, Vandekerckhove P, Walton C, Zaaijer HL, Zetterberg H, De Strooper B. Potential human transmission of amyloid β pathology: surveillance and risks. Lancet Neurol 2020; 19:872-878. [PMID: 32949547 DOI: 10.1016/s1474-4422(20)30238-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/22/2020] [Accepted: 05/28/2020] [Indexed: 01/05/2023]
Abstract
Studies in experimental animals show transmissibility of amyloidogenic proteins associated with prion diseases, Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases. Although these data raise potential concerns for public health, convincing evidence for human iatrogenic transmission only exists for prions and amyloid β after systemic injections of contaminated growth hormone extracts or dura mater grafts derived from cadavers. Even though these procedures are now obsolete, some reports raise the possibility of iatrogenic transmission of amyloid β through putatively contaminated neurosurgical equipment. Iatrogenic transmission of amyloid β might lead to amyloid deposition in the brain parenchyma and blood vessel walls, potentially resulting in cerebral amyloid angiopathy after several decades. Cerebral amyloid angiopathy can cause life-threatening brain haemorrhages; yet, there is no proof that the transmission of amyloid β can also lead to Alzheimer's dementia. Large, long-term epidemiological studies and sensitive, cost-efficient tools to detect amyloid are needed to better understand any potential routes of amyloid β transmission and to clarify whether other similar proteopathic seeds, such as tau or α-synuclein, can also be transferred iatrogenically.
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Affiliation(s)
- Elsa Lauwers
- VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium; Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Giovanna Lalli
- UK Dementia Research Institute, University College London, London, UK
| | - Sebastian Brandner
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK; Division of Neuropathology, National Hospital for Neurology and Neurosurgery, University College London National Health Service Foundation Trust, London, UK
| | - John Collinge
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - Veerle Compernolle
- Blood Services, Belgian Red Cross-Flanders, Mechelen, Belgium; Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Charles Duyckaerts
- Institut du Cerveau et de la Moelle épinière, Sorbonne University, INSERM, CNRS UMR, Paris, France; Laboratoire de Neuropathologie Raymond Escourolle, Hôpital de la Pitié-Salpêtrière, Assistance Publique- Hôpitaux de Paris, Paris, France
| | - Gustaf Edgren
- Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Department of Cardiology, Södersjukhuset, Stockholm, Sweden
| | - Stéphane Haïk
- Institut du Cerveau et de la Moelle épinière, Sorbonne University, INSERM, CNRS UMR, Paris, France; Laboratoire de Neuropathologie Raymond Escourolle, Hôpital de la Pitié-Salpêtrière, Assistance Publique- Hôpitaux de Paris, Paris, France; Cellule Nationale de Référence des maladies de Creutzfeldt-Jakob, Hôpital de la Pitié-Salpêtrière, Assistance Publique- Hôpitaux de Paris, Paris, France
| | - John Hardy
- UK Dementia Research Institute, University College London, London, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK; Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London, UK; National Institute for Health Research University College London Hospitals Biomedical Research Centre, London, UK; Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong Special Administrative Region, China
| | - Adel Helmy
- Department of Clinical Neuroscience, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Adrian J Ivinson
- UK Dementia Research Institute, University College London, London, UK
| | - Zane Jaunmuktane
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Queen Square Brain Bank for Neurological Disorders, Queen Square Institute of Neurology, University College London, London, UK; Division of Neuropathology, National Hospital for Neurology and Neurosurgery, University College London National Health Service Foundation Trust, London, UK
| | - Mathias Jucker
- Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Richard Knight
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK; UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK; National Creutzfeldt-Jakob Disease Research and Surveillance Unit, Western General Hospital, Edinburgh, UK
| | - Robin Lemmens
- VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium; Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium; Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - I-Chun Lin
- UK Dementia Research Institute, University College London, London, UK
| | - Seth Love
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Simon Mead
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, UK
| | - V Hugh Perry
- UK Dementia Research Institute, University College London, London, UK
| | - James Pickett
- Alzheimer's Society, London, London, UK; Epilepsy Research UK, London, UK
| | - Guy Poppy
- Biological Sciences, University of Southampton, Southampton, UK
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Frederic Rousseau
- VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | | | - Giampietro Schiavo
- UK Dementia Research Institute, University College London, London, UK; Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Joost Schymkowitz
- VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Harvard University, Boston, MA, USA
| | - Colin Smith
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Dietmar R Thal
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium; Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Tom Theys
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
| | - Pierre Tiberghien
- Etablissement Français du Sang, La Plaine St Denis, France; Unité Mixte de Recherche, INSERM, Université de Franche-Comté, Besançon, France
| | - Peter van den Burg
- European Blood Alliance, Brussels, Belgium; Department of Transfusion Medicine, Sanquin, Amsterdam, Netherlands
| | - Philippe Vandekerckhove
- Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium; Blood Services, Belgian Red Cross-Flanders, Mechelen, Belgium
| | - Clare Walton
- Alzheimer's Society, London, London, UK; Multiple Sclerosis International Federation, London, UK
| | - Hans L Zaaijer
- Department of Blood-borne Infections, Sanquin, Amsterdam, Netherlands
| | - Henrik Zetterberg
- UK Dementia Research Institute, University College London, London, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK; Department of Psychiatry and Neurochemistry, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bart De Strooper
- VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium; Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium; UK Dementia Research Institute, University College London, London, UK.
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Kabani M, Melki R. The Yarrowia lipolytica orthologs of Sup35p assemble into thioflavin T-negative amyloid fibrils. Biochem Biophys Res Commun 2020; 529:533-539. [PMID: 32736670 DOI: 10.1016/j.bbrc.2020.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 11/26/2022]
Abstract
The translation terminator Sup35p assembles into self-replicating fibrillar aggregates that are responsible for the [PSI+] prion state. The Q/N-rich N-terminal domain together with the highly charged middle-domain (NM domain) drive the assembly of Sup35p into amyloid fibrils in vitro. NM domains are highly divergent among yeasts. The ability to convert to a prion form is however conserved among Sup35 orthologs. In particular, the Yarrowia lipolytica Sup35p stands out with an exceptionally high prion conversion rate. In the present work, we show that different Yarrowia lipolytica strains contain one of two Sup35p orthologs that differ by the number of repeats within their NM domain. The Y. lipolytica Sup35 proteins are able to assemble into amyloid fibrils. Contrary to S. cerevisiae Sup35p, fibrils made of full-length or NM domains of Y. lipolytica Sup35 proteins did not bind Thioflavin-T, a well-known marker of amyloid aggregates.
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Affiliation(s)
- Mehdi Kabani
- Institut de Biologie François Jacob, Molecular Imaging Research Center (MIRCen), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Laboratoire des Maladies Neurodégénératives, Centre National de la Recherche Scientifique (CNRS), F-92265, Fontenay-aux-Roses, France.
| | - Ronald Melki
- Institut de Biologie François Jacob, Molecular Imaging Research Center (MIRCen), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Laboratoire des Maladies Neurodégénératives, Centre National de la Recherche Scientifique (CNRS), F-92265, Fontenay-aux-Roses, France
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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: 1.8] [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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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: 3.2] [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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Kthiri A, Hidouri S, Wiem T, Jeridi R, Sheehan D, Landouls A. Biochemical and biomolecular effects induced by a static magnetic field in Saccharomyces cerevisiae: Evidence for oxidative stress. PLoS One 2019; 14:e0209843. [PMID: 30608963 PMCID: PMC6319737 DOI: 10.1371/journal.pone.0209843] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 12/12/2018] [Indexed: 01/12/2023] Open
Abstract
Exposure to static magnetic fields (SMF) can cause changes in microorganism metabolism altering key subcellular functions. The purpose of this study was to investigate whether an applied SMF could induce biological effects on growth of Saccharomyces cerevisiae, and then to probe biochemical and bio-molecular responses. We found a decrease in growth and viability under SMF (250mT) after 6h with a significant decrease in colony forming units followed by an increase between 6 h and 9 h. Moreover, measurements of antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase) demonstrated a particular profile suggesting oxidative stress. For instance, SOD and catalase activities increased in magnetized cultures after 9 h compared with unexposed samples. However, SMF exposure caused a decrease in glutathione peroxidase activity. Finally, SMF caused an increase in MDA levels as well as the content of protein carbonyl groups after 6 and 9 h of exposure.
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Affiliation(s)
- Ameni Kthiri
- Laboratory of Biochemistry and Molecular Biology, Carthage University, Faculty of Sciences of Bizerte, Zarzouna, Bizerte, Tunisia
- Environmental Research Institute and School of Biochemistry and Cell Biology, University College Cork, Western Gateway Building, Western Road, Cork, Ireland
| | - Slah Hidouri
- Laboratory of Biochemistry and Molecular Biology, Carthage University, Faculty of Sciences of Bizerte, Zarzouna, Bizerte, Tunisia
| | - Tahri Wiem
- Laboratory of Biochemistry and Molecular Biology, Carthage University, Faculty of Sciences of Bizerte, Zarzouna, Bizerte, Tunisia
| | - Roua Jeridi
- Laboratory of Biochemistry and Molecular Biology, Carthage University, Faculty of Sciences of Bizerte, Zarzouna, Bizerte, Tunisia
| | - David Sheehan
- Environmental Research Institute and School of Biochemistry and Cell Biology, University College Cork, Western Gateway Building, Western Road, Cork, Ireland
- Dept of Chemistry, College of Arts and Sciences, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
- * E-mail:
| | - Ahmed Landouls
- Laboratory of Biochemistry and Molecular Biology, Carthage University, Faculty of Sciences of Bizerte, Zarzouna, Bizerte, Tunisia
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Tuite MF. Yeast models of neurodegenerative diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 168:351-379. [DOI: 10.1016/bs.pmbts.2019.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Wickner RB, Edskes HK, Son M, Bezsonov EE, DeWilde M, Ducatez M. Yeast Prions Compared to Functional Prions and Amyloids. J Mol Biol 2018; 430:3707-3719. [PMID: 29698650 DOI: 10.1016/j.jmb.2018.04.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 01/25/2023]
Abstract
Saccharomyces cerevisiae is an occasional host to an array of prions, most based on self-propagating, self-templating amyloid filaments of a normally soluble protein. [URE3] is a prion of Ure2p, a regulator of nitrogen catabolism, while [PSI+] is a prion of Sup35p, a subunit of the translation termination factor Sup35p. In contrast to the functional prions, [Het-s] of Podospora anserina and [BETA] of yeast, the amyloid-based yeast prions are rare in wild strains, arise sporadically, have an array of prion variants for a single prion protein sequence, have a folded in-register parallel β-sheet amyloid architecture, are detrimental to their hosts, arouse a stress response in the host, and are subject to curing by various host anti-prion systems. These characteristics allow a logical basis for distinction between functional amyloids/prions and prion diseases. These infectious yeast amyloidoses are outstanding models for the many common human amyloid-based diseases that are increasingly found to have some infectious characteristics.
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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 20892-0830, MD, USA.
| | - Herman K Edskes
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Moonil Son
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Evgeny E Bezsonov
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Morgan DeWilde
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Mathieu Ducatez
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
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10
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Son M, Wickner RB. Nonsense-mediated mRNA decay factors cure most [PSI+] prion variants. Proc Natl Acad Sci U S A 2018; 115:E1184-E1193. [PMID: 29358398 PMCID: PMC5819436 DOI: 10.1073/pnas.1717495115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The yeast prion [PSI+] is a self-propagating amyloid of Sup35p with a folded in-register parallel β-sheet architecture. In a genetic screen for antiprion genes, using the yeast knockout collection, UPF1/NAM7 and UPF3, encoding nonsense-mediated mRNA decay (NMD) factors, were frequently detected. Almost all [PSI+] variants arising in the absence of Upf proteins were eliminated by restored normal levels of these proteins, and [PSI+] arises more frequently in upf mutants. Upf1p, complexed with Upf2p and Upf3p, is a multifunctional protein with helicase, ATP-binding, and RNA-binding activities promoting efficient translation termination and degradation of mRNAs with premature nonsense codons. We find that the curing ability of Upf proteins is uncorrelated with these previously reported functions but does depend on their interaction with Sup35p and formation of the Upf1p-Upf2p-Upf3p complex (i.e., the Upf complex). Indeed, Sup35p amyloid formation in vitro is inhibited by substoichiometric Upf1p. Inhibition of [PSI+] prion generation and propagation by Upf proteins may be due to the monomeric Upf proteins and the Upf complex competing with Sup35p amyloid fibers for available Sup35p monomers. Alternatively, the association of the Upf complex with amyloid filaments may block the addition of new monomers. Our results suggest that maintenance of normal protein-protein interactions prevents prion formation and can even reverse the process.
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Affiliation(s)
- Moonil Son
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Reed B Wickner
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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11
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Armiento A, Moireau P, Martin D, Lepejova N, Doumic M, Rezaei H. The mechanism of monomer transfer between two structurally distinct PrP oligomers. PLoS One 2017; 12:e0180538. [PMID: 28746342 PMCID: PMC5528842 DOI: 10.1371/journal.pone.0180538] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/01/2017] [Indexed: 12/02/2022] Open
Abstract
In mammals, Prion pathology refers to a class of infectious neuropathologies whose mechanism is based on the self-perpetuation of structural information stored in the pathological conformer. The characterisation of the PrP folding landscape has revealed the existence of a plethora of pathways conducing to the formation of structurally different assemblies with different biological properties. However, the biochemical interconnection between these diverse assemblies remains unclear. The PrP oligomerisation process leads to the formation of neurotoxic and soluble assemblies called O1 oligomers with a high size heterodispersity. By combining the measurements in time of size distribution and average size with kinetic models and data assimilation, we revealed the existence of at least two structurally distinct sets of assemblies, termed Oa and Ob, forming O1 assemblies. We propose a kinetic model representing the main processes in prion aggregation pathway: polymerisation, depolymerisation, and disintegration. The two groups interact by exchanging monomers through a disintegration process that increases the size of Oa. Our observations suggest that PrP oligomers constitute a highly dynamic population.
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Affiliation(s)
- Aurora Armiento
- Univ Paris Diderot, Sorbonne Paris Cité, Lab. J.L. Lions UMR CNRS 7598, Inria, Paris, France
| | - Philippe Moireau
- Inria and Université Paris-Saclay, Campus de l’Ecole Polytechnique, 91128 Palaiseau, France
- * E-mail: (PM); (MD); (HR)
| | - Davy Martin
- INRA, UR892, Virologie Immunologie Moléculaires, 78350 Jouy-en-Josas, France
| | - Nad’a Lepejova
- INRA, UR892, Virologie Immunologie Moléculaires, 78350 Jouy-en-Josas, France
| | - Marie Doumic
- Sorbonne Universités, Inria, UPMC Univ Paris 06, Lab. J.L. Lions UMR CNRS 7598, Paris, France
- Wolfgang Pauli Institute, University of Vienna, Oskar-Morgenstern Platz 1, 1090 Wien, Austria
- * E-mail: (PM); (MD); (HR)
| | - Human Rezaei
- INRA, UR892, Virologie Immunologie Moléculaires, 78350 Jouy-en-Josas, France
- * E-mail: (PM); (MD); (HR)
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12
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Urakov VN, Mitkevich OV, Safenkova IV, Ter‐Avanesyan MD. Ribosome‐bound Pub1 modulates stop codon decoding during translation termination in yeast. FEBS J 2017; 284:1914-1930. [DOI: 10.1111/febs.14099] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/16/2017] [Accepted: 04/28/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Valery N. Urakov
- Federal Research Center ‘Fundamentals of Biotechnology’ of the Russian Academy of Sciences Bach Institute of Biochemistry Moscow Russia
| | - Olga V. Mitkevich
- Federal Research Center ‘Fundamentals of Biotechnology’ of the Russian Academy of Sciences Bach Institute of Biochemistry Moscow Russia
| | - Irina V. Safenkova
- Federal Research Center ‘Fundamentals of Biotechnology’ of the Russian Academy of Sciences Bach Institute of Biochemistry Moscow Russia
| | - Michael D. Ter‐Avanesyan
- Federal Research Center ‘Fundamentals of Biotechnology’ of the Russian Academy of Sciences Bach Institute of Biochemistry Moscow Russia
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13
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Distinct Prion Domain Sequences Ensure Efficient Amyloid Propagation by Promoting Chaperone Binding or Processing In Vivo. PLoS Genet 2016; 12:e1006417. [PMID: 27814358 PMCID: PMC5096688 DOI: 10.1371/journal.pgen.1006417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/10/2016] [Indexed: 11/19/2022] Open
Abstract
Prions are a group of proteins that can adopt a spectrum of metastable conformations in vivo. These alternative states change protein function and are self-replicating and transmissible, creating protein-based elements of inheritance and infectivity. Prion conformational flexibility is encoded in the amino acid composition and sequence of the protein, which dictate its ability not only to form an ordered aggregate known as amyloid but also to maintain and transmit this structure in vivo. But, while we can effectively predict amyloid propensity in vitro, the mechanism by which sequence elements promote prion propagation in vivo remains unclear. In yeast, propagation of the [PSI+] prion, the amyloid form of the Sup35 protein, has been linked to an oligopeptide repeat region of the protein. Here, we demonstrate that this region is composed of separable functional elements, the repeats themselves and a repeat proximal region, which are both required for efficient prion propagation. Changes in the numbers of these elements do not alter the physical properties of Sup35 amyloid, but their presence promotes amyloid fragmentation, and therefore maintenance, by molecular chaperones. Rather than acting redundantly, our observations suggest that these sequence elements make complementary contributions to prion propagation, with the repeat proximal region promoting chaperone binding to and the repeats promoting chaperone processing of Sup35 amyloid. Protein misfolding and assembly into ordered aggregates known as amyloid has emerged as a novel mechanism for regulation of protein function. In the case of prion proteins, the resulting amyloid is transmissible, creating protein-based elements of infectivity and inheritance. These unusual properties are linked to the amino acid composition and sequence of the protein, which confer both conformational flexibility and persistence in vivo, the latter of which occurs through mechanisms that are currently poorly understood. Here, we address this open question by studying a region of the yeast prion Sup35 that has been genetically linked to persistence. We find that this region is composed of two separable elements that are both required for efficient persistence of the amyloid. These elements do not contribute to amyloid stability. Rather, they promote distinct aspects of its functional interactions with molecular chaperones, which are required for efficient conformational self-replication and transmission.
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14
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Abstract
Yeast and fungal prions are infectious proteins, most being self-propagating amyloids of normally soluble proteins. Their effects range from a very mild detriment to lethal, with specific effects dependent on the prion protein and the specific prion variant ("prion strain"). The prion amyloids of Sup35p, Ure2p, and Rnq1p are in-register, parallel, folded β-sheets, an architecture that naturally suggests a mechanism by which a protein can template its conformation, just as DNA or RNA templates its sequence. Prion propagation is critically affected by an array of chaperone systems, most notably the Hsp104/Hsp70/Hsp40 combination, which is responsible for generating new prion seeds from old filaments. The Btn2/Cur1 antiprion system cures most [URE3] prions that develop, and the Ssb antiprion system blocks [PSI+] generation.
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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, Maryland 20892-0830
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15
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Drozdova PB, Tarasov OV, Matveenko AG, Radchenko EA, Sopova JV, Polev DE, Inge-Vechtomov SG, Dobrynin PV. Genome Sequencing and Comparative Analysis of Saccharomyces cerevisiae Strains of the Peterhof Genetic Collection. PLoS One 2016; 11:e0154722. [PMID: 27152522 PMCID: PMC4859572 DOI: 10.1371/journal.pone.0154722] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/18/2016] [Indexed: 01/09/2023] Open
Abstract
The Peterhof genetic collection of Saccharomyces cerevisiae strains (PGC) is a large laboratory stock that has accumulated several thousands of strains for over than half a century. It originated independently of other common laboratory stocks from a distillery lineage (race XII). Several PGC strains have been extensively used in certain fields of yeast research but their genomes have not been thoroughly explored yet. Here we employed whole genome sequencing to characterize five selected PGC strains including one of the closest to the progenitor, 15V-P4, and several strains that have been used to study translation termination and prions in yeast (25-25-2V-P3982, 1B-D1606, 74-D694, and 6P-33G-D373). The genetic distance between the PGC progenitor and S288C is comparable to that between two geographically isolated populations. The PGC seems to be closer to two bakery strains than to S288C-related laboratory stocks or European wine strains. In genomes of the PGC strains, we found several loci which are absent from the S288C genome; 15V-P4 harbors a rare combination of the gene cluster characteristic for wine strains and the RTM1 cluster. We closely examined known and previously uncharacterized gene variants of particular strains and were able to establish the molecular basis for known phenotypes including phenylalanine auxotrophy, clumping behavior and galactose utilization. Finally, we made sequencing data and results of the analysis available for the yeast community. Our data widen the knowledge about genetic variation between Saccharomyces cerevisiae strains and can form the basis for planning future work in PGC-related strains and with PGC-derived alleles.
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Affiliation(s)
- Polina B. Drozdova
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- Bioinformatics Institute, St. Petersburg, Russia
| | - Oleg V. Tarasov
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Scientific Center of RAS, St. Petersburg, Russia
| | - Andrew G. Matveenko
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
- Laboratory of Amyloid Biology, Saint Petersburg State University, St. Petersburg, Russia
| | - Elina A. Radchenko
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- Bioinformatics Institute, St. Petersburg, Russia
| | - Julia V. Sopova
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg, Russia
| | - Dmitrii E. Polev
- Research Resource Center for Molecular and Cell Technologies, Research Park, Saint-Petersburg State University, St. Petersburg, Russia
| | - Sergey G. Inge-Vechtomov
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Pavel V. Dobrynin
- Bioinformatics Institute, St. Petersburg, Russia
- Theodosius Dobzhansky Center for Genome Bioinformatics, Saint Petersburg State University, St. Petersburg, Russia
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16
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Abstract
Although prions were first discovered through their link to severe brain degenerative diseases in animals, the emergence of prions as regulators of the phenotype of the yeast Saccharomyces cerevisiae and the filamentous fungus Podospora anserina has revealed a new facet of prion biology. In most cases, fungal prions are carried without apparent detriment to the host cell, representing a novel form of epigenetic inheritance. This raises the question of whether or not yeast prions are beneficial survival factors or actually gives rise to a "disease state" that is selected against in nature. To date, most studies on the impact of fungal prions have focused on laboratory-cultivated "domesticated" strains of S. cerevisiae. At least eight prions have now been described in this species, each with the potential to impact on a wide range of cellular processes. The discovery of prions in nondomesticated strains of S. cerevisiae and P. anserina has confirmed that prions are not simply an artifact of "domestication" of this species. In this review, I describe what we currently know about the phenotypic impact of fungal prions. I then describe how the interplay between host genotype and the prion-mediated changes can generate a wide array of phenotypic diversity. How such prion-generated diversity may be of benefit to the host in survival in a fluctuating, often hazardous environment is then outlined. Prion research has now entered a new phase in which we must now consider their biological function and evolutionary significance in the natural world.
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Affiliation(s)
- Mick F Tuite
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom.
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17
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An L, Fitzpatrick D, Harrison PM. Emergence and evolution of yeast prion and prion-like proteins. BMC Evol Biol 2016; 16:24. [PMID: 26809710 PMCID: PMC4727409 DOI: 10.1186/s12862-016-0594-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/13/2016] [Indexed: 11/10/2022] Open
Abstract
Background Prions are transmissible, propagating alternative states of proteins, and are usually made from the fibrillar, beta-sheet-rich assemblies termed amyloid. Prions in the budding yeast Saccharomyces cerevisiae propagate heritable phenotypes, uncover hidden genetic variation, function in large-scale gene regulation, and can act like diseases. Almost all these amyloid prions have asparagine/glutamine-rich (N/Q–rich) domains. Other proteins, that we term here ‘prionogenic amyloid formers’ (PAFs), have been shown to form amyloid in vivo, and to have N/Q-rich domains that can propagate heritable states in yeast cells. Also, there are >200 other S.cerevisiae proteins with prion-like N/Q-rich sequence composition. Furthermore, human proteins with such N/Q-rich composition have been linked to the pathomechanisms of neurodegenerative amyloid diseases. Results Here, we exploit the increasing abundance of complete fungal genomes to examine the ancestry of prions/PAFs and other N/Q-rich proteins across the fungal kingdom. We find distinct evolutionary behavior for Q-rich and N-rich prions/PAFs; those of ancient ancestry (outside the budding yeasts, Saccharomycetes) are Q-rich, whereas N-rich cases arose early in Saccharomycetes evolution. This emergence of N-rich prion/PAFs is linked to a large-scale emergence of N-rich proteins during Saccharomycetes evolution, with Saccharomycetes showing a distinctive trend for population sizes of prion-like proteins that sets them apart from all the other fungi. Conversely, some clades, e.g. Eurotiales, have much fewer N/Q-rich proteins, and in some cases likely lose them en masse, perhaps due to greater amyloid intolerance, although they contain relatively more non-N/Q-rich predicted prions. We find that recent mutational tendencies arising during Saccharomycetes evolution (i.e., increased numbers of N residues and a tendency to form more poly-N tracts), contributed to the expansion/development of the prion phenomenon. Variation in these mutational tendencies in Saccharomycetes is correlated with the population sizes of prion-like proteins, thus implying that selection pressures on N/Q-rich protein sequences against amyloidogenesis are not generally maintained in budding yeasts. Conclusions These results help to delineate further the limits and origins of N/Q-rich prions, and provide insight as a case study of the evolution of compositionally-defined protein domains. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0594-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lu An
- Department of Biology, McGill University, Montreal, QC, Canada
| | - David Fitzpatrick
- Bioinformatics and Molecular Evolution Unit, NUI Maynooth, Maynooth, Ireland
| | - Paul M Harrison
- Department of Biology, McGill University, Montreal, QC, Canada.
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18
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Wickner RB, Edskes HK, Gorkovskiy A, Bezsonov EE, Stroobant EE. Yeast and Fungal Prions: Amyloid-Handling Systems, Amyloid Structure, and Prion Biology. ADVANCES IN GENETICS 2016; 93:191-236. [PMID: 26915272 DOI: 10.1016/bs.adgen.2015.12.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Yeast prions (infectious proteins) were discovered by their outré genetic properties and have become important models for an array of human prion and amyloid diseases. A single prion protein can become any of many distinct amyloid forms (called prion variants or strains), each of which is self-propagating, but with different biological properties (eg, lethal vs mild). The folded in-register parallel β sheet architecture of the yeast prion amyloids naturally suggests a mechanism by which prion variant information can be faithfully transmitted for many generations. The yeast prions rely on cellular chaperones for their propagation, but can be cured by various chaperone imbalances. The Btn2/Cur1 system normally cures most variants of the [URE3] prion that arise. Although most variants of the [PSI+] and [URE3] prions are toxic or lethal, some are mild in their effects. Even the most mild forms of these prions are rare in the wild, indicating that they too are detrimental to yeast. The beneficial [Het-s] prion of Podospora anserina poses an important contrast in its structure, biology, and evolution to the yeast prions characterized thus far.
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Affiliation(s)
- R B Wickner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - H K Edskes
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - A Gorkovskiy
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - E E Bezsonov
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - E E Stroobant
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
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19
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Abstract
A prion is an infectious protein horizontally transmitting a disease or trait without a required nucleic acid. Yeast and fungal prions are nonchromosomal genes composed of protein, generally an altered form of a protein that catalyzes the same alteration of the protein. Yeast prions are thus transmitted both vertically (as genes composed of protein) and horizontally (as infectious proteins, or prions). Formation of amyloids (linear ordered β-sheet-rich protein aggregates with β-strands perpendicular to the long axis of the filament) underlies most yeast and fungal prions, and a single prion protein can have any of several distinct self-propagating amyloid forms with different biological properties (prion variants). Here we review the mechanism of faithful templating of protein conformation, the biological roles of these prions, and their interactions with cellular chaperones, the Btn2 and Cur1 aggregate-handling systems, and other cellular factors governing prion generation and propagation. Human amyloidoses include the PrP-based prion conditions and many other, more common amyloid-based diseases, several of which show prion-like features. Yeast prions increasingly are serving as models for the understanding and treatment of many mammalian amyloidoses. Patients with different clinical pictures of the same amyloidosis may be the equivalent of yeasts with different prion variants.
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20
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Zadorsky SP, Sopova YV, Andreichuk DY, Startsev VA, Medvedeva VP, Inge-Vechtomov SG. Chromosome VIII disomy influences the nonsense suppression efficiency and transition metal tolerance of the yeast Saccharomyces cerevisiae. Yeast 2015; 32:479-97. [PMID: 25874850 DOI: 10.1002/yea.3074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 02/24/2015] [Accepted: 03/27/2015] [Indexed: 01/26/2023] Open
Abstract
The SUP35 gene of the yeast Saccharomyces cerevisiae encodes the translation termination factor eRF3. Mutations in this gene lead to the suppression of nonsense mutations and a number of other pleiotropic phenotypes, one of which is impaired chromosome segregation during cell division. Similar effects result from replacing the S. cerevisiae SUP35 gene with its orthologues. A number of genetic and epigenetic changes that occur in the sup35 background result in partial compensation for this suppressor effect. In this study we showed that in S. cerevisiae strains in which the SUP35 orthologue from the yeast Pichia methanolica replaces the S. cerevisiae SUP35 gene, chromosome VIII disomy results in decreased efficiency of nonsense suppression. This antisuppressor effect is not associated with decreased stop codon read-through. We identified SBP1, a gene that localizes to chromosome VIII, as a dosage-dependent antisuppressor that strongly contributes to the overall antisuppressor effect of chromosome VIII disomy. Disomy of chromosome VIII also leads to a change in the yeast strains' tolerance of a number of transition metal salts.
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Affiliation(s)
- S P Zadorsky
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation.,St. Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, St Petersburg, Russian Federation
| | - Y V Sopova
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation.,St. Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, St Petersburg, Russian Federation
| | - D Y Andreichuk
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation
| | - V A Startsev
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation
| | - V P Medvedeva
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation
| | - S G Inge-Vechtomov
- Department of Genetics and Biotechnology, St Petersburg State University, St Petersburg, Russian Federation.,St. Petersburg Branch Vavilov Institute of General Genetics, Russian Academy of Science, St Petersburg, Russian Federation
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21
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Abstract
A prion is an infectious protein horizontally transmitting a disease or trait without a required nucleic acid. Yeast and fungal prions are nonchromosomal genes composed of protein, generally an altered form of a protein that catalyzes the same alteration of the protein. Yeast prions are thus transmitted both vertically (as genes composed of protein) and horizontally (as infectious proteins, or prions). Formation of amyloids (linear ordered β-sheet-rich protein aggregates with β-strands perpendicular to the long axis of the filament) underlies most yeast and fungal prions, and a single prion protein can have any of several distinct self-propagating amyloid forms with different biological properties (prion variants). Here we review the mechanism of faithful templating of protein conformation, the biological roles of these prions, and their interactions with cellular chaperones, the Btn2 and Cur1 aggregate-handling systems, and other cellular factors governing prion generation and propagation. Human amyloidoses include the PrP-based prion conditions and many other, more common amyloid-based diseases, several of which show prion-like features. Yeast prions increasingly are serving as models for the understanding and treatment of many mammalian amyloidoses. Patients with different clinical pictures of the same amyloidosis may be the equivalent of yeasts with different prion variants.
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22
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Abstract
Sup35p of Saccharomyces cerevisiae can form the [PSI+] prion, an infectious amyloid in which the protein is largely inactive. The part of Sup35p that forms the amyloid is the region normally involved in control of mRNA turnover. The formation of [PSI+] by Sup35p's from other yeasts has been interpreted to imply that the prion-forming ability of Sup35p is conserved in evolution, and thus of survival/fitness/evolutionary value to these organisms. We surveyed a larger number of yeast and fungal species by the same criteria as used previously and find that the Sup35p from many species cannot form prions. [PSI+] could be formed by the Sup35p from Candida albicans, Candida maltosa, Debaromyces hansenii, and Kluyveromyces lactis, but orders of magnitude less often than the S. cerevisiae Sup35p converts to the prion form. The Sup35s from Schizosaccharomyces pombe and Ashbya gossypii clearly do not form [PSI+]. We were also unable to detect [PSI+] formation by the Sup35ps from Aspergillus nidulans, Aspergillus fumigatus, Magnaporthe grisea, Ustilago maydis, or Cryptococcus neoformans. Each of two C. albicans SUP35 alleles can form [PSI+], but transmission from one to the other is partially blocked. These results suggest that the prion-forming ability of Sup35p is not a conserved trait, but is an occasional deleterious side effect of a protein domain conserved for another function.
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23
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Abstract
Prions (infectious proteins) cause fatal neurodegenerative diseases in mammals. In the yeast Saccharomyces cerevisiae, many toxic and lethal variants of the [PSI+] and [URE3] prions have been identified in laboratory strains, although some commonly studied variants do not seem to impair cell growth. Phylogenetic analysis has revealed four major clades of S. cerevisiae that share histories of two prion proteins and largely correspond to different ecological niches of yeast. The [PIN+] prion was most prevalent in commercialized niches, infrequent among wine/vineyard strains, and not observed in ancestral isolates. As previously reported, the [PSI+] and [URE3] prions are not found in any of these strains. Patterns of heterozygosity revealed genetic mosaicism and indicated extensive outcrossing among divergent strains in commercialized environments. In contrast, ancestral isolates were all homozygous and wine/vineyard strains were closely related to each other and largely homozygous. Cellular growth patterns were highly variable within and among clades, although ancestral isolates were the most efficient sporulators and domesticated strains showed greater tendencies for flocculation. [PIN+]-infected strains had a significantly higher likelihood of polyploidy, showed a higher propensity for flocculation compared to uninfected strains, and had higher sporulation efficiencies compared to domesticated, uninfected strains. Extensive phenotypic variability among strains from different environments suggests that S. cerevisiae is a niche generalist and that most wild strains are able to switch from asexual to sexual and from unicellular to multicellular growth in response to environmental conditions. Our data suggest that outbreeding and multicellular growth patterns adapted for domesticated environments are ecological risk factors for the [PIN+] prion in wild yeast.
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24
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Byers JS, Jarosz DF. Pernicious pathogens or expedient elements of inheritance: the significance of yeast prions. PLoS Pathog 2014; 10:e1003992. [PMID: 24722628 PMCID: PMC3983059 DOI: 10.1371/journal.ppat.1003992] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- James S Byers
- Departments of Chemical and Systems Biology and of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Daniel F Jarosz
- Departments of Chemical and Systems Biology and of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
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25
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Abstract
Yeast prions are infectious proteins that spread exclusively by mating. The frequency of prions in the wild therefore largely reflects the rate of spread by mating counterbalanced by prion growth slowing effects in the host. We recently showed that the frequency of outcross mating is about 1% of mitotic doublings with 23–46% of total matings being outcrosses. These findings imply that even the mildest forms of the [PSI+], [URE3] and [PIN+] prions impart > 1% growth/survival detriment on their hosts. Our estimate of outcrossing suggests that Saccharomyces cerevisiae is far more sexual than previously thought and would therefore be more responsive to the adaptive effects of natural selection compared with a strictly asexual yeast. Further, given its large effective population size, a growth/survival detriment of > 1% for yeast prions should strongly select against prion-infected strains in wild populations of Saccharomyces cerevisiae.
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Affiliation(s)
- Amy C Kelly
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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26
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Oishi K, Kurahashi H, Pack CG, Sako Y, Nakamura Y. A bipolar functionality of Q/N-rich proteins: Lsm4 amyloid causes clearance of yeast prions. Microbiologyopen 2013; 2:415-30. [PMID: 23512891 PMCID: PMC3684756 DOI: 10.1002/mbo3.83] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 02/13/2013] [Accepted: 02/19/2013] [Indexed: 12/11/2022] Open
Abstract
Prions are epigenetic modifiers that cause partially loss-of-function phenotypes of the proteins in Saccharomyces cerevisiae. The molecular chaperone network that supports prion propagation in the cell has seen a great progress in the last decade. However, the cellular machinery to activate or deactivate the prion states remains an enigma, largely due to insufficient knowledge of prion-regulating factors. Here, we report that overexpression of a [PSI+]-inducible Q/N-rich protein, Lsm4, eliminates the three major prions [PSI+], [URE3], and [RNQ+]. Subcloning analysis revealed that the Q/N-rich region of Lsm4 is responsible for the prion loss. Lsm4 formed an amyloid in vivo, which seemed to play a crucial role in the prion elimination. Fluorescence correlation spectroscopy analysis revealed that in the course of the Lsm4-driven [PSI+] elimination, the [PSI+] aggregates undergo a size increase, which ultimately results in the formation of conspicuous foci in otherwise [psi−]-like mother cells. We also found that the antiprion activity is a general property of [PSI+]-inducible factors. These data provoked a novel “unified” model that explains both prion induction and elimination by a single scheme.
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Affiliation(s)
- Keita Oishi
- Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan
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27
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Grossniklaus U, Kelly WG, Ferguson-Smith AC, Pembrey M, Lindquist S. Transgenerational epigenetic inheritance: how important is it? Nat Rev Genet 2013; 14:228-35. [PMID: 23416892 PMCID: PMC4066847 DOI: 10.1038/nrg3435] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Much attention has been given to the idea of transgenerational epigenetic inheritance, but fundamental questions remain regarding how much takes place and the impact that this might have on organisms. We asked five leading researchers in this area--working on a range of model organisms and in human disease--for their views on these topics. Their responses highlight the mixture of excitement and caution that surrounds transgenerational epigenetic inheritance and the wide gulf between species in terms of our knowledge of the mechanisms that may be involved.
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Affiliation(s)
- Ueli Grossniklaus
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland.
| | - William G. Kelly
- Biology Department, Emory University, 1510 Clifton Road NE, Atlanta, Georgia 30322, USA.
| | - Anne C. Ferguson-Smith
- Department of Physiology, Development and Neuroscience and the Centre for Trophoblast Research, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK.
| | - Marcus Pembrey
- Clinical and Molecular Genetics Unit, Institute of Child Health, University College London, London WC1N 1EH, UK; Avon Longitudinal Study of Parents and Children, School of Social and Community Medicine, Oakfield House, Oakfield Grove, University of Bristol, Bristol BS8 2BN, UK.
| | - Susan Lindquist
- Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA.
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Newby GA, Lindquist S. Blessings in disguise: biological benefits of prion-like mechanisms. Trends Cell Biol 2013; 23:251-9. [PMID: 23485338 DOI: 10.1016/j.tcb.2013.01.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/17/2013] [Accepted: 01/25/2013] [Indexed: 02/07/2023]
Abstract
Prions and amyloids are often associated with disease, but related mechanisms provide beneficial functions in nature. Prion-like mechanisms (PriLiMs) are found from bacteria to humans, where they alter the biological and physical properties of prion-like proteins. We have proposed that prions can serve as heritable bet-hedging devices for diversifying microbial phenotypes. Other, more dynamic proteinaceous complexes may be governed by similar self-templating conformational switches. Additional PriLiMs continue to be identified and many share features of self-templating protein structure (including amyloids) and dependence on chaperone proteins. Here, we discuss several PriLiMs and their functions, intending to spur discussion and collaboration on the subject of beneficial prion-like behaviors.
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Affiliation(s)
- Gregory A Newby
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Wickner RB, Edskes HK, Bateman DA, Kelly AC, Gorkovskiy A, Dayani Y, Zhou A. Amyloids and yeast prion biology. Biochemistry 2013; 52:1514-27. [PMID: 23379365 DOI: 10.1021/bi301686a] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The prions (infectious proteins) of Saccharomyces cerevisiae are proteins acting as genes, by templating their conformation from one molecule to another in analogy to DNA templating its sequence. Most yeast prions are amyloid forms of normally soluble proteins, and a single protein sequence can have any of several self-propagating forms (called prion strains or variants), analogous to the different possible alleles of a DNA gene. A central issue in prion biology is the structural basis of this conformational templating process. The in-register parallel β sheet structure found for several infectious yeast prion amyloids naturally suggests an explanation for this conformational templating. While most prions are plainly diseases, the [Het-s] prion of Podospora anserina may be a functional amyloid, with important structural implications. Yeast prions are important models for human amyloid diseases in general, particularly because new evidence is showing infectious aspects of several human amyloidoses not previously classified as prions. We also review studies of the roles of chaperones, aggregate-collecting proteins, and other cellular components using yeast that have led the way in improving the understanding of similar processes that must be operating in many 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, Maryland 20892-0830, USA.
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Abstract
Ure2p, normally a regulator of nitrogen catabolism in Saccharomyces cerevisiae, can be a prion (infectious protein) by forming a folded in-register parallel amyloid called [URE3]. Using S. cerevisiae as a test bed, we previously showed that Ure2p of Candida albicans (CaUre2p) can also form a prion, but that Ure2p of C. glabrata (CgUre2p) cannot. Here, we constructed C. glabrata strains to test whether CgUre2p can form a prion in its native environment. We find that while CaUre2p can form a [URE3] in C. glabrata, CgUre2p cannot, although the latter has a prion domain sequence more similar to that of ScUre2p than that of CaUre2p. This supports the notion that prion formation is not a conserved property of Ure2p but is a pathology arising sporadically. We find that some [URE3albicans] variants are restricted in their transmissibility to certain recipient strains. In addition, we show that the C. glabrata HO can induce switching of the C. glabrata mating type locus.
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31
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Clearance of yeast prions by misfolded multi-transmembrane proteins. Biochimie 2013; 95:1223-32. [PMID: 23384482 DOI: 10.1016/j.biochi.2013.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 01/18/2013] [Indexed: 11/20/2022]
Abstract
Accumulation of misfolded proteins in the endoplasmic reticulum (ER) induces the stress response to protect cells against toxicity by the unfolded protein response (UPR), heat shock response (HSR), and ER-associated degradation pathways. Here, we found that over-production of C-terminally truncated multi-transmembrane (MTM) mutant proteins triggers HSR, but not UPR, and clearance of yeast prions [PSI(+)] and [URE3]. One of the mutant MTM proteins, Dip5ΔC-v82, produces a disabled amino-acid permease. Fluorescence microscopy analysis revealed abnormal accumulation of Dip5ΔC-v82 in the ER. Importantly, the mutant defective in the GET pathway, which functions for ER membrane insertion of tail-anchored proteins, failed to translocate Dip5ΔC-v82 to the ER and disabled Dip5ΔC-v82-mediated prion clearance. These findings suggest that the GET pathway plays a pivotal role in quality assurance of MTM proteins, and entraps misfolded MTM proteins into ER compartments, leading to loss-of-prion through a yet undefined mechanism.
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Bateman DA, Wickner RB. The [PSI+] prion exists as a dynamic cloud of variants. PLoS Genet 2013; 9:e1003257. [PMID: 23382698 PMCID: PMC3561065 DOI: 10.1371/journal.pgen.1003257] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 12/04/2012] [Indexed: 12/29/2022] Open
Abstract
[PSI+] is an amyloid-based prion of Sup35p, a subunit of the translation termination factor. Prion “strains” or “variants” are amyloids with different conformations of a single protein sequence, conferring different phenotypes, but each relatively faithfully propagated. Wild Saccharomyces cerevisiae isolates have SUP35 alleles that fall into three groups, called reference, Δ19, and E9, with limited transmissibility of [PSI+] between cells expressing these different polymorphs. Here we show that prion transmission pattern between different Sup35 polymorphs is prion variant-dependent. Passage of one prion variant from one Sup35 polymorph to another need not change the prion variant. Surprisingly, simple mitotic growth of a [PSI+] strain results in a spectrum of variant transmission properties among the progeny clones. Even cells that have grown for >150 generations continue to vary in transmission properties, suggesting that simple variant segregation is insufficient to explain the results. Rather, there appears to be continuous generation of a cloud of prion variants, with one or another becoming stochastically dominant, only to be succeeded by a different mixture. We find that among the rare wild isolates containing [PSI+], all indistinguishably “weak” [PSI+], are several different variants based on their transmission efficiencies to other Sup35 alleles. Most show some limitation of transmission, indicating that the evolved wild Sup35 alleles are effective in limiting the spread of [PSI+]. Notably, a “strong [PSI+]” can have any of several different transmission efficiency patterns, showing that “strong” versus “weak” is insufficient to indicate prion variant uniformity. The [PSI+] prion (infectious protein) of yeast is a self-propagating amyloid (filamentous protein polymer) of the Sup35 protein, a subunit of the translation termination factor. A single protein can form many biologically distinct prions, called prion variants. Wild yeast strains have three groups of Sup35 sequences (polymorphs), which partially block transmission of the [PSI+] prion from cell to cell. We find that [PSI+] variants (including the rare [PSI+] from wild yeasts) show different transmission patterns from one Sup35 sequence to another. Moreover, we find segregation of different prion variants on mitotic growth and evidence for generation of new variants with growth under non-selective conditions. This data supports the “prion cloud” model, that prions are not uniform structures but have an array of related self-propagating amyloid structures.
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Affiliation(s)
- David A. Bateman
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Reed B. Wickner
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Solis-Escalante D, Kuijpers NGA, Bongaerts N, Bolat I, Bosman L, Pronk JT, Daran JM, Daran-Lapujade P. amdSYM, a new dominant recyclable marker cassette for Saccharomyces cerevisiae. FEMS Yeast Res 2012; 13:126-39. [PMID: 23253382 PMCID: PMC3563226 DOI: 10.1111/1567-1364.12024] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/09/2012] [Accepted: 11/09/2012] [Indexed: 12/17/2022] Open
Abstract
Despite the large collection of selectable marker genes available for Saccharomyces cerevisiae, marker availability can still present a hurdle when dozens of genetic manipulations are required. Recyclable markers, counterselectable cassettes that can be removed from the targeted genome after use, are therefore valuable assets in ambitious metabolic engineering programs. In the present work, the new recyclable dominant marker cassette amdSYM, formed by the Ashbya gossypii TEF2 promoter and terminator and a codon-optimized acetamidase gene (Aspergillus nidulans amdS), is presented. The amdSYM cassette confers S. cerevisiae the ability to use acetamide as sole nitrogen source. Direct repeats flanking the amdS gene allow for its efficient recombinative excision. As previously demonstrated in filamentous fungi, loss of the amdS marker cassette from S. cerevisiae can be rapidly selected for by growth in the presence of fluoroacetamide. The amdSYM cassette can be used in different genetic backgrounds and represents the first counterselectable dominant marker gene cassette for use in S. cerevisiae. Furthermore, using astute cassette design, amdSYM excision can be performed without leaving a scar or heterologous sequences in the targeted genome. The present work therefore demonstrates that amdSYM is a useful addition to the genetic engineering toolbox for Saccharomyces laboratory, wild, and industrial strains.
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Abstract
The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the "protein only" model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-β aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions.
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Affiliation(s)
- Susan W Liebman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada 89557, USA.
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35
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Baudin-Baillieu A, Fabret C, Namy O. Are prions part of the dark matter of the cell? Prion 2011; 5:299-304. [PMID: 22052346 DOI: 10.4161/pri.18316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The [PSI+] determinant in Saccharomyces cerevisiae is the prion protein corresponding to the eRF3 translation termination factor. Numerous infectious proteins have been described in yeast, in comparison of the unique PrP protein in higher eukaryotes. The presence of the PrP prion is associated with mammalian diseases. Whether fungal prions are beneficial or deleterious are still under discussions. The review focuses on [PSI+]-induced phenotypes and the resulting physiological consequences to shed light on the cellular changes occurring in a [PSI+] cell and its possible role in nature. To date, only two genes directly regulated at the translational level by [PSI+] have been identified. Yet, through all the published works, obtaining a consensus for the described [PSI+] phenotypes appeared a tricky task. They are highly dependent on the prion variant and the genetic background of the strain. The [PSI+] prion might generate diverse modifications not only at the translational, but also at the transcriptional levels, and the phenotypic heterogeneity is the result of these complex combinations of the genotypic expression.
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Kabani M, Melki R. Yeast prions assembly and propagation: contributions of the prion and non-prion moieties and the nature of assemblies. Prion 2011; 5:277-84. [PMID: 22052349 DOI: 10.4161/pri.18070] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Yeast prions are self-perpetuating protein aggregates that are at the origin of heritable and transmissible non-Mendelian phenotypic traits. Among these, [PSI+], [URE3] and [PIN+] are the most well documented prions and arise from the assembly of Sup35p, Ure2p and Rnq1p, respectively, into insoluble fibrillar assemblies. Fibril assembly depends on the presence of N- or C-terminal prion domains (PrDs) which are not homologous in sequence but share unusual amino-acid compositions, such as enrichment in polar residues (glutamines and asparagines) or the presence of oligopeptide repeats. Purified PrDs form amyloid fibrils that can convert prion-free cells to the prion state upon transformation. Nonetheless, isolated PrDs and full-length prion proteins have different aggregation, structural and infectious properties. In addition, mutations in the "non-prion" domains (non-PrDs) of Sup35p, Ure2p and Rnq1p were shown to affect their prion properties in vitro and in vivo. Despite these evidences, the implication of the functional non-PrDs in fibril assembly and prion propagation has been mostly overlooked. In this review, we discuss the contribution of non-PrDs to prion assemblies, and the structure-function relationship in prion infectivity in the light of recent findings on Sup35p and Ure2p assembly into infectious fibrils from our laboratory and others.
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Affiliation(s)
- Mehdi Kabani
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
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37
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Park SK, Pegan SD, Mesecar AD, Jungbauer LM, LaDu MJ, Liebman SW. Development and validation of a yeast high-throughput screen for inhibitors of Aβ₄₂ oligomerization. Dis Model Mech 2011; 4:822-31. [PMID: 21810907 PMCID: PMC3209651 DOI: 10.1242/dmm.007963] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recent reports point to small soluble oligomers, rather than insoluble fibrils, of amyloid β (Aβ), as the primary toxic species in Alzheimer’s disease. Previously, we developed a low-throughput assay in yeast that is capable of detecting small Aβ42 oligomer formation. Specifically, Aβ42 fused to the functional release factor domain of yeast translational termination factor, Sup35p, formed sodium dodecyl sulfate (SDS)-stable low-n oligomers in living yeast, which impaired release factor activity. As a result, the assay for oligomer formation uses yeast growth to indicate restored release factor activity and presumably reduced oligomer formation. We now describe our translation of this assay into a high-throughput screen (HTS) for anti-oligomeric compounds. By doing so, we also identified two presumptive anti-oligomeric compounds from a sub-library of 12,800 drug-like small molecules. Subsequent biochemical analysis confirmed their anti-oligomeric activity, suggesting that this form of HTS is an efficient, sensitive and cost-effective approach to identify new inhibitors of Aβ42 oligomerization.
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Affiliation(s)
- Sei-Kyoung Park
- Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA
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38
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Toombs JA, Liss NM, Cobble KR, Ben-Musa Z, Ross ED. [PSI+] maintenance is dependent on the composition, not primary sequence, of the oligopeptide repeat domain. PLoS One 2011; 6:e21953. [PMID: 21760933 PMCID: PMC3132755 DOI: 10.1371/journal.pone.0021953] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 06/14/2011] [Indexed: 01/29/2023] Open
Abstract
[PSI+], the prion form of the yeast Sup35 protein, results from the structural conversion of Sup35 from a soluble form into an infectious amyloid form. The infectivity of prions is thought to result from chaperone-dependent fiber cleavage that breaks large prion fibers into smaller, inheritable propagons. Like the mammalian prion protein PrP, Sup35 contains an oligopeptide repeat domain. Deletion analysis indicates that the oligopeptide repeat domain is critical for [PSI+] propagation, while a distinct region of the prion domain is responsible for prion nucleation. The PrP oligopeptide repeat domain can substitute for the Sup35 oligopeptide repeat domain in supporting [PSI+] propagation, suggesting a common role for repeats in supporting prion maintenance. However, randomizing the order of the amino acids in the Sup35 prion domain does not block prion formation or propagation, suggesting that amino acid composition is the primary determinant of Sup35's prion propensity. Thus, it is unclear what role the oligopeptide repeats play in [PSI+] propagation: the repeats could simply act as a non-specific spacer separating the prion nucleation domain from the rest of the protein; the repeats could contain specific compositional elements that promote prion propagation; or the repeats, while not essential for prion propagation, might explain some unique features of [PSI+]. Here, we test these three hypotheses and show that the ability of the Sup35 and PrP repeats to support [PSI+] propagation stems from their amino acid composition, not their primary sequences. Furthermore, we demonstrate that compositional requirements for the repeat domain are distinct from those of the nucleation domain, indicating that prion nucleation and propagation are driven by distinct compositional features.
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Affiliation(s)
- James A. Toombs
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Nathan M. Liss
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kacy R. Cobble
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Zobaida Ben-Musa
- Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Eric D. Ross
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
- Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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Marcelino-Cruz AM, Bhattacharya M, Anselmo AC, Tessier PM. Site-specific structural analysis of a yeast prion strain with species-specific seeding activity. Prion 2011; 5:208-14. [PMID: 22048721 DOI: 10.4161/pri.5.3.16694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Prion proteins misfold and aggregate into multiple infectious strain variants that possess unique abilities to overcome prion species barriers, yet the structural basis for the species-specific infectivities of prion strains is poorly understood. Therefore, we have investigated the site-specific structural properties of a promiscuous chimeric form of the yeast prion Sup35 from Saccharomyces cerevisiae and Candida albicans. The Sup35 chimera forms two strain variants, each of which selectively infect one species but not the other. Importantly, the N-terminal and middle domains of the Sup35 chimera (collectively referred to as Sup35NM) contain two prion recognition elements (one from each species) that regulate the nucleation of each strain. Mutations in either prion recognition element significantly bias nucleation of one strain conformation relative to the other. Herein, we have investigated the folding of each prion recognition element for the serine-to-arginine mutant at residue 17 of Sup35NM chimera known to promote nucleation of C. albicans strain conformation. Using cysteine-specific labeling analysis, we find that residues in the C. albicans prion recognition element are solvent-shielded, while those outside the recognition sequence (including most of those in the S. cerevisiae recognition element) are solvent-exposed. Moreover, we find that proline mutations in the C. albicans recognition sequence disrupt the prion templating activity of this strain conformation. Our structural findings reveal that differential folding of complementary and non-complementary prion recognition elements within the prion amyloid core of the Sup35NM chimera is the structural basis for its species-specific templating activity.
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Affiliation(s)
- Anna Marie Marcelino-Cruz
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
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Kurahashi H, Pack CG, Shibata S, Oishi K, Sako Y, Nakamura Y. [PSI(+)] aggregate enlargement in rnq1 nonprion domain mutants, leading to a loss of prion in yeast. Genes Cells 2011; 16:576-89. [PMID: 21453425 DOI: 10.1111/j.1365-2443.2011.01511.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
[PIN(+)] is the prion form of the Rnq1 protein of unknown function in Saccharomyces cerevisiae. A glutamine/asparagine (Q/N)-rich C-terminal domain is necessary for the propagation of [PIN(+)], whereas the N-terminal region is non-Q/N-rich and considered the nonprion domain. Here, we isolated numerous single-amino-acid mutations in Rnq1, phenotypically similar to Rnq1Δ100, which inhibit [PSI(+)] propagation in the [PIN(+)] state, but not in the [pin(-)] state, when overproduced. The dynamics of the prion aggregates was analyzed by semi-denaturing detergent-agarose gel electrophoresis and fluorescence correlation spectroscopy. The results indicated that [PSI(+)] aggregates were enlarged in mother cells and, instead, not apparently transmitted into daughter cells. Under these conditions, the activity of Hsp104, a known prion disaggregase, was not affected when monitored for the thermotolerance of the rnq1 mutants. These [PSI(+)]-inhibitory rnq1 mutations did not affect [PIN(+)] propagation itself when over-expressed from a strong promoter, but instead destabilized [PIN(+)] when expressed from the weak authentic RNQ1 promoter. The majority of these mutated residues are mapped to the surface, and on one side, of contiguous α-helices of the nonprion domain of Rnq1, suggesting its involvement in interactions with a prion or a factor necessary for prion development.
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Affiliation(s)
- Hiroshi Kurahashi
- Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Shirokanedai, Minato-ku, Japan
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41
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Bruce KL, Chernoff YO. Sequence specificity and fidelity of prion transmission in yeast. Semin Cell Dev Biol 2011; 22:444-51. [PMID: 21439395 DOI: 10.1016/j.semcdb.2011.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 03/15/2011] [Accepted: 03/15/2011] [Indexed: 11/27/2022]
Abstract
Amyloid formation is a widespread feature of various proteins. It is associated with both important diseases (including infectious mammalian prions) and biologically positive functions, and provides a basis for structural "templating" and protein-based epigenetic inheritance (for example, in the case of yeast prions). Amyloid templating is characterized by a high level of sequence specificity and conformational fidelity. Even slight variations in sequence may produce a strong barrier for prion transmission. Yeast models provide useful insight into a mechanism of amyloid specificity and fidelity. Accumulating evidence indicates that cross-species prion transmission is controlled by the identity of short sequences (specificity stretches) rather than by the overall level of sequence identity. Location of the specificity stretches determines the location and/or size of the cross-β amyloid region that controls patterns of prion variants. In some cases of cross-species prion transmission, fidelity of variant reproduction is impaired, leading to the formation of new structural variants. We propose that such a variant switch may occur due to choice of the alternatively located secondary specificity stretches, when interaction between the primary stretches is impaired due to sequence divergence.
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Affiliation(s)
- Kathryn L Bruce
- School of Biology and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, GA 30332-0230, USA
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42
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Abstract
[URE3] is a prion (infectious protein) of the Saccharomyces cerevisiae Ure2p, a regulator of nitrogen catabolism. We show that wild S. paradoxus can be infected with a [URE3] prion, supporting the use of S. cerevisiae as a prion test bed. We find that the Ure2p of Candida albicans and C. glabrata also regulate nitrogen catabolism. Conservation of amino acid sequence within the prion domain of Ure2p has been proposed as evidence that the [URE3] prion helps its host. We show that the C. albicans Ure2p, which does not conserve this sequence, can nonetheless form a [URE3] prion in S. cerevisiae, but the C. glabrata Ure2p, which does have the conserved sequence, cannot form [URE3] as judged by its performance in S. cerevisiae. These results suggest that the sequence is not conserved to preserve prion forming ability.
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43
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Gonzalez Nelson AC, Ross ED. Interactions between non-identical prion proteins. Semin Cell Dev Biol 2011; 22:437-43. [PMID: 21354317 DOI: 10.1016/j.semcdb.2011.02.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 11/24/2022]
Abstract
Prion formation involves the conversion of soluble proteins into an infectious amyloid form. This process is highly specific, with prion aggregates templating the conversion of identical proteins. However, in some cases non-identical prion proteins can interact to promote or inhibit prion formation or propagation. These interactions affect both the efficiency with which prion diseases are transmitted across species and the normal physiology of yeast prion formation and propagation. Here we examine two types of heterologous prion interactions: interactions between related proteins from different species (the species barrier) and interactions between unrelated prion proteins within a single species. Interestingly, although very subtle changes in protein sequence can significantly reduce or eliminate cross-species prion transmission, in Saccharomyces cerevisiae completely unrelated prion proteins can interact to affect prion formation and propagation.
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Affiliation(s)
- Aaron C Gonzalez Nelson
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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44
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Baudin-Baillieu A, Fabret C, Namy O. Are prions part of the dark matter of the cell? Prion 2011; 5. [PMID: 22052346 PMCID: PMC4012406 DOI: 10.4161/pri.5.4.18316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The [PSI+] determinant in Saccharomyces cerevisiae is the prion protein corresponding to the eRF3 translation termination factor. Numerous infectious proteins have been described in yeast, in comparison of the unique PrP protein in higher eukaryotes. The presence of the PrP prion is associated with mammalian diseases. Whether fungal prions are beneficial or deleterious are still under discussions. The review focuses on [PSI+]-induced phenotypes and the resulting physiological consequences to shed light on the cellular changes occurring in a [PSI+] cell and its possible role in nature. To date, only two genes directly regulated at the translational level by [PSI+] have been identified. Yet, through all the published works, obtaining a consensus for the described [PSI+] phenotypes appeared a tricky task. They are highly dependent on the prion variant and the genetic background of the strain. The [PSI+] prion might generate diverse modifications not only at the translational, but also at the transcriptional levels, and the phenotypic heterogeneity is the result of these complex combinations of the genotypic expression.
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Safadi RA, Talarek N, Jacques N, Aigle M. Yeast prions: could they be exaptations? The URE2/[URE3] system in Kluyveromyces lactis. FEMS Yeast Res 2010; 11:151-3. [DOI: 10.1111/j.1567-1364.2010.00700.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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The prion hypothesis: from biological anomaly to basic regulatory mechanism. Nat Rev Mol Cell Biol 2010; 11:823-33. [PMID: 21081963 DOI: 10.1038/nrm3007] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Prions are unusual proteinaceous infectious agents that are typically associated with a class of fatal degenerative diseases of the mammalian brain. However, the discovery of fungal prions, which are not associated with disease, suggests that we must now consider the effect of these factors on basic cellular physiology in a different light. Fungal prions are epigenetic determinants that can alter a range of cellular processes, including metabolism and gene expression pathways, and these changes can lead to a range of prion-associated phenotypes. The mechanistic similarities between prion propagation in mammals and fungi suggest that prions are not a biological anomaly but instead could be a newly appreciated and perhaps ubiquitous regulatory mechanism.
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Egami S, Naruse Y, Watarai H. Effect of static magnetic fields on the budding of yeast cells. Bioelectromagnetics 2010; 31:622-9. [DOI: 10.1002/bem.20599] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Prions, protein homeostasis, and phenotypic diversity. Trends Cell Biol 2010; 20:125-33. [PMID: 20071174 DOI: 10.1016/j.tcb.2009.12.003] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 12/05/2009] [Accepted: 12/08/2009] [Indexed: 01/14/2023]
Abstract
Prions are fascinating but often misunderstood protein aggregation phenomena. The traditional association of the mammalian prion protein with disease has overshadowed a potentially more interesting attribute of prions: their ability to create protein-based molecular memories. In fungi, prions alter the relationship between genotype and phenotype in a heritable way that diversifies clonal populations. Recent findings in yeast indicate that prions might be much more common than previously realized. Moreover, prion-driven phenotypic diversity increases under stress, and can be amplified by the dynamic maturation of prion-initiating states. In this article, we suggest that these qualities allow prions to act as 'bet-hedging' devices that facilitate the adaptation of yeasts to stressful environments, and might speed the evolution of new traits.
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Unraveling infectious structures, strain variants and species barriers for the yeast prion [PSI+]. Nat Struct Mol Biol 2009; 16:598-605. [PMID: 19491937 DOI: 10.1038/nsmb.1617] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 05/11/2009] [Indexed: 11/08/2022]
Abstract
Prions are proteins that can access multiple conformations, at least one of which is beta-sheet rich, infectious and self-perpetuating in nature. These infectious proteins show several remarkable biological activities, including the ability to form multiple infectious prion conformations, also known as strains or variants, encoding unique biological phenotypes, and to establish and overcome prion species (transmission) barriers. In this Perspective, we highlight recent studies of the yeast prion [PSI(+)], using various biochemical and structural methods, that have begun to illuminate the molecular mechanisms by which self-perpetuating prions encipher such biological activities. We also discuss several aspects of prion conformational change and structure that remain either unknown or controversial, and we propose approaches to accelerate the understanding of these enigmatic, infectious conformers.
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Abstract
The faithful and rapid translation of genetic information into peptide sequences is an indispensable property of the ribosome. The mechanistic understanding of strategies used by the ribosome to achieve both speed and fidelity during translation results from nearly a half century of biochemical and structural studies. Emerging from these studies is the common theme that the ribosome uses local as well as remote conformational switches to govern induced-fit mechanisms that ensure accuracy in codon recognition during both tRNA selection and translation termination.
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