121 results on '"Sven J. Saupe"'
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2. Mutations du mythe de l’ADN, étapes de matérialisation du gène
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Sonia Dheur and Sven J. Saupe
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materialism ,DNA ,genetic determinism ,symbol ,Social Sciences - Abstract
In the last century, biology has established DNA as the material basis of heredity. This molecule is characterized by a dual temporality as a moulding of past environments and as a mould of organisms to come. We aim to give a brief description of the history of this substance as a scientific and cultural object, to point out key events of materialization along this trajectory but also more paradoxical moments of re-idealization. Human genomics now claim a form of exhaustivity in the characterization of the genetic material, reviving the notion of genetic determinism albeit in a more complex form. Interdisciplinary approaches are required to analyse the social and political consequences of this social intrusion of genomics via private GAFA-related biotech firms or public programmes in medicine and academic sociology and psychology.
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- 2021
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3. The taxonomy of the model filamentous fungus Podospora anserina
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S. Lorena Ament-Velásquez, Hanna Johannesson, Tatiana Giraud, Robert Debuchy, Sven J. Saupe, Alfons J. M. Debets, Eric Bastiaans, Fabienne Malagnac, Pierre Grognet, Leonardo Peraza-Reyes, Pierre Gladieux, Åsa Kruys, Philippe Silar, Sabine M. Huhndorf, Andrew N. Miller, and Aaron A. Vogan
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Botany ,QK1-989 - Abstract
The filamentous fungus Podospora anserina has been used as a model organism for more than 100 years and has proved to be an invaluable resource in numerous areas of research. Throughout this period, P. anserina has been embroiled in a number of taxonomic controversies regarding the proper name under which it should be called. The most recent taxonomic treatment proposed to change the name of this important species to Triangularia anserina. The results of past name changes of this species indicate that the broader research community is unlikely to accept this change, which will lead to nomenclatural instability and confusion in literature. Here, we review the phylogeny of the species closely related to P. anserina and provide evidence that currently available marker information is insufficient to resolve the relationships amongst many of the lineages. We argue that it is not only premature to propose a new name for P. anserina based on current data, but also that every effort should be made to retain P. anserina as the current name to ensure stability and to minimise confusion in scientific literature. Therefore, we synonymise Triangularia with Podospora and suggest that either the type species of Podospora be moved to P. anserina from P. fimiseda or that all species within the Podosporaceae be placed in the genus Podospora.
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- 2020
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4. Structures of Pathological and Functional Amyloids and Prions, a Solid-State NMR Perspective
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Asen Daskalov, Nadia El Mammeri, Alons Lends, Jayakrishna Shenoy, Gaelle Lamon, Yann Fichou, Ahmad Saad, Denis Martinez, Estelle Morvan, Melanie Berbon, Axelle Grélard, Brice Kauffmann, Mathias Ferber, Benjamin Bardiaux, Birgit Habenstein, Sven J. Saupe, and Antoine Loquet
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prion structure ,amyloid fibril ,solid-state NMR ,functional amyloids ,structural biology ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Infectious proteins or prions are a remarkable class of pathogens, where pathogenicity and infectious state correspond to conformational transition of a protein fold. The conformational change translates into the formation by the protein of insoluble amyloid aggregates, associated in humans with various neurodegenerative disorders and systemic protein-deposition diseases. The prion principle, however, is not limited to pathogenicity. While pathological amyloids (and prions) emerge from protein misfolding, a class of functional amyloids has been defined, consisting of amyloid-forming domains under natural selection and with diverse biological roles. Although of great importance, prion amyloid structures remain challenging for conventional structural biology techniques. Solid-state nuclear magnetic resonance (SSNMR) has been preferentially used to investigate these insoluble, morphologically heterogeneous aggregates with poor crystallinity. SSNMR methods have yielded a wealth of knowledge regarding the fundamentals of prion biology and have helped to solve the structures of several prion and prion-like fibrils. Here, we will review pathological and functional amyloid structures and will discuss some of the obtained structural models. We will finish the review with a perspective on integrative approaches combining solid-state NMR, electron paramagnetic resonance and cryo-electron microscopy, which can complement and extend our toolkit to structurally explore various facets of prion biology.
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- 2021
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5. Partial Prion Cross-Seeding between Fungal and Mammalian Amyloid Signaling Motifs
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Thierry Bardin, Asen Daskalov, Sophie Barrouilhet, Alexandra Granger-Farbos, Bénédicte Salin, Corinne Blancard, Brice Kauffmann, Sven J. Saupe, and Virginie Coustou
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Microbiology ,QR1-502 - Abstract
Amyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell death execution proteins through a process of amyloid templating akin to prion propagation.
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- 2021
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6. Exploring a diverse world of effector domains and amyloid signaling motifs in fungal NLR proteins.
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Jakub Wojciechowski, Emirhan Tekoglu, Marlena Gasior-Glogowska, Virginie Coustou, Natalia Szulc, Monika Szefczyk, Marta Kopaczynska, Sven J. Saupe, and Witold Dyrka
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- 2022
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7. Combinations of Spok genes create multiple meiotic drivers in Podospora
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Aaron A Vogan, S Lorena Ament-Velásquez, Alexandra Granger-Farbos, Jesper Svedberg, Eric Bastiaans, Alfons JM Debets, Virginie Coustou, Hélène Yvanne, Corinne Clavé, Sven J Saupe, and Hanna Johannesson
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Podospora ,selfish genetic element ,spore killer ,genomic conflict ,fungi ,gene drive ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Meiotic drive is the preferential transmission of a particular allele during sexual reproduction. The phenomenon is observed as spore killing in multiple fungi. In natural populations of Podospora anserina, seven spore killer types (Psks) have been identified through classical genetic analyses. Here we show that the Spok gene family underlies the Psks. The combination of Spok genes at different chromosomal locations defines the spore killer types and creates a killing hierarchy within a population. We identify two novel Spok homologs located within a large (74–167 kbp) region (the Spok block) that resides in different chromosomal locations in different strains. We confirm that the SPOK protein performs both killing and resistance functions and show that these activities are dependent on distinct domains, a predicted nuclease and kinase domain. Genomic and phylogenetic analyses across ascomycetes suggest that the Spok genes disperse through cross-species transfer, and evolve by duplication and diversification within lineages.
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- 2019
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8. To self or not to self? Absence of mate choice despite costly outcrossing in the fungus Podospora anserina
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Ivain Martinossi‐Allibert, Sandra Lorena Ament‐Velásquez, Sven J. Saupe, and Hanna Johannesson
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Evolutionary Biology ,sexual reproduction ,reproductive strategy ,outcrossing ,Evolutionsbiologi ,ascomycetes ,Podospora ,selfing ,Genetics ,mating strategy ,fungi ,mate choice ,Genetik ,Ecology, Evolution, Behavior and Systematics - Abstract
Fungi have a large potential for flexibility in their mode of sexual reproduction, resulting in mating systems ranging from haploid selfing to outcrossing. However, we know little about which mating strategies are used in nature, and why, even in well-studied model organisms. Here, we explored the fitness consequences of alternative mating strategies in the ascomycete fungus Podospora anserina. We measured and compared fitness proxies of nine genotypes in either diploid selfing or outcrossing events, over two generations, and with or without environmental stress. We showed that fitness was consistently lower in outcrossing events, irrespective of the environment. The cost of outcrossing was partly attributed to non-self recognition genes with pleiotropic effects on fertility. We then predicted that when presented with options to either self or outcross, individuals would perform mate choice in favour of the reproductive strategy that yields higher fitness. Contrary to our prediction, individuals did not seem to avoid outcrossing when a choice was offered, in spite of the fitness cost incurred. Our results suggest that, although functionally diploid, P. anserina does not benefit from outcrossing in most cases. We outline different explanations for the apparent lack of mate choice in face of high fitness costs associated with outcrossing, including a new perspective on the pleiotropic effect of non-self recognition genes.
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- 2022
9. Author response for 'To self or not to self? Absence of mate choice despite costly outcrossing in the fungus Podospora anserina'
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null Ivain Martinossi‐Allibert, null Sandra Lorena Ament‐Velásquez, null Sven J. Saupe, and null Hanna Johannesson
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- 2022
10. On the Mechanistic Basis of Killer Meiotic Drive in Fungi
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Sven J. Saupe and Hanna Johannesson
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Meiosis ,Neurospora ,Genes, Fungal ,Schizosaccharomyces ,Spores, Fungal ,Microbiology - Abstract
Spore killers are specific genetic elements in fungi that kill sexual spores that do not contain them. A range of studies in the last few years have provided the long-awaited first insights into the molecular mechanistic aspects of spore killing in different fungal models, including both yeast-forming and filamentous Ascomycota. Here we describe these recent advances, focusing on the wtf system in the fission yeast Schizosaccharomyces pombe; the Sk spore killers of Neurospora species; and two spore-killer systems in Podospora anserina, Spok and [Het-s]. The spore killers appear thus far mechanistically unrelated. They can involve large genomic rearrangements but most often rely on the action of just a single gene. Data gathered so far show that the protein domains involved in the killing and resistance processes differ among the systems and are not homologous. The emerging picture sketched by these studies is thus one of great mechanistic and evolutionary diversity of elements that cheat during meiosis and are thereby preferentially inherited over sexual generations.
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- 2022
11. The expanding scope of amyloid signalling
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Sven J. Saupe and Asen Daskalov
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0301 basic medicine ,Amyloid ,Prions ,Biology ,Biochemistry ,NLR ,Fungal Proteins ,prion ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Immune system ,Regulated cell death ,Animals ,Extra-View ,RHIM ,Het-s ,Scope (project management) ,regulated cell death ,Cell Biology ,Cell biology ,030104 developmental biology ,Infectious Diseases ,Signalling ,Signalling pathways ,030217 neurology & neurosurgery ,Signal Transduction ,Article Commentary - Abstract
Formation of higher-order supramolecular complexes has emerged as a common principle underlying activity of a number of immune and regulated cell-death signalling pathways in animals, plants and fungi. Some of these signalosomes employ functional amyloid motifs in their assembly process. The description of such systems in fungi finds its origin in earlier studies on a fungal prion termed [Het-s], originally identified as a non-Mendelian cytoplasmic infectious element. Janine Beisson has been a key contributor to such early studies. Recent work on this and related systems offers a more integrated view framing this prion in a broader picture including related signalling systems described in animals. We propose here an auto-commentary centred on three recent studies on amyloid signalling in microbes. Collectively, these studies increase our understanding of fold conservation in functional amyloids and the structural basis of seeding, highlight the relation of fungal amyloid motifs to mammalian RHIM (RIP homotypic interaction motif) and expand the concept of Nod-like receptor-based amyloid signalosomes to the prokaryote reign.
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- 2021
12. Exploring a diverse world of effector domains and amyloid signaling motifs in fungal NLR proteins
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Jakub W. Wojciechowski, Emirhan Tekoglu, Marlena Gąsior-Głogowska, Virginie Coustou, Natalia Szulc, Monika Szefczyk, Marta Kopaczyńska, Sven J. Saupe, and Witold Dyrka
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Cellular and Molecular Neuroscience ,Computational Theory and Mathematics ,Ecology ,Modeling and Simulation ,Genetics ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics - Abstract
NLR proteins are intracellular receptors constituting a conserved component of the innate immune system of multicellular organisms. In fungi, NLRs are characterized by high diversity of architectures and presence of amyloid signaling. Here, we explore the diverse world of effector and signaling domains of fungal NLRs using state-of-the-art bioinformatic methods including MMseqs2 for fast clustering, probabilistic context-free grammars for sequence analysis, and AlphaFold2 deep neural networks for structure prediction. In addition to substantially improving the overall annotation, especially in basidiomycetes, the study identifies novel domains and reveals the structural similarity of MLKL-related HeLo- and Goodbye-like domains forming the most abundant superfamily of fungal NLR effectors. Moreover, compared to previous studies, we found several times more amyloid motifs, including novel families, and validated aggregating and prion-forming properties of the most abundant of them in vitro and in vivo. Also, through an extensive in silico search, the NLR-associated amyloid signaling is for the first time identified in basidiomycetes. The emerging picture highlights similarities and differences in the NLR architectures and amyloid signaling in ascomycetes, basidiomycetes and other branches of life.
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- 2022
13. Amyloid Signaling in Filamentous Fungi and Bacteria
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Sven J. Saupe
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Models, Molecular ,Amyloid ,Programmed cell death ,Prions ,Necroptosis ,NLR Proteins ,Nod ,Biology ,Microbiology ,Fungal Proteins ,03 medical and health sciences ,0302 clinical medicine ,Animals ,Receptor ,030304 developmental biology ,Mammals ,0303 health sciences ,Bacteria ,Effector ,Fungi ,Cell biology ,Multicellular organism ,Receptor-Interacting Protein Serine-Threonine Kinases ,Signal transduction ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Amyloids are implicated in many protein misfolding diseases. Amyloid folds, however, also display a range of functional roles particularly in the microbial world. The templating ability of these folds endows them with specific properties allowing their self-propagation and protein-to-protein transmission in vivo. This property, the prion principle, is exploited by specific signaling pathways that use transmission of the amyloid fold as a way to convey information from a receptor to an effector protein. I describe here amyloid signaling pathways involving fungal nucleotide binding and oligomerization domain (NOD)-like receptors that were found to control nonself recognition and programmed cell death processes. Studies on these fungal amyloid signaling motifs stem from the characterization of the fungal [Het-s] prion protein and have led to the identification in fungi but also in multicellular bacteria of several distinct families of signaling motifs, one of which is related to RHIM [receptor-interacting protein (RIP) homotypic interaction motif], an amyloid motif regulating mammalian necroptosis.
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- 2020
14. Fungal gasdermin-like proteins are controlled by proteolytic cleavage
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Corinne Clavé, Witold Dyrka, Elizabeth A. Turcotte, Alexandra Granger-Farbos, Léa Ibarlosa, Benoît Pinson, Russell E. Vance, Sven J. Saupe, and Asen Daskalov
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Fungal Proteins ,Multidisciplinary ,HEK293 Cells ,Cell Death ,Cell Survival ,Podospora ,Gene Expression Regulation, Fungal ,fungi ,Proteolysis ,Subtilisin ,Humans ,Apoptosis ,Saccharomyces cerevisiae - Abstract
Significance The recent discovery of gasdermin-like proteins in fungi have brought to light that this family of pore-forming proteins controls cell death in two of the major eukaryotic kingdoms, fungi and mammals. Yet the regulation of cytotoxicity of the fungal gasdermins and their molecular pathways remain uncharacterized. Here, we describe the regulation through proteolytic cleavage of the fungal gasdermin HET-Q1 and uncover that a majority of fungal gasdermins are genomically clustered with protease-encoding genes. Some of these genes encode proteins with caspase-related domains and/or are members of a family of immune receptors in mammals and plants. Overall, this work contributes toward our understanding of the evolution of gasdermin-dependent cell death, enlightening multiple evolutionary parallels between signaling pathways in mammals and fungi.
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- 2022
15. Allorecognition genes drive reproductive isolation in Podospora anserina
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S. Lorena Ament-Velásquez, Aaron A. Vogan, Alexandra Granger-Farbos, Eric Bastiaans, Ivain Martinossi-Allibert, Sven J. Saupe, Suzette de Groot, Martin Lascoux, Alfons J. M. Debets, Corinne Clavé, and Hanna Johannesson
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Evolutionary Biology ,Reproductive Isolation ,Ecology ,balancing selection ,Speciation ,PE&RC ,Laboratorium voor Erfelijkheidsleer ,Reproductive isolation ,heterokaryon incompatibility genes ,Fungal Proteins ,Evolutionsbiologi ,allorecognition ,Podospora ,Genetics ,selfing ,Life Science ,Laboratory of Genetics ,vegetative incompatibility ,Ecology, Evolution, Behavior and Systematics - Abstract
Allorecognition, the capacity to discriminate self from conspecific non-self, is a ubiquitous organismal feature typically governed by genes evolving under balancing selection. Here, we show that in the fungus Podospora anserina, allorecognition loci controlling vegetative incompatibility (het genes), define two reproductively isolated groups through pleiotropic effects on sexual compatibility. These two groups emerge from the antagonistic interactions of the unlinked loci het-r (encoding a NOD-like receptor) and het-v (encoding a methyltransferase and an MLKL/HeLo domain protein). Using a combination of genetic and ecological data, supported by simulations, we provide a concrete and molecularly defined example whereby the origin and coexistence of reproductively isolated groups in sympatry is driven by pleiotropic genes under balancing selection.
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- 2022
16. Fungal gasdermin-like proteins are controlled by proteolytic cleavage
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Corinne Clavé, Witold Dyrka, Pinson B, Alexandra Granger-Farbos, Asen Daskalov, and Sven J. Saupe
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Proteases ,Programmed cell death ,biology ,Effector ,Saccharomyces cerevisiae ,Signal transduction ,biology.organism_classification ,Allorecognition ,Gene ,Podospora anserina ,Cell biology - Abstract
Gasdermins are a family of pore-forming proteins controlling an inflammatory cell death reaction in the mammalian immune system. The pore-forming ability of the gasdermin proteins is released by proteolytic cleavage with the removal of their inhibitory C-terminal domain. Recently, gasdermin-like proteins have been discovered in fungi and characterized as cell death-inducing toxins in the context of conspecific non-self discrimination (allorecognition). Although functional analogies have been established between mammalian and fungal gasdermins, the molecular pathways regulating gasdermin activity in fungi remain largely unknown. Here, we characterize a gasdermin-based cell death reaction, controlled by the het-Q allorecognition genes in the filamentous fungus Podospora anserina. We show that the cytotoxic activity of the HET-Q1 gasdermin is controlled by proteolysis. HET-Q1 loses a ∼5 kDa C-terminal fragment during the cell death reaction in presence of a subtilisin-like serine protease, termed HET-Q2. Mutational analyses and successful reconstitution of the cell death reaction in a heterologous host (Saccharomyces cerevisiae) suggest that HET-Q2 directly cleaves HET-Q1 to induce cell death. By analysing the genomic landscape of het-Q1 homologs in fungi, we uncovered that the vast majority of the gasdermin genes are clustered with protease-encoding genes. These HET-Q2-like proteins carry either subtilisin-like or caspase-related proteases, which in some cases correspond to the N-terminal effector domain of NOD-like receptor proteins (NLRs). This study thus reveals the proteolytic regulation of gasdermins in fungi and establishes evolutionary parallels between fungal and mammalian gasdermin-dependent cell death pathways.SignificanceThe recent discovery of gasdermin-like proteins in fungi have brought to light that this family of pore-forming proteins controls cell death in two of the major eukaryotic kingdoms, fungi and mammals. Yet, the regulation of cytotoxicity of the fungal gasdermins and their molecular pathways remain uncharacterized. Here, we describe the regulation through proteolytic cleavage of the fungal gasdermin HET-Q1 and uncover that majority of fungal gasdermins are genomically clustered with protease-encoding genes. Some of these genes encode proteins with caspase-related domains and/or are members of a family of immune receptors in mammals and plants. Overall, this work contributes towards our understanding of the evolution of gasdermin-dependent cell death, enlightening multiple evolutionary parallels between signaling pathways in mammals and fungi.
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- 2021
17. Rational Structure‐Based Design of Fluorescent Probes for Amyloid Folds
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Silvia Campioni, Julien Orts, Dhiman Ghosh, Roland Riek, Marielle A. Wälti, and Sven J. Saupe
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Amyloid ,Amyloid beta ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Fluorescence ,Fungal Proteins ,chemistry.chemical_compound ,Amyloid disease ,Podospora ,mental disorders ,medicine ,Humans ,Amyotrophic lateral sclerosis ,Molecular Biology ,Fluorescent Dyes ,Alpha-synuclein ,Amyloid beta-Peptides ,Molecular Structure ,biology ,010405 organic chemistry ,Abeta(1–42) ,amyloid fibrils ,fluorescence probes ,HET-s ,alpha-synuclein ,Organic Chemistry ,Rational design ,medicine.disease ,Peptide Fragments ,3. Good health ,0104 chemical sciences ,Spectrometry, Fluorescence ,chemistry ,alpha-Synuclein ,biology.protein ,Molecular Medicine ,Neuroscience ,Motor neurone disease ,Protein Binding - Abstract
Amyloid fibrils are pathological hallmarks of various human diseases, including Parkinson's, Alzheimer's, amyotrophic lateral sclerosis (ALS or motor neurone disease), and prion diseases. Treatment of the amyloid diseases are hindered, among other factors, by timely detection and therefore, early detection of the amyloid fibrils would be beneficial for treatment against these disorders. Here, a small molecular fluorescent probe is reported that selectively recognize the fibrillar form of amyloid beta(1-42), α-synuclein, and HET-s(218-289) protein over their monomeric conformation. The rational design of the reporters relies on the well-known cross-β-sheet repetition motif, the key structural feature of amyloids.
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- 2019
18. Partial Prion Cross-Seeding between Fungal and Mammalian Amyloid Signaling Motifs
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Corinne Blancard, Brice Kauffmann, Thierry Bardin, Asen Daskalov, Sophie Barrouilhet, Virginie Coustou, Alexandra Granger-Farbos, Bénédicte Salin, Sven J. Saupe, Institut de biochimie et génétique cellulaires (IBGC), and Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS)
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Programmed cell death ,Amyloid ,Prions ,[SDV]Life Sciences [q-bio] ,Necroptosis ,necroptosis ,Chaetomium ,Microbiology ,Podospora anserina ,Conserved sequence ,Host-Microbe Biology ,Fungal Proteins ,prion ,03 medical and health sciences ,0302 clinical medicine ,Podospora ,Virology ,mental disorders ,Animals ,Humans ,RIP1 ,Nucleotide Motifs ,RIP3 ,RHIM ,programmed cell death ,030304 developmental biology ,Mammals ,0303 health sciences ,Innate immune system ,biology ,fungi ,biology.organism_classification ,QR1-502 ,Cell biology ,Multigene Family ,Heterologous expression ,030217 neurology & neurosurgery ,Signal Transduction ,Research Article - Abstract
Amyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell death execution proteins through a process of amyloid templating akin to prion propagation., In filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell death-inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF, have been described. An analogous system involving a distinct amyloid signaling motif, termed PP, was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP motif bears resemblance to the RIP homotypic interaction motif (RHIM) and to RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identify here a third NLR signalosome in Podospora anserina comprising a PP motif and organized as a two-gene cluster encoding an NLR and an HELL domain cell death execution protein termed HELLP. We show that the PP motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell death-inducing activity of full-length HELLP. We detect no prion cross-seeding between HET-S, HELLF, and HELLP amyloid motifs. In addition, we find that, like PP motifs, RHIMs from human RIP1 and RIP3 kinases are able to form prions in Podospora and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell death-inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionarily related cell death signaling modules.
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- 2021
19. Structural and molecular basis of cross-seeding barriers in amyloids
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Denis Martinez, Abdelmajid Noubhani, Loren B. Andreas, Guido Pintacuda, Benjamin Bardiaux, Brice Kauffmann, Asen Daskalov, Mélanie Berbon, Antoine Loquet, Joseph S. Wall, Virginie Coustou, Nadia El Mammeri, Jan Stanek, Sven J. Saupe, Birgit Habenstein, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Centre de Résonance Magnetique Nucleaire (CRMN), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Bioinformatique structurale - Structural Bioinformatics, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Institut Européen de Chimie et Biologie (IECB), Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), We acknowledge financial support from the European Research Council (ERC) under the European Unions Horizon 2020 Research and Innovation Programme (ERC-2015-CoG GA 648974 to G.P. and ERC-2015-StG GA 639020 to A.L.), IdEx Bordeaux (Chaire d’Installation to B.H., ANR-10-IDEX-03-02), the Agence Nationale de la Recherche (ANR) (ANR-14-CE09-0020-01 to A.L., ANR-13-PDOC-0017-01 to B.H. and ANR-17-CE11-0035 to S.J.S), the INCEPTION project (Programme d'investissements d'avenir/ANR-16-CONV-0005) and the CNRS (IR-RMN FR3050). J.S. and L.B.A. were supported by individual Marie Sklodowska-Curie incoming fellowships (grant agreements 661799 'COMPLEX-FAST-MAS' and 624918 'MEM-MAS'). A.D. was supported by the Nouvelle Aquitaine Regional Council., We thank the Nouvelle Aquitaine Regional Council, University of Bordeaux, and the Contrat Plan Etat-Region (CPER) CampusB Bordeaux for the acquisition of the NMR equipment. This work has benefited from the Biophysical and Structural Chemistry Platform at IECB, CNRS UMS 3033, INSERM US001., ANR-10-IDEX-0003,IDEX BORDEAUX,Initiative d'excellence de l'Université de Bordeaux(2010), ANR-14-CE09-0020,NanoSSNMR,Nanostructures biologiques et synthétiques étudiées par Résonance Magnétique Nucléaire du Solide(2014), ANR-13-PDOC-0017,SUPRAMOL,Structures d'Assemblages Supramoléculaires par RMN du Solide : le Pseudopilus du Système de Sécrétion de Type II et le Tube de Queue du Bactériophage(2013), ANR-17-CE11-0035,SFAS,Structure et fonctions de motifs amyloïdes impliqués dans la transduction du signal(2017), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), European Project: 648974,H2020,ERC-2014-CoG,P-MEM-NMR(2015), European Project: 639020,H2020,ERC-2014-STG,Weakinteract(2015), European Project: 661799,H2020,H2020-MSCA-IF-2014,COMPLEX-fastMAS-NMR(2016), European Project: 624918,EC:FP7:PEOPLE,FP7-PEOPLE-2013-IIF,MEM-MAS(2014), École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
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0301 basic medicine ,Protein Folding ,Amyloid ,Prions ,Prion strain ,Model system ,Amyloidogenic Proteins ,Computational biology ,Biology ,010402 general chemistry ,01 natural sciences ,Models, Biological ,Podospora anserina ,Fungal Proteins ,prion ,03 medical and health sciences ,Protein Aggregates ,0302 clinical medicine ,Podospora ,Amino Acid Sequence ,Prion protein ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,Conserved Sequence ,030304 developmental biology ,cross-seeding ,0303 health sciences ,Multidisciplinary ,food and beverages ,amyloid ,Biological Sciences ,biology.organism_classification ,Sequence identity ,0104 chemical sciences ,Protein Structure, Tertiary ,[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics ,Strain specificity ,nuclear magnetic resonance ,030104 developmental biology ,sequence to fold ,Sequence Alignment ,030217 neurology & neurosurgery - Abstract
Neurodegenerative disorders are frequently associated with β-sheet-rich amyloid deposits. Amyloid-forming proteins can aggregate under different structural conformations known as strains, which can exhibit a prion-like behaviour and distinct patho-phenotypes. Precise molecular determinants defining strain specificity and cross-strain interactions (cross-seeding) are currently unknown. The HET-s prion protein from the fungus Podospora anserina represents a model system to study the fundamental properties of prion amyloids. Here, we report the amyloid prion structure of HELLF, a distant homolog of the model prion HET-s. We find that these two amyloids, sharing only 17% sequence identity, have nearly identical β-solenoid folds but lack cross-seeding ability in vivo, indicating that prion specificity can differ in extremely similar amyloid folds. We engineer the HELLF sequence to explore the limits of the sequence-to-fold conservation and to pinpoint determinants of cross-seeding and prion specificity. We find that amyloid fold conservation occurs even at an exceedingly low level of identity to HET-s (5%). Next, we derive a HELLF-based sequence, termed HEC, able to breach the cross-seeding barrier in vivo between HELLF and HET-s, unveiling determinants controlling cross-seeding at residue level. These findings show that virtually identical amyloid backbone structures might not be sufficient for cross-seeding and that critical side-chain positions could determine the seeding specificity of an amyloid fold. Our work redefines the conceptual boundaries of prion strain and shed new light on key molecular features concerning an important class of pathogenic agents.
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- 2021
20. Structures of Pathological and Functional Amyloids and Prions, a Solid-State NMR Perspective
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Jayakrishna Shenoy, Yann Fichou, Denis Martinez, Nadia El Mammeri, Brice Kauffmann, Ahmad Saad, Mathias Ferber, Gaelle Lamon, Antoine Loquet, Estelle Morvan, Asen Daskalov, Alons Lends, Mélanie Berbon, Benjamin Bardiaux, Axelle Grélard, Birgit Habenstein, Sven J. Saupe, Bardiaux, Benjamin, Structure et fonctions de motifs amyloïdes impliqués dans la transduction du signal - - SFAS2017 - ANR-17-CE11-0035 - AAPG2017 - VALID, Amyloïdes fonctionnels formés par les hydrophobines du pathogène fongique Aspergillus fumigatus - - FUNHYDRO2016 - ANR-16-CE11-0020 - AAPG2016 - VALID, Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs - - INCEPTION2016 - ANR-16-CONV-0005 - CONV - VALID, Weak interactions in self-organizations studied by NMR spectroscopy in the supramolecular solid-state - Weakinteract - - H20202015-09-01 - 2020-09-01 - 639020 - VALID, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Soutien à la Recherche de l'Institut Européen de Chimie Biologique, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Européen de Chimie et de Biologie-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Bioinformatique structurale - Structural Bioinformatics, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), We acknowledge financial support from the European Research Council (ERC) under the European Unions Horizon 2020 Research and Innovation Program (ERC-2015-StG GA no. 639020 to ALo), the ANR (ANR-17-CE11-0035 to SJS and ANR-16-CE11-0020-01 to MF, GL, BB and ALo), and INCEPTION project (PIA/ANR-16-CONV-0005) to BB. AD was supported by the Nouvelle Aquitaine Regional Council. ALe was supported by the Swiss National Science Foundation for early postdoc mobility project P2EZP2_184258. This work has benefited from the facilities and expertise of the Biophysical and Structural Chemistry platform (BPCS) at IECB, CNRS UMS3033, Inserm US001, Bordeaux University., ANR-17-CE11-0035,SFAS,Structure et fonctions de motifs amyloïdes impliqués dans la transduction du signal(2017), ANR-16-CE11-0020,FUNHYDRO,Amyloïdes fonctionnels formés par les hydrophobines du pathogène fongique Aspergillus fumigatus(2016), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), European Project: 639020,H2020,ERC-2014-STG,Weakinteract(2015), École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Européen de Chimie et de Biologie-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
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Conformational change ,Amyloid ,[SDV.BBM.BP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Review ,Computational biology ,Fibril ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,amyloid fibril ,structural biology ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,[SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Chemistry ,A protein ,Pathogenicity ,[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics ,Structural biology ,Solid-state nuclear magnetic resonance ,functional amyloids ,prion structure ,solid-state NMR ,Protein folding ,030217 neurology & neurosurgery ,RC321-571 ,Neuroscience - Abstract
International audience; Infectious proteins or prions are a remarkable class of pathogens, where pathogenicity and infectious state correspond to conformational transition of a protein fold. The conformational change translates into the formation by the protein of insoluble amyloid aggregates, associated in humans with various neurodegenerative disorders and systemic protein-deposition diseases. The prion principle, however, is not limited to pathogenicity. While pathological amyloids (and prions) emerge from protein misfolding, a class of functional amyloids has been defined, consisting of amyloid-forming domains under natural selection and with diverse biological roles. Although of great importance, prion amyloid structures remain challenging for conventional structural biology techniques. Solid-state nuclear magnetic resonance (SSNMR) has been preferentially used to investigate these insoluble, morphologically heterogeneous aggregates with poor crystallinity. SSNMR methods have yielded a wealth of knowledge regarding the fundamentals of prion biology and have helped to solve the structures of several prion and prion-like fibrils. Here, we will review pathological and functional amyloid structures and will discuss some of the obtained structural models. We will finish the review with a perspective on integrative approaches combining solid-state NMR, electron paramagnetic resonance and cryo-electron microscopy, which can complement and extend our toolkit to structurally explore various facets of prion biology.
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- 2021
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21. Identification of NLR-associated amyloid signaling motifs in bacterial genomes
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Mélanie Berbon, Antoine Loquet, Witold Dyrka, Thierry Bardin, Alons Lends, Sven J. Saupe, Bénédicte Salin, Corinne Blancard, Brice Kauffmann, Virginie Coustou, Asen Daskalov, Politechnika Wroclawska [Wrocław], Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley], University of California, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Institut Européen de Chimie et Biologie (IECB), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM), Coustou, virginie, University of California [Berkeley] (UC Berkeley), University of California (UC), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
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Amyloid ,Prions ,[SDV]Life Sciences [q-bio] ,Amino Acid Motifs ,Amyloidogenic Proteins ,NLR Proteins ,Bacterial genome size ,Cyanobacteria ,Conserved sequence ,Evolution, Molecular ,03 medical and health sciences ,0302 clinical medicine ,Structural Biology ,Animals ,Amino Acid Sequence ,Molecular Biology ,Gene ,030304 developmental biology ,Genetics ,0303 health sciences ,biology ,C-terminus ,Fungi ,biology.organism_classification ,Immunity, Innate ,N-terminus ,[SDV] Life Sciences [q-bio] ,Multicellular organism ,Drosophila ,Signal transduction ,Genome, Bacterial ,030217 neurology & neurosurgery ,Bacteria ,Signal Transduction - Abstract
International audience; In filamentous fungi, amyloid signaling sequences allow Nod-like receptors (NLRs) to activate downstream cell-death inducing proteins with HeLo and HeLo-like (HELL) domains and amyloid RHIM and RHIM-related motifs control immune defense pathways in mammals and flies. Herein, we show bioinformatically that analogous amyloid signaling motifs exist in bacteria. These short motifs are found at the N-terminus of NLRs and at the C-terminus of proteins with a domain we term BELL. The corresponding NLR and BELL proteins are encoded by adjacent genes. We identify 10 families of such bacterial amyloid signaling sequences (BASS), one of which (BASS3) is homologous to RHIM and a fungal amyloid motif termed PP. BASS motifs occur nearly exclusively in bacteria forming multicellular structures (mainly in Actinobacteria and Cyanobacteria). We analyze experimentally a subset of seven of these motifs (from the most common BASS1 family and the RHIM-related BASS3 family) and find that these sequences form fibrils in vitro. Using a fungal in vivo model, we show that all tested BASS-motifs form prions and that the NLR-side motifs seed prion-formation of the corresponding BELL-side motif. We find that BASS3 motifs show partial prion cross-seeding with mammalian RHIM and fungal PP-motifs and that proline mutations on key positions of the BASS3 core motif, conserved in RHIM and PP-motifs, abolish prion formation. This work expands the paradigm of prion amyloid signaling to multicellular prokaryotes and suggests a long-term evolutionary conservation of these motifs from bacteria, to fungi and animals.
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- 2020
22. Partial prion cross-seeding between fungal and mammalian amyloid signaling motifs
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Sophie Barrouilhet, Thierry Bardin, Sven J. Saupe, Alexandra Granger-Farbos, Asen Daskalov, Bénédicte Salin, Corinne Blancard, and Virginie Coustou
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Podospora ,Innate immune system ,biology ,Kinase ,Necroptosis ,biology.organism_classification ,Functional similarity ,Podospora anserina ,Cell biology - Abstract
In filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell-death inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF have been described. An analogous system, involving a distinct amyloid signaling motif termed PP was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP-motif bears resemblance to the RHIM and RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identified here, a third NLR signalosome in Podospora anserina comprising a PP-motif and organized as a two-gene cluster encoding a NLR and a HELL-domain cell-death execution protein termed HELLP. We show that the PP-motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell-death inducing activity of full length HELLP. We detect no prion cross-seeding between HET-S, HELLF and HELLP amyloid motifs. In addition, we find that akin to PP-motifs, RHIM motifs from human RIP1 and RIP3 kinases are able to form prions in Podospora, and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell-death inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionary related cell-death signaling modules.ImportanceAmyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell-death execution proteins through a process of amyloid templating akin to prion propagation.Among these fungal amyloid signaling sequences, the PP-motif stands out because it shows similarity to RHIM, an amyloid sequence controlling necroptotic cell-death in mammals. We characterized an amyloid signaling system comprising a PP-motif in the model species Podospora anserina thus bringing to three the number of independent amyloid signaling cell death pathways described in that species. We then show that human RHIM motifs not only propagate as prions in P. anserina but also partially cross-seed with fungal PP-prions. These results indicate that in addition to show sequence similarity, PP and RHIM-motif are at least partially functionally related, supporting a model of long-term evolutionary conservation of amyloid signaling mechanisms from fungi to mammals.
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- 2020
23. On the Binding of Congo Red to Amyloid Fibrils
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Raimon Sabaté, Carles Curutchet, F. Javier Luque, Salomé Llabrés, Alba Espargaró, Sven J. Saupe, Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Department of Physical Chemistry and Institute of Biomedicine (IBUB), Faculty of Pharmacy, and University of Barcelona
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Amyloid ,Magnetic Resonance Spectroscopy ,Prions ,Polymers ,010402 general chemistry ,Molecular mechanics ,01 natural sciences ,Catalysis ,Absorbance ,Molecular dynamics ,chemistry.chemical_compound ,03 medical and health sciences ,Bathochromic shift ,mental disorders ,[CHIM]Chemical Sciences ,Density Functional Theory ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,Binding Sites ,Chemistry ,010405 organic chemistry ,Proteins ,Congo Red ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,General Medicine ,Amyloidosis ,Congo red ,0104 chemical sciences ,Polímers ,Molecular Docking Simulation ,Crystallography ,Kinetics ,Amiloïdosi ,Colorants ,Coloring matter ,Proteïnes ,Stoichiometry ,Protein Binding - Abstract
Amyloids are characterized by their capacity to bind Congo red (CR), one of the most used amyloid-specific dyes. The structural features of CR binding were unknown for years, mainly because of the lack of amyloid structures solved at high resolution. In the last few years, solid-state NMR spectroscopy enabled the determination of the structural features of amyloids, such as the HET-s prion forming domain (HET-s PFD), which also has recently been used to determine the amyloid-CR interface at atomic resolution. Herein, we combine spectroscopic data with molecular docking, molecular dynamics, and excitonic quantum/molecular mechanics calculations to examine and rationalize CR binding to amyloids. In contrast to a previous assumption on the binding mode, our results suggest that CR binding to the HET-s PFD involves a cooperative process entailing the formation of a complex with 1:1 stoichiometry. This provides a molecular basis to explain the bathochromic shift in the maximal absorbance wavelength when CR is bound to amyloids.
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- 2020
24. Identification of NLR-associated amyloid signaling motifs in filamentous bacteria
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Asen Daskalov, Thierry Bardin, Virginie Coustou, Brice Kauffmann, Antoine Loquet, Bénédicte Salin, Witold Dyrka, Corinne Blancard, Mélanie Berbon, Alons Lends, and Sven J. Saupe
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Programmed cell death ,Multicellular organism ,biology ,Streptomyces coelicolor ,biology.organism_classification ,Sequence motif ,Receptor ,Intracellular ,Bacteria ,Cell biology ,Archaea - Abstract
NLRs (Nod-like receptors) are intracellular receptors regulating immunity, symbiosis, non-self recognition and programmed cell death in animals, plants and fungi. Several fungal NLRs employ amyloid signaling motifs to activate downstream cell-death inducing proteins. Herein, we identify in Archaea and Bacteria, short sequence motifs that occur in the same genomic context as fungal amyloid signaling motifs. We identify 10 families of bacterial amyloid signaling sequences (we term BASS), one of which (BASS3) is related to mammalian RHIM and fungal PP amyloid motifs. We find that BASS motifs occur specifically in bacteria forming multicellular structures (mainly inActinobacteriaandCyanobacteria). We analyze experimentally a subset of these motifs and find that they behave as prion forming domains when expressed in a fungal model. All tested bacterial motifs also formed fibrilsin vitro.We analyze by solid-state NMR and X-ray diffraction, the amyloid state of a protein fromStreptomyces coelicolorbearing the most common BASS1 motif and find that it forms highly ordered non-polymorphic amyloid fibrils. This work expands the paradigm of amyloid signaling to prokaryotes and underlies its relation to multicellularity.
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- 2020
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25. NLR Function in Fungi as Revealed by the Study of Self/Non-self Recognition Systems
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Asen Daskalov, Witold Dyrka, and Sven J. Saupe
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Genetics ,Heterokaryon ,Architecture domain ,biology ,fungi ,Cryphonectria ,biology.organism_classification ,Gene ,Genome ,Function (biology) ,Podospora anserina ,Neurospora crassa - Abstract
Plants and animals rely on cytoplasmic immune receptors of the NLR family to cope with a variety of biotic challenges. Proteins homologous to plant and animal NLRs were identified in fungi as part of the study of a non-self recognition and programmed cell death process known as heterokaryon incompatibility. We review the role of characterized NLR-type proteins in incompatibility in the three fungal species Podospora anserina, Cryphonectria parasitica, and Neurospora crassa and describe the phylogenetic distribution, domain architecture, and variability of the NLR gene repertoires in fungal genomes. We describe a specific type of NLR-mediated signal transduction process based on amyloid templating. We review the direct and indirect evidence suggesting that in general terms NLR-like proteins might also function as immune receptors in the fungal branch as they do in plant and animal lineages and discuss these implications in terms of the evolutionary trajectory of NLR genes.
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- 2020
26. Protein folding activity of ribosomal RNA is a selective target of two unrelated antiprion drugs.
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Déborah Tribouillard-Tanvier, Suzana Dos Reis, Fabienne Gug, Cécile Voisset, Vincent Béringue, Raimon Sabate, Ema Kikovska, Nicolas Talarek, Stéphane Bach, Chenhui Huang, Nathalie Desban, Sven J Saupe, Surachai Supattapone, Jean-Yves Thuret, Stéphane Chédin, Didier Vilette, Hervé Galons, Suparna Sanyal, and Marc Blondel
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Medicine ,Science - Abstract
6-Aminophenanthridine (6AP) and Guanabenz (GA, a drug currently in use for the treatment of hypertension) were isolated as antiprion drugs using a yeast-based assay. These structurally unrelated molecules are also active against mammalian prion in several cell-based assays and in vivo in a mouse model for prion-based diseases.Here we report the identification of cellular targets of these drugs. Using affinity chromatography matrices for both drugs, we demonstrate an RNA-dependent interaction of 6AP and GA with the ribosome. These specific interactions have no effect on the peptidyl transferase activity of the ribosome or on global translation. In contrast, 6AP and GA specifically inhibit the ribosomal RNA-mediated protein folding activity of the ribosome.6AP and GA are therefore the first compounds to selectively inhibit the protein folding activity of the ribosome. They thus constitute precious tools to study the yet largely unexplored biological role of this protein folding activity.
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- 2008
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27. Le vivant comme information
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Sonia Dheur, Sven J. Saupe, Passages, Université de Bordeaux (UB)-Ministère de la Culture et de la Communication (MCC)-Université de Pau et des Pays de l'Adour (UPPA)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et génétique cellulaires (IBGC), and Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS)
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0301 basic medicine ,biologie philosophique ,03 medical and health sciences ,030104 developmental biology ,[SDV]Life Sciences [q-bio] ,arts et sciences ,réflexivité ,biobanques ,General Medicine ,[SHS]Humanities and Social Sciences - Abstract
International audience; Comme d’autres champs de la connaissance, la biologie est maintenant affaire de big data. Nous souhaitons rendre compte ici d’une analyse réflexive que nous portons, comme chercheurs en biologie, sur les changements de pratiques et les représentations qui accompagnent l’ère génomique qui tend à réduire le vivant à de l’information. Nous développons l’idée que les technologies liées au séquençage massif induisent une relation modifiée au vivant et des approches expérimentales radicalement nouvelles. Pour nous-mêmes, et au delà de leur efficacité, nous percevons ces changements comme porteurs d’une crise qui pousse à rechercher hors du champ disciplinaire strict de la biologie, des ressources réflexives, notamment au voisinage de la pratique artistique ou d’une certaine biologie philosophique.
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- 2016
28. Zuordnung der Rückgrat- und Seitenketten-Protonen in vollständig protonierten Proteinen durch Festkörper-NMR-Spektroskopie: Mikrokristalle, Sedimente und Amyloidfibrillen
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Kaspars Tars, Serena Leone, Nicholas E. Dixon, Delia Picone, Svetlana Kotelovica, Mélanie Berbon, Birgit Habenstein, Sven J. Saupe, Zhi-Qiang Xu, Andrea Bertarello, Antoine Loquet, Denis Martinez, Jan Stanek, Abdelmajid Noubhani, Diane Cala, Andrea Pica, Inara Akopjana, Kristaps Jaudzems, Loren B. Andreas, Daniela Lalli, Guido Pintacuda, Tobias Schubeis, and Nadia El Mammeri
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010405 organic chemistry ,Chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Published
- 2016
29. Combinations of Spok genes create multiple meiotic drivers in Podospora
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S. Lorena Ament-Velásquez, Corinne Clavé, Virginie Coustou, Sven J. Saupe, Eric Bastiaans, Aaron A. Vogan, Jesper Svedberg, Alfons J. M. Debets, Hanna Johannesson, Hélène Yvanne, Alexandra Granger-Farbos, Department of Organismal Biology, Uppsala University, Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Department of Product and Production development, and Chalmers University of Technology [Göteborg]
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spore killer ,QH301-705.5 ,Science ,[SDV]Life Sciences [q-bio] ,Population ,Locus (genetics) ,Laboratorium voor Erfelijkheidsleer ,Podospora anserina ,03 medical and health sciences ,0302 clinical medicine ,Podospora ,genomics ,Gene family ,selfish genetic element ,genetics ,Biology (General) ,education ,Gene ,030304 developmental biology ,Genetics ,0303 health sciences ,education.field_of_study ,[SDV.GEN]Life Sciences [q-bio]/Genetics ,Phylogenetic tree ,biology ,evolutionary biology ,Biochemistry and Molecular Biology ,biology.organism_classification ,PE&RC ,Meiotic drive ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,genomic conflict ,Medicine ,gene drive ,Laboratory of Genetics ,fungi ,030217 neurology & neurosurgery ,Biokemi och molekylärbiologi - Abstract
Meiotic drive is the preferential transmission of a particular allele at a given locus during sexual reproduction. The phenomenon is observed as spore killing in a variety of fungal lineages, includingPodospora. In natural populations ofPodospora anserina, seven spore killers (Psks) have been identified through classical genetic analyses. Here we show that theSpokgene family underlie thePskspore killers. The combination of the variousSpokgenes at different chromosomal locations defines the spore killers and creates a killing hierarchy within the same population. We identify two novelSpokhomologs that are located within a complex region (theSpokblock) that reside in different chromosomal locations in given natural strains. We confirm that the individual SPOK proteins perform both the killing and resistance functions and show that these activities are dependent on distinct domains, a nuclease and a kinase domain respectively. Genomic data and phylogenetic analysis across ascomycetes suggest that theSpokgenes disperse via cross-species transfer, and evolve by duplication and diversification within several lineages.
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- 2019
30. Author response: Combinations of Spok genes create multiple meiotic drivers in Podospora
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Eric Bastiaans, Virginie Coustou, S. Lorena Ament-Velásquez, Hélène Yvanne, Jesper Svedberg, Alfons J. M. Debets, Alexandra Granger-Farbos, Aaron A. Vogan, Sven J. Saupe, Hanna Johannesson, and Corinne Clavé
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Genetics ,Podospora ,biology ,Meiosis ,biology.organism_classification ,Gene - Published
- 2019
31. Les scores polygéniques pangénomiques comme nouvelle forme de mesure de l'humain
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Sven J. Saupe, Sonia Dheur, Passages, Université de Bordeaux (UB)-Ministère de la Culture et de la Communication (MCC)-Université de Pau et des Pays de l'Adour (UPPA)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Pau et des Pays de l'Adour (UPPA)-Ministère de la Culture et de la Communication (MCC)-Université de Bordeaux (UB)
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[SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics ,[SDV]Life Sciences [q-bio] ,General Engineering ,General Earth and Planetary Sciences ,ComputingMilieux_MISCELLANEOUS ,General Environmental Science ,[SHS]Humanities and Social Sciences - Abstract
International audience; Chez l’homme, les études d’association pangénomiques basées sur les programmes génomiques institutionnels et commerciaux permettent aujourd’hui d’identifier des polymorphismes génétiques (SNPs) associés à des traits complexes de nature psychosociale et déterminés par des centaines de gènes différents (le niveau d’instruction, l’intelligence, des traits psychotiques, névrotiques et émotionnels…). L’enjeu immédiat n’est plus l’identification du lien causal et mécanistique qui explique la contribution d’un SNP à un trait mais la construction d’outils métrologiques nouveaux désignés scores polygéniques pangénomiques. Ces scores proposent d’exprimer en une valeur numérique unique la capacité d’un génome donné à produire un trait complexe. Ces scores deviennent des outils analytiques et prédictifs censés traduire la potentialité génétique d’une personne par rapport à ces traits psychosociaux et conduisent ainsi à une biologisation statistique de « l’exception humaine ».
- Published
- 2019
32. Combinations of
- Author
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Aaron A, Vogan, S Lorena, Ament-Velásquez, Alexandra, Granger-Farbos, Jesper, Svedberg, Eric, Bastiaans, Alfons Jm, Debets, Virginie, Coustou, Hélène, Yvanne, Corinne, Clavé, Sven J, Saupe, and Hanna, Johannesson
- Subjects
Evolutionary Biology ,spore killer ,Microbial Viability ,Genes, Fungal ,Genetics and Genomics ,Spores, Fungal ,Evolution, Molecular ,Fungal Proteins ,Meiosis ,Podospora ,genomic conflict ,selfish genetic element ,gene drive ,fungi ,Other ,Research Article - Abstract
Meiotic drive is the preferential transmission of a particular allele during sexual reproduction. The phenomenon is observed as spore killing in multiple fungi. In natural populations of Podospora anserina, seven spore killer types (Psks) have been identified through classical genetic analyses. Here we show that the Spok gene family underlies the Psks. The combination of Spok genes at different chromosomal locations defines the spore killer types and creates a killing hierarchy within a population. We identify two novel Spok homologs located within a large (74–167 kbp) region (the Spok block) that resides in different chromosomal locations in different strains. We confirm that the SPOK protein performs both killing and resistance functions and show that these activities are dependent on distinct domains, a predicted nuclease and kinase domain. Genomic and phylogenetic analyses across ascomycetes suggest that the Spok genes disperse through cross-species transfer, and evolve by duplication and diversification within lineages., eLife digest In many organisms, most cells carry two versions of a given gene, one coming from the mother and the other from the father. An exception is sexual cells such as eggs, sperm, pollen or spores, which should only contain one variant of a gene. During their formation, these cells usually have an equal chance of inheriting one of the two gene versions. However, a certain class of gene variants called meiotic drivers can cheat this process and end up in more than half of the sexual cells; often, the cells that contain the drivers can kill sibling cells that do not carry these variants. This results in the selfish genetic elements spreading through populations at a higher rate, sometimes with severe consequences such as shifting the ratio of males to females. Meiotic drivers have been discovered in a wide range of organisms, from corn to mice to fruit flies and bread mold. They also exist in the fungus Podospora anserina, where they are called ‘spore killers’. Fungi are often used to study complex genetic processes, yet the identity and mode of action of spore killers in P. anserina were still unknown. Vogan, Ament-Velásquez et al. used a combination of genetic methods to identify three genes from the Spok family which are responsible for certain spores being able to kill their siblings. Two of these were previously unknown, and they could be found in different locations throughout the genome as part of a larger genetic region. Depending on the combination of Spok genes it carries, a spore can kill or be protected against other spores that contain different permutations of the genes. Copies of these genes were also shown to be present in other fungi, including species that are a threat to crops. Scientists have already started to create synthetic meiotic drivers to manipulate how certain traits are inherited within a population. This could be useful to control or eradicate pests and insects that transmit dangerous diseases. The results by Vogan, Ament-Velásquez et al. shine a light on the complex ways that natural meiotic drivers work, including how they can be shared between species; this knowledge could inform how to safely deploy synthetic drivers in the wild.
- Published
- 2019
33. ADN, métabolisme et individualité dans la biologie philosophique de Hans Jonas
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Sven J. Saupe, Sonia Dheur, Passages, Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Pau et des Pays de l'Adour (UPPA)-Ministère de la Culture et de la Communication (MCC)-Université de Bordeaux (UB), Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), and Université de Bordeaux (UB)-Ministère de la Culture et de la Communication (MCC)-Université de Pau et des Pays de l'Adour (UPPA)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SHS.HISPHILSO]Humanities and Social Sciences/History, Philosophy and Sociology of Sciences ,[SDV]Life Sciences [q-bio] ,General Engineering ,General Earth and Planetary Sciences ,ComputingMilieux_MISCELLANEOUS ,General Environmental Science ,[SHS]Humanities and Social Sciences - Abstract
International audience; Dans le phénomène de la vie, Hans Jonas introduit une ontologie de la vie organique comme l’exercice d’une liberté nécessiteuse centrée sur le métabolisme. Dans un bref appendice du troisième essai qui compose l’ouvrage, Jonas pose que l’ADN et les cellules neuronales seraient exclus du métabolisme et constitueraient ainsi des exceptions comme invariants matériels. Nous analysons ce texte pour tenter de préciser la conception jonassienne de la vie organique. Nous posons ainsi, qu’à contre-courant de cet appendice (mais en accord avec la pensée générale de Jonas), ni l’ADN, ni les neurones ne peuvent être considérés comme des invariants matériels stricts. Nous soulignons aussi la déflation, dans cet appendice, de certains aspects de la vie organique comme la croissance, le développement et surtout l’évolution au profit d’une prise en compte de l’organisme immédiat. Nous proposons qu’avec Jonas une articulation des perspectives biologiques et phénoménologiques sur les processus du vivant soit à la fois possible et féconde.
- Published
- 2019
34. NLR surveillance of essential SEC-9 SNARE proteins induces programmed cell death upon allorecognition in filamentous fungi
- Author
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Pierre Gladieux, N. Louise Glass, Jens Heller, Corinne Clavé, Sven J. Saupe, University of California [Berkeley], University of California, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Centre National de la Recherche Scientifique (CNRS), Biologie et Génétique des Interactions Plante-Parasite (UMR BGPI), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), FGSC : P01 GM068087, National Institute of General Medical Sciences : R01 GM060468, Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under US Department of Energy : DE-AC02-05CH11231, Deutsche Forschungsgemeinschaft : HE 7254/1-1, and NIH S10 Instrumentation Grants : S10RR029668, S10RR027303
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0106 biological sciences ,0301 basic medicine ,Protein domain ,Population ,Molecular Sequence Data ,Apoptosis ,NLR Proteins ,Biology ,01 natural sciences ,Podospora anserina ,Fungal Proteins ,03 medical and health sciences ,allorecognition ,Protein Domains ,Podospora ,NOD-like receptors ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Amino Acid Sequence ,Allorecognition ,education ,[SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology ,Genetics ,Fungal protein ,education.field_of_study ,Multidisciplinary ,Innate immune system ,Neurospora crassa ,fungi ,biology.organism_classification ,Tetratricopeptide ,Neurospora ,030104 developmental biology ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,PNAS Plus ,SEC-9 SNARE ,lipids (amino acids, peptides, and proteins) ,SNARE Proteins ,Sequence Alignment ,010606 plant biology & botany ,Protein Binding - Abstract
© 2018 National Academy of Sciences. All Rights Reserved. In plants and metazoans, intracellular receptors that belong to the NOD-like receptor (NLR) family are major contributors to innate immunity. Filamentous fungal genomes contain large repertoires of genes encoding for proteins with similar architecture to plant and animal NLRs with mostly unknown function. Here, we identify and molecularly characterize patatin-like phospholipase-1 (PLP-1), an NLR-like protein containing an N-terminal patatin-like phospholipase domain, a nucleotide-binding domain (NBD), and a C-terminal tetratricopeptide repeat (TPR) domain. PLP-1 guards the essential SNARE protein SEC-9; genetic differences at plp-1 and sec-9 function to trigger allorecognition and cell death in two distantly related fungal species, Neurospora crassa and Podospora anserina. Analyses of Neurospora population samples revealed that plp-1 and sec-9 alleles are highly polymorphic, segregate into discrete haplotypes, and show transspecies polymorphism. Upon fusion between cells bearing incompatible sec-9 and plp-1 alleles, allorecognition and cell death are induced, which are dependent upon physical interaction between SEC-9 and PLP-1. The central NBD and patatin-like phospholipase activity of PLP-1 are essential for allorecognition and cell death, while the TPR domain and the polymorphic SNARE domain of SEC-9 function in conferring allelic specificity. Our data indicate that fungal NLR-like proteins function similar to NLR immune receptors in plants and animals, showing that NLRs are major contributors to innate immunity in plants and animals and for allorecognition in fungi.
- Published
- 2018
35. Detection of side-chain proton resonances of fully protonated biosolids in nano-litre volumes by magic angle spinning solid-state NMR
- Author
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Manoj Kumar Pandey, Yusuke Nishiyama, Antoine Loquet, Birgit Habenstein, Mélanie Berbon, Abdelmajid Noubhani, James Tolchard, Sven J. Saupe, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et génétique cellulaires (IBGC), and Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,Amyloid ,Proton ,Prions ,Very fast MAS ,Protonation ,010402 general chemistry ,Solid-state NMR ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Amide ,Magic angle spinning ,Side chain ,Nuclear Magnetic Resonance, Biomolecular ,Amyloid fibrils ,Spectroscopy ,Proton detection ,Carbon Isotopes ,Carbon-13 ,Resonance ,[CHIM.MATE]Chemical Sciences/Material chemistry ,0104 chemical sciences ,Crystallography ,030104 developmental biology ,chemistry ,Solid-state nuclear magnetic resonance ,Protein NMR ,Protons - Abstract
We present a new solid-state NMR proton-detected three-dimensional experiment dedicated to the observation of protein proton side chain resonances in nano-liter volumes. The experiment takes advantage of very fast magic angle spinning and double quantum 13C-13C transfer to establish efficient (H)CCH correlations detected on side chain protons. Our approach is demonstrated on the HET-s prion domain in its functional amyloid fibrillar form, fully protonated, with a sample amount of less than 500 g using a MAS frequency of 70kHz. The majority of aliphatic and aromatic side chain protons (70%) are observable, in addition to Halpha resonances, in a single experiment providing a complementary approach to the established proton-detected amide-based multidimensional solid-state NMR experiments for the study and resonance assignment of biosolid samples, in particular for aromatic side chain resonances.
- Published
- 2018
36. Amyloid Prions in Fungi
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Heather L. True, Daniel F. Jarosz, and Sven J. Saupe
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0301 basic medicine ,Microbiology (medical) ,Genetics ,Fungal protein ,Amyloid ,General Immunology and Microbiology ,Ecology ,Physiology ,Prions ,animal diseases ,Fungi ,Cell Biology ,Protein aggregation ,Biology ,Yeast ,nervous system diseases ,Microbiology ,Fungal prion ,Fungal Proteins ,03 medical and health sciences ,030104 developmental biology ,Infectious Diseases - Abstract
Prions are infectious protein polymers that have been found to cause fatal diseases in mammals. Prions have also been identified in fungi (yeast and filamentous fungi), where they behave as cytoplasmic non-Mendelian genetic elements. Fungal prions correspond in most cases to fibrillary β-sheet-rich protein aggregates termed amyloids. Fungal prion models and, in particular, yeast prions were instrumental in the description of fundamental aspects of prion structure and propagation. These models established the “protein-only” nature of prions, the physical basis of strain variation, and the role of a variety of chaperones in prion propagation and amyloid aggregate handling. Yeast and fungal prions do not necessarily correspond to harmful entities but can have adaptive roles in these organisms.
- Published
- 2017
37. Identification of a novel cell death-inducing domain reveals that fungal amyloid-controlled programmed cell death is related to necroptosis
- Author
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Mélanie Berbon, Birgit Habenstein, Raimon Sabaté, Kay Hofmann, Stéphane Chaignepain, Asen Daskalov, Sven J. Saupe, Antoine Loquet, Denis Martinez, and Bénédicte Coulary-Salin
- Subjects
Models, Molecular ,0301 basic medicine ,Amyloid ,Programmed cell death ,Magnetic Resonance Spectroscopy ,Prions ,Necroptosis ,Amino Acid Motifs ,Molecular Sequence Data ,Cell ,Protein Structure, Secondary ,Fungal Proteins ,03 medical and health sciences ,0302 clinical medicine ,X-Ray Diffraction ,Podospora ,Spectroscopy, Fourier Transform Infrared ,Homologous chromosome ,medicine ,Amino Acid Sequence ,Lipase ,Receptor ,Gene ,chemistry.chemical_classification ,Multidisciplinary ,Cell Death ,Sequence Homology, Amino Acid ,biology ,Cell Membrane ,Biological Sciences ,Protein Structure, Tertiary ,Amino acid ,Luminescent Proteins ,030104 developmental biology ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,biology.protein ,030217 neurology & neurosurgery - Abstract
Recent findings have revealed the role of prion-like mechanisms in the control of host defense and programmed cell death cascades. In fungi, HET-S, a cell death-inducing protein containing a HeLo pore-forming domain, is activated through amyloid templating by a Nod-like receptor (NLR). Here we characterize the HELLP protein behaving analogously to HET-S and bearing a new type of N-terminal cell death-inducing domain termed HeLo-like (HELL) and a C-terminal regulatory amyloid motif known as PP. The gene encoding HELLP is part of a three-gene cluster also encoding a lipase (SBP) and a Nod-like receptor, both of which display the PP motif. The PP motif is similar to the RHIM amyloid motif directing formation of the RIP1/RIP3 necrosome in humans. The C-terminal region of HELLP, HELLP(215-278), encompassing the motif, allows prion propagation and assembles into amyloid fibrils, as demonstrated by X-ray diffraction and FTIR analyses. Solid-state NMR studies reveal a well-ordered local structure of the amyloid core residues and a primary sequence that is almost entirely arranged in a rigid conformation, and confirm a β-sheet structure in an assigned stretch of three amino acids. HELLP is activated by amyloid templating and displays membrane-targeting and cell death-inducing activity. HELLP targets the SBP lipase to the membrane, suggesting a synergy between HELLP and SBP in membrane dismantling. Remarkably, the HeLo-like domain of HELLP is homologous to the pore-forming domain of MLKL, the cell death-execution protein in necroptosis, revealing a transkingdom evolutionary relationship between amyloid-controlled fungal programmed cell death and mammalian necroptosis.
- Published
- 2016
38. High natural prevalence of a fungal prion
- Author
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M. Slakhorst, Alfons J. M. Debets, Henk J. P. Dalstra, Rolf F. Hoekstra, Bertha Koopmanschap, and Sven J. Saupe
- Subjects
Genetics ,Podospora ,Multidisciplinary ,biology ,Prions ,animal diseases ,Genes, Fungal ,Locus (genetics) ,Biological Sciences ,biology.organism_classification ,Balancing selection ,Virology ,Podospora anserina ,nervous system diseases ,Fungal prion ,Meiotic drive ,Allele ,Allorecognition - Abstract
Prions are infectious proteins that cause fatal diseases in mammals. Prions have also been found in fungi, but studies on their role in nature are scarce. The proposed biological function of fungal prions is debated and varies from detrimental to benign or even beneficial. [Het-s] is a prion of the fungus Podospora anserina . The het-s locus exists as two antagonistic alleles that constitute an allorecognition system: the het-s allele encoding the protein variant capable of prion formation and the het-S allele encoding a protein variant that cannot form a prion. We document here that het-s alleles, capable of prion formation, are nearly twice as frequent as het-S alleles in a natural population of 112 individuals. Then, we report a 92% prevalence of [Het-s] prion infection among the het-s isolates and find evidence of the role of the [Het-s] /het-S allorecognition system on the incidence of infection by a deleterious senescence plasmid. We explain the het-s/het-S allele ratios by the existence of two selective forces operating at different levels. We propose that during the somatic stage, the role of [Het-s]/HET-S in allorecognition leads to frequency-dependent selection for which an equilibrated frequency would be optimal. However, in the sexual cycle, the [Het-s] prion causes meiotic drive favoring the het-s allele. Our findings indicate that [Het-s] is a selected and, therefore, widespread prion whose activity as selfish genetic element is counteracted by balancing selection for allorecognition polymorphism.
- Published
- 2012
39. Two structurally similar fungal prions efficiently cross-seed in vivo but form distinct polymers when coexpressed
- Author
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Frédérique Ness, Johanna Ceschin, Corinne Clavé, Sven J. Saupe, Annick Breton, Raimon Sabaté, and Laura Benkemoun
- Subjects
Genetics ,animal structures ,biology ,Saccharomyces cerevisiae ,Fibril ,biology.organism_classification ,Microbiology ,In vitro ,Yeast ,Podospora anserina ,Cell biology ,Fungal prion ,In vivo ,Molecular Biology ,Mitosis - Abstract
HET-s is a prion protein of the filamentous fungus Podospora anserina. An orthologue of this protein, called FgHET-s has been identified in Fusarium graminearum. The region of the FgHET-s protein corresponding to the prion forming domain of HET-s, forms amyloid fibrils in vitro. These fibrils seed HET-s(218-289) fibril formation in vitro and vice versa. The amyloid fold of HET-s(218-289) and FgHET-s(218-289) are remarkably similar although they share only 38% identity. The present work corresponds to the functional characterization of the FgHET-s(218-289) region as a prion forming domain in vivo. We show that FgHET-s(218-289) is capable of prion propagation in P. anserina and is able to substitute for the HET-s PFD in the full-length HET-s protein. In accordance with the in vitro cross-seeding experiments, we detect no species barrier between P. anserina and F. graminearum PFDs. We use the yeast Saccharomyces cerevisiae as a host to compare the prion performances of the two orthologous PFDs. We find that FgHET-s(218-289) leads to higher spontaneous prion formation rates and mitotic prion stability than HET-s(218-289). Then we analysed the outcome of HET-s(218-289)/FgHET-s(218-289) coexpression. In spite of the cross-seeding ability of HET-s(218-289) and FgHET-s(218-289), in vivo, homotypic polymerization is favoured over mixed fibril formation.
- Published
- 2011
40. The [Het-s] prion of Podospora anserina and its role in heterokaryon incompatibility
- Author
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Sven J. Saupe
- Subjects
Heterokaryon ,Genetics ,Amyloid ,Podospora ,Programmed cell death ,animal structures ,biology ,Prions ,Cell Biology ,biology.organism_classification ,Podospora anserina ,Protein Structure, Tertiary ,Filamentous fungus ,Fungal Proteins ,Models, Structural ,Homologous chromosome ,Prion protein ,Sequence Alignment ,Alleles ,Developmental Biology - Abstract
[Het-s] is a prion from the filamentous fungus Podospora anserina and corresponds to a self-perpetuating amyloid aggregate of the HET-s protein. This prion protein is involved in a fungal self/non-self discrimination process termed heterokaryon incompatibility corresponding to a cell death reaction occurring upon fusion of genetically unlike strains. Two antagonistic allelic variants of this protein exist: HET-s, the prion form of which corresponds to [Het-s] and HET-S, incapable of prion formation. Fusion of a [Het-s] and HET-S strain triggers the incompatibility reaction, so that interaction of HET-S with the [Het-s] prion leads to cell death. HET-s and HET-S are highly homologous two domain proteins with a N-terminal globular domain termed HeLo and a C-terminal unstructured prion forming domain (PFD). The structure of the prion form of the HET-s PFD has been solved by solid state NMR and corresponds to a very well ordered β-solenoid fold with a triangular hydrophobic core. The ability to form this β-solenoid fold is retained in a distant homolog of HET-s from another fungal species. A model for the mechanism of [Het-s]/HET-S incompatibility has been proposed. It is believe that when interacting with the [Het-s] prion seed, the HET-S C-terminal region adopts the β-solenoid fold. This would act as a conformational switch to induce refolding and activation of the HeLo domain which then would exert its toxicity by a yet unknown mechanism.
- Published
- 2011
41. The various facets of the protein-folding activity of the ribosome
- Author
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Cécile Voisset, Sven J. Saupe, Marc Blondel, and Grellety, Marie-Lise
- Subjects
Protein Folding ,Guanabenz ,Protein subunit ,Proteins ,RNA ,General Medicine ,Biology ,Ribosomal RNA ,Applied Microbiology and Biotechnology ,Ribosome ,Phenanthridines ,Prion Diseases ,A-site ,Muscular Dystrophy, Oculopharyngeal ,Biochemistry ,RNA, Ribosomal ,Protein Biosynthesis ,Protein biosynthesis ,Molecular Medicine ,Protein folding ,[SDV.BC] Life Sciences [q-bio]/Cellular Biology ,Ribosomes ,Ribosomal DNA ,ComputingMilieux_MISCELLANEOUS ,Molecular Chaperones - Abstract
In addition to its involvement in protein synthesis, the ribosome is implicated in protein folding. Some co-translational events, such as the rhythm of protein synthesis, the passage through the exit tunnel of the ribosome, or the interaction with ribosome-associated chaperones may help protein folding. Ribosomes from prokaryotes, eukaryotes, and mitochondria have also been shown to assist the folding of denatured proteins in vitro in a translation-independent way. This intriguing protein-folding activity of the ribosome (PFAR, also termed RPFA) has been mapped to the domain V of the large rRNA of the large subunit of the ribosome. Unfolded, newly synthesized proteins catalyze the dissociation of the two ribosomal subunits in vitro, thereby promoting ribosome recycling and facilitating accessibility of domain V to these proteins, which in turn may help their folding by PFAR. The recent identification of 6AP and GA - the two first drugs that specifically inhibit PFAR without affecting protein translation - will help decipher the biological significance of PFAR in vivo. Of note, 6AP and GA were initially isolated on the basis of their activity against prion-based diseases. Recently, 6AP and GA were also shown to be active in vivo in a drosophila model for oculopharyngeal muscular dystrophy, which is another amyloid-based disease. This effect is mimicked by large deletions in the ribosomal DNA (rDNA) locus. In addition, small deletions in the rDNA locus show a synergistic effect with low doses of 6AP and GA. Hence, PFAR may be involved in various amyloid-based diseases.
- Published
- 2011
42. Fungal incompatibility: Evolutionary origin in pathogen defense?
- Author
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Mathieu Paoletti and Sven J. Saupe
- Subjects
Autoimmunity ,Ligands ,Models, Biological ,General Biochemistry, Genetics and Molecular Biology ,Podospora anserina ,Evolution, Molecular ,Fungal Proteins ,Necrosis ,Podospora ,Autophagy ,Animals ,Humans ,Allorecognition ,Gene ,Genetics ,Fungal protein ,Innate immune system ,Cell Death ,Models, Genetic ,biology ,Effector ,Genetic Variation ,Models, Theoretical ,biology.organism_classification ,Immunity, Innate ,Protein Structure, Tertiary ,NACHT domain - Abstract
In fungi, cell fusion between genetically unlike individuals triggers a cell death reaction known as the incompatibility reaction. In Podospora anserina, the genes controlling this process belong to a gene family encoding STAND proteins with an N-terminal cell death effector domain, a central NACHT domain and a C-terminal WD-repeat domain. These incompatibility genes are extremely polymorphic, subject to positive Darwinian selection and display a remarkable genetic plasticity allowing for constant diversification of the WD-repeat domain responsible for recognition of non-self. Remarkably, the architecture of these proteins is related to pathogen-recognition receptors ensuring innate immunity in plants and animals. Here, we hypothesize that these P. anserina incompatibility genes could be components of a yet-unidentified innate immune system of fungi. As already proposed in the case of plant hybrid necrosis or graft rejection in mammals, incompatibility could be a by-product of pathogen-driven divergence in host defense genes.
- Published
- 2009
43. Procedure for Identification and Characterization of Drugs Efficient Against Mammalian Prion: From a Yeast-Based Antiprion Drug Screening Assay to In Vivo Mouse Models
- Author
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Sven J. Saupe, Hervé Galons, Marc Blondel, Cécile Voisset, and Grellety, Marie-Lise
- Subjects
Microbiology (medical) ,Protein Folding ,Prions ,animal diseases ,Saccharomyces cerevisiae ,ved/biology.organism_classification_rank.species ,Drug Evaluation, Preclinical ,Mice, Transgenic ,Ribosome ,Cell Line ,Prion Diseases ,Mice ,Anti-Infective Agents ,In vivo ,Animals ,Model organism ,[SDV.BC] Life Sciences [q-bio]/Cellular Biology ,ComputingMilieux_MISCELLANEOUS ,Pharmacology ,Genetics ,biology ,ved/biology ,General Medicine ,Ribosomal RNA ,biology.organism_classification ,Yeast ,nervous system diseases ,Fungal prion ,Biochemistry ,Molecular Medicine ,Protein folding ,Ribosomes - Abstract
Prion diseases are fatal and incurable infectious neurodegenerative disorders affecting humans and other mammals. Prions are composed essentially if not solely of PrP(Sc), a misfolded form of the host-encoded PrP protein. PrP(Sc) catalyzes the transconformation of the normal endogenous PrP (PrP(C)) into more PrP(Sc). Prion replication thus corresponds to the propagation of an altered folding state of PrP. Several prion proteins have also been identified in the simple model organism Saccharomyces cerevisiae. Yeast prion-based screening assays have allowed identification of drugs active against mammalian prions, thus revealing the existence of common prion propagation mechanisms conserved from yeast to human. To identify these conserved targets, antiprion compounds isolated in yeast can be used as baits in reverse screening strategies. Once identified, these targets could in turn lead to the development of mechanism-based cell-free antiprion screening assays. A reverse screening procedure has been performed for 6AP and GA, two antiprion compounds isolated using a yeast-based assay. Protein folding activity of the large ribosomal RNA was found to be a physical and a functional target of both 6AP and GA therefore suggesting that this activity of the ribosome may constitute a novel mechanism involved in prion propagation and, as a consequence, a new screening target.
- Published
- 2009
44. On the binding of Thioflavin-T to HET-s amyloid fibrils assembled at pH 2
- Author
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Sven J. Saupe, Raimon Sabaté, and Ioan Lascu
- Subjects
Amyloid ,Polymers ,Prions ,Static Electricity ,Peptide ,macromolecular substances ,Plasma protein binding ,Fibril ,Micelle ,Protein Structure, Secondary ,Fungal Proteins ,chemistry.chemical_compound ,Podospora ,Structural Biology ,Humans ,Insulin ,Benzothiazoles ,Fluorescent Dyes ,chemistry.chemical_classification ,Fungal protein ,Chemistry ,Hydrogen-Ion Concentration ,Receptor–ligand kinetics ,Kinetics ,Thiazoles ,Crystallography ,Thioflavin ,Protein Binding - Abstract
Amyloid fibrils are ordered beta-sheet protein or peptide polymers. The benzothiazole dye Thioflavin-T (ThT) shows a strong increase in fluorescence upon binding to amyloid fibrils and has hence become the most commonly used amyloid-specific dye. In spite of this widespread use, the mechanism underlying specific binding and fluorescence enhancement upon interaction with amyloid fibrils remains largely unknown. Recent contradictory reports have proposed radically different modes of binding. We have studied the interaction of ThT with fibrils of the prion forming domain of the fungal HET-s prion protein assembled at pH 2 in order to try to gain some insight into the general mechanism of ThT-binding and fluorescence. We found that ThT does not bind to HET-s(218-289) fibrils as a micelle as previously proposed in the case of insulin fibrils. We have measured binding kinetics, affinity and stoichiometry at pH values above and below the pI of the HET-s(218-289) fibrils and found that binding is dramatically affected by pH and ionic strength. Binding is poor at acidic pH, presumably as a result of repulsive electrostatic interaction between the positively charged ThT molecule and the fibril surface. Finally, we found that ThT acquires chiral properties when it is fibril-bound. These results are discussed in relation to the different ThT-binding modes that have been proposed.
- Published
- 2008
45. Role of Hsp104 in the Propagation and Inheritance of the [Het-s] Prion
- Author
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Suzana Dos Reis, Sven J. Saupe, Laura Benkemoun, Laurent Malato, Raimon Sabaté, Grellety, Marie-Lise, Institut de biochimie et génétique cellulaires (IBGC), and Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Prions ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,Protein aggregation ,03 medical and health sciences ,0302 clinical medicine ,Meiosis ,Genes, Reporter ,Podospora ,Heat shock protein ,[SDV.BC] Life Sciences [q-bio]/Cellular Biology ,Molecular Biology ,Heat-Shock Proteins ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,Genetics ,0303 health sciences ,Mycelium ,biology ,Temperature ,Articles ,Cell Biology ,biology.organism_classification ,Yeast ,Fungal prion ,CLPB ,Gene Deletion ,030217 neurology & neurosurgery ,Bacteria - Abstract
The chaperones of the ClpB/HSP100 family play a central role in thermotolerance in bacteria, plants, and fungi by ensuring solubilization of heat-induced protein aggregates. In addition in yeast, Hsp104 was found to be required for prion propagation. Herein, we analyze the role of Podospora anserina Hsp104 (PaHsp104) in the formation and propagation of the [Het-s] prion. We show that ΔPaHsp104 strains propagate [Het-s], making [Het-s] the first native fungal prion to be propagated in the absence of Hsp104. Nevertheless, we found that [Het-s]-propagon numbers, propagation rate, and spontaneous emergence are reduced in a ΔPaHsp104 background. In addition, inactivation of PaHsp104 leads to severe meiotic instability of [Het-s] and abolishes its meiotic drive activity. Finally, we show that ΔPaHSP104 strains are less susceptible than wild type to infection by exogenous recombinant HET-s(218–289) prion amyloids. Like [URE3] and [PIN+] in yeast but unlike [PSI+], [Het-s] is not cured by constitutive PaHsp104 overexpression. The observed effects of PaHsp104 inactivation are consistent with the described role of Hsp104 in prion aggregate shearing in yeast. However, Hsp104-dependency appears less stringent in P. anserina than in yeast; presumably because in Podospora prion propagation occurs in a syncitium.
- Published
- 2007
46. Thioflavin T fluorescence anisotropy: An alternative technique for the study of amyloid aggregation
- Author
-
Raimon Sabaté and Sven J. Saupe
- Subjects
Amyloid ,Chemistry ,Biophysics ,Fibrillogenesis ,Cell Biology ,Protein aggregation ,Fibril ,Biochemistry ,Fluorescence ,Fungal Proteins ,Thiazoles ,chemistry.chemical_compound ,Crystallography ,Spectrometry, Fluorescence ,mental disorders ,Anisotropy ,Thioflavin ,Benzothiazoles ,Dimerization ,Molecular Biology ,Fluorescence anisotropy - Abstract
The process of amyloid polymerisation raises keen interest in particular because of the biomedical impact of this process. A variety of analytical methods have been developed to monitor amyloid formation. Thioflavin T (ThT) is the most commonly used dye for detection of amyloid aggregation. Nevertheless, ThT fluorescence enhancement is strongly dependent of fibril morphology. In this study using the HET-s prion fibril model, we show that amyloid formation can be monitored by measuring ThT fluorescence anisotropy. Kinetic parameters obtained by this method are identical to those determined by CD spectrometry. We propose that ThT anisotropy represent an interesting, simple and alternative technique to analyze the amyloid formation process.
- Published
- 2007
47. A Short History of Small s
- Author
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Sven J. Saupe
- Subjects
Models, Molecular ,Genetics ,biology ,Prions ,Inheritance (genetic algorithm) ,Review ,Cell Biology ,Fungus ,History, 20th Century ,biology.organism_classification ,History, 21st Century ,Biochemistry ,Podospora anserina ,Filamentous fungus ,Fungal prion ,Fungal Proteins ,Cellular and Molecular Neuroscience ,Infectious Diseases ,Podospora ,Genetic element ,Gene - Abstract
Prions are infectious proteins. In fungi, prions correspond to non-Mendelian genetic elements whose mode of inheritance has long eluded explanation. The [Het-s] cytoplasmic genetic element of the filamentous fungus Podospora anserina, was originally identified in 1952 and recognized as a prion nearly half a century later. The present chapter will attempt to describe the work on [Het-s] from a historical perspective. The initial characterization and early genetic and physiological studies of [Het-s] are described together with the isolation of the [Het-s] encoding gene. More recent work that led to the construction of a structural model for this prion is also discussed.
- Published
- 2007
48. Mass Analysis by Scanning Transmission Electron Microscopy and Electron Diffraction Validate Predictions of Stacked β-Solenoid Model of HET-s Prion Fibrils
- Author
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Joseph S. Wall, Alasdair C. Steven, Raimon Sabaté, Anindito Sen, Sven J. Saupe, Ulrich Baxa, and Martha N. Simon
- Subjects
Microscopy, Electron, Scanning Transmission ,Models, Molecular ,Amyloid ,Prions ,Protein subunit ,Stacking ,Cell Biology ,Biology ,biology.organism_classification ,Fibril ,Biochemistry ,Podospora anserina ,Protein Structure, Tertiary ,law.invention ,Fungal Proteins ,Crystallography ,Electron diffraction ,Podospora ,law ,Scanning transmission electron microscopy ,Electron microscope ,Molecular Biology - Abstract
Fungal prions are infectious filamentous polymers of proteins that are soluble in uninfected cells. In its prion form, the HET-s protein of Podospora anserina participates in a fungal self/non-self recognition phenomenon called heterokaryon incompatibility. Like other prion proteins, HET-s has a so-called "prion domain" (its C-terminal region, HET-s-(218-289)) that is responsible for induction and propagation of the prion in vivo and for fibril formation in vitro. Prion fibrils are thought to have amyloid backbones of polymerized prion domains. A relatively detailed model has been proposed for prion domain fibrils of HET-s based on a variety of experimental constraints (Ritter, C., Maddelein, M. L., Siemer, A. B., Luhrs, T., Ernst, M., Meier, B. H., Saupe, S. J., and Riek, R. (2005) Nature 435, 844-848). To test specific predictions of this model, which envisages axial stacking of beta-solenoids with two coils per subunit, we examined fibrils by electron microscopy. Electron diffraction gave a prominent meridional reflection at (0.47 nm)(-1), indicative of cross-beta structure, as predicted. STEM (scanning transmission electron microscopy) mass-per-unit-length measurements yielded 1.02 +/- 0.16 subunits per 0.94 nm, in agreement with the model prediction (1 subunit per 0.94 nm). This is half the packing density of approximately 1 subunit per 0.47 nm previously obtained for fibrils of the yeast prion proteins, Ure2p and Sup35p, whence it follows that the respective amyloid architectures are basically different.
- Published
- 2007
49. As a toxin dies a prion comes to life: A tentative natural history of the [Het-s] prion
- Author
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Sven J. Saupe and Asen Daskalov
- Subjects
Genetics ,Mutation ,Extra Views ,Innate immune system ,Amyloid ,Mechanism (biology) ,Prions ,Amino Acid Motifs ,Receptors, Cell Surface ,Cell Biology ,Exaptation ,Biology ,medicine.disease_cause ,Biochemistry ,Fungal prion ,Cell biology ,Evolution, Molecular ,Cellular and Molecular Neuroscience ,Infectious Diseases ,medicine ,Signal transduction ,Receptor ,Signal Transduction ,Toxins, Biological - Abstract
A variety of signaling pathways, in particular with roles in cell fate and host defense, operate by a prion-like mechanism consisting in the formation of open-ended oligomeric signaling complexes termed signalosomes. This mechanism emerges as a novel paradigm in signal transduction. Among the proteins forming such signaling complexes are the Nod-like receptors (NLR), involved in innate immunity. It now appears that the [Het-s] fungal prion derives from such a cell-fate defining signaling system controlled by a fungal NLR. What was once considered as an isolated oddity turns out to be related to a conserved and widespread signaling mechanism. Herein, we recall the relation of the [Het-s] prion to the signal transduction pathway controlled by the NWD2 Nod-like receptor, leading to activation of the HET-S pore-forming cell death execution protein. We explicit an evolutionary scenario in which formation of the [Het-s] prion is the result of an exaptation process or how a loss-of-function mutation in a pore-forming cell death execution protein (HET-S) has given birth to a functional prion ([Het-s]).
- Published
- 2015
50. Signal Transduction by a Fungal NOD-Like Receptor Based on Propagation of a Prion Amyloid Fold
- Author
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Antoine Loquet, Alfons J. M. Debets, Asen Daskalov, Raimon Sabaté, Birgit Habenstein, Sven J. Saupe, Denis Martinez, and Universitat de Barcelona
- Subjects
Amyloid ,QH301-705.5 ,Prions ,Amyloidogenic Proteins ,Receptors, Cell Surface ,Biology ,Cell fate determination ,Laboratorium voor Erfelijkheidsleer ,General Biochemistry, Genetics and Molecular Biology ,Podospora anserina ,diversity ,non-self recognition ,Fungal Proteins ,Podospora ,het-s(218-289) prion ,Biology (General) ,glycolipid transfer protein ,Genetics ,Fungal protein ,General Immunology and Microbiology ,General Neuroscience ,Fungal genetics ,Proteins ,podospora-anserina ,Amyloidosis ,biology.organism_classification ,PE&RC ,het-s prion ,cell-death ,Cell biology ,state nmr-spectroscopy ,Amiloïdosi ,Protein folding ,Laboratory of Genetics ,Signal transduction ,General Agricultural and Biological Sciences ,heterokaryon incompatibility gene ,Proteïnes ,vegetative incompatibility ,Research Article - Abstract
In the fungus Podospora anserina, the [Het-s] prion induces programmed cell death by activating the HET-S pore-forming protein. The HET-s β-solenoid prion fold serves as a template for converting the HET-S prion-forming domain into the same fold. This conversion, in turn, activates the HET-S pore-forming domain. The gene immediately adjacent to het-S encodes NWD2, a Nod-like receptor (NLR) with an N-terminal motif similar to the elementary repeat unit of the β-solenoid fold. NLRs are immune receptors controlling cell death and host defense processes in animals, plants and fungi. We have proposed that, analogously to [Het-s], NWD2 can activate the HET-S pore-forming protein by converting its prion-forming region into the β-solenoid fold. Here, we analyze the ability of NWD2 to induce formation of the β-solenoid prion fold. We show that artificial NWD2 variants induce formation of the [Het-s] prion, specifically in presence of their cognate ligands. The N-terminal motif is responsible for this prion induction, and mutations predicted to affect the β-solenoid fold abolish templating activity. In vitro, the N-terminal motif assembles into infectious prion amyloids that display a structure resembling the β-solenoid fold. In vivo, the assembled form of the NWD2 N-terminal region activates the HET-S pore-forming protein. This study documenting the role of the β-solenoid fold in fungal NLR function further highlights the general importance of amyloid and prion-like signaling in immunity-related cell fate pathways., The fungus Podospora anserina uses a prion amyloid fold as a signal transduction device between a Nod-like receptor and a downstream cell death execution protein., Author Summary Although amyloids are best known as protein aggregates that are responsible for fatal neurodegenerative diseases, amyloid structures can also fulfill functional roles in cells. In particular, the controlled formation of amyloid structures appears to be involved in different signaling processes in the context of programmed cell death and host defense. The [Het-s] prion of the filamentous fungus Podospora anserina is a model system in which the 3-D structure of the prion form has been solved. The [Het-s] prion works as an activation switch for a second protein termed HET-S. HET-S is a pore-forming protein that is activated when the [Het-s] prion causes its C-terminal domain to adopt an amyloid-like fold. The protein encoded by the gene adjacent to het-S is a Nod-like receptor (NLR) called NWD2. NLRs are immune receptors that control host defense and cell death processes in plants, animals, and fungi. We show that NWD2 can template the formation of the [Het-s] prion fold in a ligand-controlled manner. NWD2 has an N-terminal motif homologous to the HET-S/s prion-forming region; we find that this region is both necessary and sufficient for its prion-inducing activity, and our functional and structural approaches reveal that the N-terminal region of NWD2 adopts a fold closely related to that of the HET-S/s prion. This study illustrates how the controlled formation of a prion amyloid fold can be used in a signaling process whereby a Nod-like receptor protein activates a downstream cell death execution domain.
- Published
- 2015
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