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Levrier A, Karpathakis I, Nash B, Bowden SD, Lindner AB, Noireaux V. PHEIGES: all-cell-free phage synthesis and selection from engineered genomes. Nat Commun 2024; 15:2223. [PMID: 38472230 PMCID: PMC10933291 DOI: 10.1038/s41467-024-46585-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Bacteriophages constitute an invaluable biological reservoir for biotechnology and medicine. The ability to exploit such vast resources is hampered by the lack of methods to rapidly engineer, assemble, package genomes, and select phages. Cell-free transcription-translation (TXTL) offers experimental settings to address such a limitation. Here, we describe PHage Engineering by In vitro Gene Expression and Selection (PHEIGES) using T7 phage genome and Escherichia coli TXTL. Phage genomes are assembled in vitro from PCR-amplified fragments and directly expressed in batch TXTL reactions to produce up to 1011 PFU/ml engineered phages within one day. We further demonstrate a significant genotype-phenotype linkage of phage assembly in bulk TXTL. This enables rapid selection of phages with altered rough lipopolysaccharides specificity from phage genomes incorporating tail fiber mutant libraries. We establish the scalability of PHEIGES by one pot assembly of such mutants with fluorescent gene integration and 10% length-reduced genome.
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Affiliation(s)
- Antoine Levrier
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Université Paris Cité, INSERM U1284, Center for Research and Interdisciplinarity, F-75006, Paris, France
| | - Ioannis Karpathakis
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Facultatea de Biotehnologii, USAMV Bucuresti, Sector 1, Cod 011464, Bucureşti, Romania
| | - Bruce Nash
- DNA Learning Center, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Steven D Bowden
- Department of Food Science and Nutrition, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Ariel B Lindner
- Université Paris Cité, INSERM U1284, Center for Research and Interdisciplinarity, F-75006, Paris, France.
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA.
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2
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Carbo-Tano M, Lapoix M, Jia X, Thouvenin O, Pascucci M, Auclair F, Quan FB, Albadri S, Aguda V, Farouj Y, Hillman EMC, Portugues R, Del Bene F, Thiele TR, Dubuc R, Wyart C. The mesencephalic locomotor region recruits V2a reticulospinal neurons to drive forward locomotion in larval zebrafish. Nat Neurosci 2023; 26:1775-1790. [PMID: 37667039 PMCID: PMC10545542 DOI: 10.1038/s41593-023-01418-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/24/2023] [Indexed: 09/06/2023]
Abstract
The mesencephalic locomotor region (MLR) is a brain stem area whose stimulation triggers graded forward locomotion. How MLR neurons recruit downstream vsx2+ (V2a) reticulospinal neurons (RSNs) is poorly understood. Here, to overcome this challenge, we uncovered the locus of MLR in transparent larval zebrafish and show that the MLR locus is distinct from the nucleus of the medial longitudinal fasciculus. MLR stimulations reliably elicit forward locomotion of controlled duration and frequency. MLR neurons recruit V2a RSNs via projections onto somata in pontine and retropontine areas, and onto dendrites in the medulla. High-speed volumetric imaging of neuronal activity reveals that strongly MLR-coupled RSNs are active for steering or forward swimming, whereas weakly MLR-coupled medullary RSNs encode the duration and frequency of the forward component. Our study demonstrates how MLR neurons recruit specific V2a RSNs to control the kinematics of forward locomotion and suggests conservation of the motor functions of V2a RSNs across vertebrates.
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Affiliation(s)
- Martin Carbo-Tano
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France
| | - Mathilde Lapoix
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France
| | - Xinyu Jia
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France
| | - Olivier Thouvenin
- Institut Langevin, École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Paris, France
| | - Marco Pascucci
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France
- Université Paris-Saclay, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Centre National de la Recherche Scientifique, NeuroSpin, Baobab, Centre d'études de Saclay, Gif-sur-Yvette, France
- The American University of Paris, Paris, France
| | - François Auclair
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréal, Quebec, Canada
| | - Feng B Quan
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France
| | - Shahad Albadri
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris, France
| | - Vernie Aguda
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Younes Farouj
- Institute of Neuroscience, Technical University of Munich, Munich, Germany
| | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Kavli Institute for Brain Science, Columbia University, New York, NY, USA
| | - Ruben Portugues
- Institute of Neuroscience, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Filippo Del Bene
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris, France
| | - Tod R Thiele
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Réjean Dubuc
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréal, Quebec, Canada.
- Groupe de Recherche en Activité Physique Adaptée, Department of Exercise Science, Université du Québec à Montréal, Montréal, Quebec, Canada.
| | - Claire Wyart
- Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France.
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3
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Chang LH, Ghosh S, Papale A, Luppino JM, Miranda M, Piras V, Degrouard J, Edouard J, Poncelet M, Lecouvreur N, Bloyer S, Leforestier A, Joyce EF, Holcman D, Noordermeer D. Multi-feature clustering of CTCF binding creates robustness for loop extrusion blocking and Topologically Associating Domain boundaries. Nat Commun 2023; 14:5615. [PMID: 37699887 PMCID: PMC10497529 DOI: 10.1038/s41467-023-41265-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/28/2023] [Indexed: 09/14/2023] Open
Abstract
Topologically Associating Domains (TADs) separate vertebrate genomes into insulated regulatory neighborhoods that focus genome-associated processes. TADs are formed by Cohesin-mediated loop extrusion, with many TAD boundaries consisting of clustered binding sites of the CTCF insulator protein. Here we determine how this clustering of CTCF binding contributes to the blocking of loop extrusion and the insulation between TADs. We identify enrichment of three features of CTCF binding at strong TAD boundaries, consisting of strongly bound and closely spaced CTCF binding peaks, with a further enrichment of DNA-binding motifs within these peaks. Using multi-contact Nano-C analysis in cells with normal and perturbed CTCF binding, we establish that individual CTCF binding sites contribute to the blocking of loop extrusion, but in an incomplete manner. When clustered, individual CTCF binding sites thus create a stepwise insulation between neighboring TADs. Based on these results, we propose a model whereby multiple instances of temporal loop extrusion blocking create strong insulation between TADs.
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Affiliation(s)
- Li-Hsin Chang
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, and National Institute of Health Research, Blood and Transplant Research Unit in Precision Cellular Therapeutics, OX3 9DS, Oxford, UK
| | - Sourav Ghosh
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
- Department of Pathology and Laboratory Medicine, Western University, N6A3K7, London, ON, Canada
| | - Andrea Papale
- École Normale Supérieure, IBENS, Université PSL, 75005, Paris, France
| | - Jennifer M Luppino
- Department of Genetics, Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mélanie Miranda
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Vincent Piras
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jéril Degrouard
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides (LPS), 91405, Orsay, France
| | - Joanne Edouard
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Mallory Poncelet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Nathan Lecouvreur
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Sébastien Bloyer
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Amélie Leforestier
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides (LPS), 91405, Orsay, France
| | - Eric F Joyce
- Department of Genetics, Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David Holcman
- École Normale Supérieure, IBENS, Université PSL, 75005, Paris, France
- Churchill College, University of Cambridge, CB3 0DS, Cambridge, UK
| | - Daan Noordermeer
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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4
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Desbordes T, Lakretz Y, Chanoine V, Oquab M, Badier JM, Trébuchon A, Carron R, Bénar CG, Dehaene S, King JR. Dimensionality and Ramping: Signatures of Sentence Integration in the Dynamics of Brains and Deep Language Models. J Neurosci 2023; 43:5350-5364. [PMID: 37217308 PMCID: PMC10359032 DOI: 10.1523/jneurosci.1163-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 02/07/2023] [Accepted: 02/19/2023] [Indexed: 05/24/2023] Open
Abstract
A sentence is more than the sum of its words: its meaning depends on how they combine with one another. The brain mechanisms underlying such semantic composition remain poorly understood. To shed light on the neural vector code underlying semantic composition, we introduce two hypotheses: (1) the intrinsic dimensionality of the space of neural representations should increase as a sentence unfolds, paralleling the growing complexity of its semantic representation; and (2) this progressive integration should be reflected in ramping and sentence-final signals. To test these predictions, we designed a dataset of closely matched normal and jabberwocky sentences (composed of meaningless pseudo words) and displayed them to deep language models and to 11 human participants (5 men and 6 women) monitored with simultaneous MEG and intracranial EEG. In both deep language models and electrophysiological data, we found that representational dimensionality was higher for meaningful sentences than jabberwocky. Furthermore, multivariate decoding of normal versus jabberwocky confirmed three dynamic patterns: (1) a phasic pattern following each word, peaking in temporal and parietal areas; (2) a ramping pattern, characteristic of bilateral inferior and middle frontal gyri; and (3) a sentence-final pattern in left superior frontal gyrus and right orbitofrontal cortex. These results provide a first glimpse into the neural geometry of semantic integration and constrain the search for a neural code of linguistic composition.SIGNIFICANCE STATEMENT Starting from general linguistic concepts, we make two sets of predictions in neural signals evoked by reading multiword sentences. First, the intrinsic dimensionality of the representation should grow with additional meaningful words. Second, the neural dynamics should exhibit signatures of encoding, maintaining, and resolving semantic composition. We successfully validated these hypotheses in deep neural language models, artificial neural networks trained on text and performing very well on many natural language processing tasks. Then, using a unique combination of MEG and intracranial electrodes, we recorded high-resolution brain data from human participants while they read a controlled set of sentences. Time-resolved dimensionality analysis showed increasing dimensionality with meaning, and multivariate decoding allowed us to isolate the three dynamical patterns we had hypothesized.
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Affiliation(s)
- Théo Desbordes
- Meta AI Research, Paris 75002, France; and Cognitive Neuroimaging Unit NeuroSpin center, 91191, Gif-sur-Yvette, France
| | - Yair Lakretz
- Cognitive Neuroimaging Unit NeuroSpin center, Gif-sur-Yvette, 91191, France
| | - Valérie Chanoine
- Institute of Language, Communication and the Brain, Aix-en-Provence, 13100, France; and Aix-Marseille Université, Centre National de la Recherche Scientifique, LPL, Aix-en-Provence, 13100, France
| | | | - Jean-Michel Badier
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, CNRS, LPL, Aix-en-Provence 13100; and Inst Neurosci Syst, Marseille, 13005, France
| | - Agnès Trébuchon
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, CNRS, LPL, Aix-en-Provence 13100, France; and Inst Neurosci Syst, Marseille, 13005, France; and Assistance Publique Hopitaux de Marseille, Timone hospital, Epileptology and Cerebral Rythmology, Marseille, 13385, France
| | - Romain Carron
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, CNRS, LPL, Aix-en-Provence 13100, France; and Inst Neurosci Syst, Marseille, 13005, France; and Assistance Publique Hopitaux de Marseille, Timone hospital, Functional and Stereotactic Neurosurgery, Marseille, 13385, France
| | - Christian-G Bénar
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, CNRS, LPL, Aix-en-Provence 13100, France; and Inst Neurosci Syst, Marseille, 13005, France
| | - Stanislas Dehaene
- Université Paris Saclay, Institut National de la Santé et de la Recherche Médicale, Commissariat à l'Energie Atomique, Cognitive Neuroimaging Unit, NeuroSpin center, Saclay, 91191, France; and Collège de France, PSL University, Paris, 75231, France
| | - Jean-Rémi King
- Meta AI Research, Paris 75002, France; and Cognitive Neuroimaging Unit NeuroSpin center, 91191, Gif-sur-Yvette, France
- LSP, École normale supérieure, PSL (Paris Sciences & Lettres) University, CNRS, 75005 Paris, France
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5
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Rolland T, Cliquet F, Anney RJL, Moreau C, Traut N, Mathieu A, Huguet G, Duan J, Warrier V, Portalier S, Dry L, Leblond CS, Douard E, Amsellem F, Malesys S, Maruani A, Toro R, Børglum AD, Grove J, Baron-Cohen S, Packer A, Chung WK, Jacquemont S, Delorme R, Bourgeron T. Phenotypic effects of genetic variants associated with autism. Nat Med 2023; 29:1671-1680. [PMID: 37365347 PMCID: PMC10353945 DOI: 10.1038/s41591-023-02408-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/19/2023] [Indexed: 06/28/2023]
Abstract
While over 100 genes have been associated with autism, little is known about the prevalence of variants affecting them in individuals without a diagnosis of autism. Nor do we fully appreciate the phenotypic diversity beyond the formal autism diagnosis. Based on data from more than 13,000 individuals with autism and 210,000 undiagnosed individuals, we estimated the odds ratios for autism associated to rare loss-of-function (LoF) variants in 185 genes associated with autism, alongside 2,492 genes displaying intolerance to LoF variants. In contrast to autism-centric approaches, we investigated the correlates of these variants in individuals without a diagnosis of autism. We show that these variants are associated with a small but significant decrease in fluid intelligence, qualification level and income and an increase in metrics related to material deprivation. These effects were larger for autism-associated genes than in other LoF-intolerant genes. Using brain imaging data from 21,040 individuals from the UK Biobank, we could not detect significant differences in the overall brain anatomy between LoF carriers and non-carriers. Our results highlight the importance of studying the effect of the genetic variants beyond categorical diagnosis and the need for more research to understand the association between these variants and sociodemographic factors, to best support individuals carrying these variants.
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Affiliation(s)
- Thomas Rolland
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France.
| | - Freddy Cliquet
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Richard J L Anney
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Clara Moreau
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Nicolas Traut
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
- Center for Research and Interdisciplinarity (CRI), Université Paris Descartes, Paris, France
| | - Alexandre Mathieu
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Guillaume Huguet
- Centre de Recherche du Centre Hospitalier Universitaire Sainte-Justine, Montréal, Québec, Canada
| | - Jinjie Duan
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine and the iSEQ Centre, Aarhus University, Aarhus, Denmark
- Center for Genomics and Personalized Medicine, Aarhus, Denmark
| | - Varun Warrier
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Swan Portalier
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Louise Dry
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Claire S Leblond
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Elise Douard
- Centre de Recherche du Centre Hospitalier Universitaire Sainte-Justine, Montréal, Québec, Canada
- Département de Pédiatrie, Université de Montréal, Montréal, Québec, Canada
| | - Frédérique Amsellem
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
- Department of Child and Adolescent Psychiatry, Robert Debré Hospital, APHP, Paris, France
| | - Simon Malesys
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
| | - Anna Maruani
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
- Department of Child and Adolescent Psychiatry, Robert Debré Hospital, APHP, Paris, France
| | - Roberto Toro
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
- Center for Research and Interdisciplinarity (CRI), Université Paris Descartes, Paris, France
| | - Anders D Børglum
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine and the iSEQ Centre, Aarhus University, Aarhus, Denmark
- Center for Genomics and Personalized Medicine, Aarhus, Denmark
| | - Jakob Grove
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine and the iSEQ Centre, Aarhus University, Aarhus, Denmark
- Center for Genomics and Personalized Medicine, Aarhus, Denmark
- Bioinformatics Research Centre, Aarhus University, Aarhus, Denmark
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK
| | | | - Wendy K Chung
- Simons Foundation, New York, NY, USA
- Department of Pediatrics, Columbia University Medical Center, New York, NY, USA
| | - Sébastien Jacquemont
- Centre de Recherche du Centre Hospitalier Universitaire Sainte-Justine, Montréal, Québec, Canada
- Département de Pédiatrie, Université de Montréal, Montréal, Québec, Canada
| | - Richard Delorme
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France
- Department of Child and Adolescent Psychiatry, Robert Debré Hospital, APHP, Paris, France
| | - Thomas Bourgeron
- Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, IUF, Université Paris Cité, Paris, France.
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6
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Faini G, Tanese D, Molinier C, Telliez C, Hamdani M, Blot F, Tourain C, de Sars V, Del Bene F, Forget BC, Ronzitti E, Emiliani V. Ultrafast light targeting for high-throughput precise control of neuronal networks. Nat Commun 2023; 14:1888. [PMID: 37019891 PMCID: PMC10074378 DOI: 10.1038/s41467-023-37416-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 03/16/2023] [Indexed: 04/07/2023] Open
Abstract
Two-photon, single-cell resolution optogenetics based on holographic light-targeting approaches enables the generation of precise spatiotemporal neuronal activity patterns and thus a broad range of experimental applications, such as high throughput connectivity mapping and probing neural codes for perception. Yet, current holographic approaches limit the resolution for tuning the relative spiking time of distinct cells to a few milliseconds, and the achievable number of targets to 100-200, depending on the working depth. To overcome these limitations and expand the capabilities of single-cell optogenetics, we introduce an ultra-fast sequential light targeting (FLiT) optical configuration based on the rapid switching of a temporally focused beam between holograms at kHz rates. We used FLiT to demonstrate two illumination protocols, termed hybrid- and cyclic-illumination, and achieve sub-millisecond control of sequential neuronal activation and high throughput multicell illumination in vitro (mouse organotypic and acute brain slices) and in vivo (zebrafish larvae and mice), while minimizing light-induced thermal rise. These approaches will be important for experiments that require rapid and precise cell stimulation with defined spatio-temporal activity patterns and optical control of large neuronal ensembles.
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Affiliation(s)
- Giulia Faini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Dimitrii Tanese
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Clément Molinier
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Cécile Telliez
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Massilia Hamdani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Francois Blot
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Christophe Tourain
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Vincent de Sars
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Filippo Del Bene
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Benoît C Forget
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Emiliano Ronzitti
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France.
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France.
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7
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Jones R, Hons M, Rabah N, Zamarreño N, Arranz R, Reguera J. Structural basis and dynamics of Chikungunya alphavirus RNA capping by nsP1 capping pores. Proc Natl Acad Sci U S A 2023; 120:e2213934120. [PMID: 36913573 PMCID: PMC10041110 DOI: 10.1073/pnas.2213934120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
Abstract
Alphaviruses are emerging positive-stranded RNA viruses which replicate and transcribe their genomes in membranous organelles formed in the cell cytoplasm. The nonstructural protein 1 (nsP1) is responsible for viral RNA capping and gates the replication organelles by assembling into monotopic membrane-associated dodecameric pores. The capping pathway is unique to Alphaviruses; beginning with the N7 methylation of a guanosine triphosphate (GTP) molecule, followed by the covalent linkage of an m7GMP group to a conserved histidine in nsP1 and the transfer of this cap structure to a diphosphate RNA. Here, we provide structural snapshots of different stages of the reaction pathway showing how nsP1 pores recognize the substrates of the methyl-transfer reaction, GTP and S-adenosyl methionine (SAM), how the enzyme reaches a metastable postmethylation state with SAH and m7GTP in the active site, and the subsequent covalent transfer of m7GMP to nsP1 triggered by the presence of RNA and postdecapping reaction conformational changes inducing the opening of the pore. In addition, we biochemically characterize the capping reaction, demonstrating specificity for the RNA substrate and the reversibility of the cap transfer resulting in decapping activity and the release of reaction intermediates. Our data identify the molecular determinants allowing each pathway transition, providing an explanation for the need for the SAM methyl donor all along the pathway and clues about the conformational rearrangements associated to the enzymatic activity of nsP1. Together, our results set ground for the structural and functional understanding of alphavirus RNA-capping and the design of antivirals.
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Affiliation(s)
- Rhian Jones
- Aix-Marseille Université, CNRS, Architecture et Fonction des Macromolécules Biologiques UMR 7257, 13288 Marseille, France
| | - Michael Hons
- European Molecular Biology Laboratory, 38042 Grenoble Cedex 9, France
| | - Nadia Rabah
- Aix-Marseille Université, CNRS, Architecture et Fonction des Macromolécules Biologiques UMR 7257, 13288 Marseille, France
| | - Noelia Zamarreño
- National Center of Biotechnology, Consejo Superior de Investigaciones Cientificas, 28049 Madrid, Spain
| | - Rocío Arranz
- National Center of Biotechnology, Consejo Superior de Investigaciones Cientificas, 28049 Madrid, Spain
| | - Juan Reguera
- Aix-Marseille Université, CNRS, Architecture et Fonction des Macromolécules Biologiques UMR 7257, 13288 Marseille, France
- INSERM, Architecture et Fonction des Macromolécules Biologiques UMR 7257, 13288 Marseille, France
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8
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Najafi J, Dmitrieff S, Minc N. Size- and position-dependent cytoplasm viscoelasticity through hydrodynamic interactions with the cell surface. Proc Natl Acad Sci U S A 2023; 120:e2216839120. [PMID: 36802422 PMCID: PMC9992773 DOI: 10.1073/pnas.2216839120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/23/2023] [Indexed: 02/23/2023] Open
Abstract
Many studies of cytoplasm rheology have focused on small components in the submicrometer scale. However, the cytoplasm also baths large organelles like nuclei, microtubule asters, or spindles that often take significant portions of cells and move across the cytoplasm to regulate cell division or polarization. Here, we translated passive components of sizes ranging from few up to ~50 percents of the cell diameter, through the vast cytoplasm of live sea urchin eggs, with calibrated magnetic forces. Creep and relaxation responses indicate that for objects larger than the micron size, the cytoplasm behaves as a Jeffreys material, viscoelastic at short timescales, and fluidizing at longer times. However, as component size approached that of cells, cytoplasm viscoelastic resistance increased in a nonmonotonic manner. Flow analysis and simulations suggest that this size-dependent viscoelasticity emerges from hydrodynamic interactions between the moving object and the static cell surface. This effect also yields to position-dependent viscoelasticity with objects initially closer to the cell surface being harder to displace. These findings suggest that the cytoplasm hydrodynamically couples large organelles to the cell surface to restrain their motion, with important implications for cell shape sensing and cellular organization.
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Affiliation(s)
- Javad Najafi
- Université de Paris, CNRS, Institut Jacques Monod,75006Paris, France
- Equipe Labellisée Ligue Contre le Cancer, 75013Paris, France
| | - Serge Dmitrieff
- Université de Paris, CNRS, Institut Jacques Monod,75006Paris, France
- Equipe Labellisée Ligue Contre le Cancer, 75013Paris, France
| | - Nicolas Minc
- Université de Paris, CNRS, Institut Jacques Monod,75006Paris, France
- Equipe Labellisée Ligue Contre le Cancer, 75013Paris, France
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9
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Antoniou P, Hardouin G, Martinucci P, Frati G, Felix T, Chalumeau A, Fontana L, Martin J, Masson C, Brusson M, Maule G, Rosello M, Giovannangeli C, Abramowski V, de Villartay JP, Concordet JP, Del Bene F, El Nemer W, Amendola M, Cavazzana M, Cereseto A, Romano O, Miccio A. Base-editing-mediated dissection of a γ-globin cis-regulatory element for the therapeutic reactivation of fetal hemoglobin expression. Nat Commun 2022; 13:6618. [PMID: 36333351 PMCID: PMC9636226 DOI: 10.1038/s41467-022-34493-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Sickle cell disease and β-thalassemia affect the production of the adult β-hemoglobin chain. The clinical severity is lessened by mutations that cause fetal γ-globin expression in adult life (i.e., the hereditary persistence of fetal hemoglobin). Mutations clustering ~200 nucleotides upstream of the HBG transcriptional start sites either reduce binding of the LRF repressor or recruit the KLF1 activator. Here, we use base editing to generate a variety of mutations in the -200 region of the HBG promoters, including potent combinations of four to eight γ-globin-inducing mutations. Editing of patient hematopoietic stem/progenitor cells is safe, leads to fetal hemoglobin reactivation and rescues the pathological phenotype. Creation of a KLF1 activator binding site is the most potent strategy - even in long-term repopulating hematopoietic stem/progenitor cells. Compared with a Cas9-nuclease approach, base editing avoids the generation of insertions, deletions and large genomic rearrangements and results in higher γ-globin levels. Our results demonstrate that base editing of HBG promoters is a safe, universal strategy for treating β-hemoglobinopathies.
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Affiliation(s)
- Panagiotis Antoniou
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Giulia Hardouin
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
- Université Paris Cité, Imagine Institute, Laboratory of Human Lymphohematopoiesis, INSERM UMR 1163, 75015, Paris, France
- Biotherapy Department and Clinical Investigation Center, Assistance Publique Hopitaux de Paris, INSERM, 75015, Paris, France
| | - Pierre Martinucci
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Giacomo Frati
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Tristan Felix
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Anne Chalumeau
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Letizia Fontana
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Jeanne Martin
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Cecile Masson
- Bioinformatics Platform, Imagine Institute, 75015, Paris, France
| | - Megane Brusson
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France
| | - Giulia Maule
- CIBIO, University of Trento, 38100, Trento, Italy
| | - Marion Rosello
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75015, Paris, France
| | | | - Vincent Abramowski
- Université Paris Cité, Imagine Institute, Laboratory of genome dynamics in the immune system, INSERM UMR 1163, 75015, Paris, France
| | - Jean-Pierre de Villartay
- Université Paris Cité, Imagine Institute, Laboratory of genome dynamics in the immune system, INSERM UMR 1163, 75015, Paris, France
| | - Jean-Paul Concordet
- INSERM U1154, CNRS UMR7196, Museum National d'Histoire Naturelle, Paris, France
| | - Filippo Del Bene
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75015, Paris, France
| | - Wassim El Nemer
- Établissement Français du Sang, UMR 7268, 13005, Marseille, France
- Laboratoire d'Excellence GR-Ex, 75015, Paris, France
| | - Mario Amendola
- Genethon, 91000, Evry, France
- Université Paris-Saclay, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Marina Cavazzana
- Biotherapy Department and Clinical Investigation Center, Assistance Publique Hopitaux de Paris, INSERM, 75015, Paris, France
- Université Paris Cité, 75015, Paris, France
- Imagine Institute, 75015, Paris, France
| | | | - Oriana Romano
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Annarita Miccio
- Université Paris Cité, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, 75015, Paris, France.
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10
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Tesson F, Hervé A, Mordret E, Touchon M, d'Humières C, Cury J, Bernheim A. Systematic and quantitative view of the antiviral arsenal of prokaryotes. Nat Commun 2022; 13:2561. [PMID: 35538097 PMCID: PMC9090908 DOI: 10.1038/s41467-022-30269-9] [Citation(s) in RCA: 133] [Impact Index Per Article: 66.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/22/2022] [Indexed: 12/16/2022] Open
Abstract
Bacteria and archaea have developed multiple antiviral mechanisms, and genomic evidence indicates that several of these antiviral systems co-occur in the same strain. Here, we introduce DefenseFinder, a tool that automatically detects known antiviral systems in prokaryotic genomes. We use DefenseFinder to analyse 21000 fully sequenced prokaryotic genomes, and find that antiviral strategies vary drastically between phyla, species and strains. Variations in composition of antiviral systems correlate with genome size, viral threat, and lifestyle traits. DefenseFinder will facilitate large-scale genomic analysis of antiviral defense systems and the study of host-virus interactions in prokaryotes.
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Affiliation(s)
- Florian Tesson
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- SEED, U1284, INSERM, Université de Paris, Paris, France
| | | | | | - Marie Touchon
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France
| | | | - Jean Cury
- SEED, U1284, INSERM, Université de Paris, Paris, France.
- Université Paris-Saclay, CNRS, INRIA, Laboratoire Interdisciplinaire des Sciences du Numérique, UMR, 9015, Orsay, France.
| | - Aude Bernheim
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France.
- SEED, U1284, INSERM, Université de Paris, Paris, France.
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11
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Ben Amar D, Thoinet K, Villalard B, Imbaud O, Costechareyre C, Jarrosson L, Reynaud F, Novion Ducassou J, Couté Y, Brunet JF, Combaret V, Corradini N, Delloye-Bourgeois C, Castellani V. Environmental cues from neural crest derivatives act as metastatic triggers in an embryonic neuroblastoma model. Nat Commun 2022; 13:2549. [PMID: 35538114 PMCID: PMC9091272 DOI: 10.1038/s41467-022-30237-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
Embryonic malignant transformation is concomitant to organogenesis, often affecting multipotent and migratory progenitors. While lineage relationships between malignant cells and their physiological counterparts are extensively investigated, the contribution of exogenous embryonic signals is not fully known. Neuroblastoma (NB) is a childhood malignancy of the peripheral nervous system arising from the embryonic trunk neural crest (NC) and characterized by heterogeneous and interconvertible tumor cell identities. Here, using experimental models mimicking the embryonic context coupled to proteomic and transcriptomic analyses, we show that signals released by embryonic sympathetic ganglia, including Olfactomedin-1, induce NB cells to shift from a noradrenergic to mesenchymal identity, and to activate a gene program promoting NB metastatic onset and dissemination. From this gene program, we extract a core signature specifically shared by metastatic cancers with NC origin. This reveals non-cell autonomous embryonic contributions regulating the plasticity of NB identities and setting pro-dissemination gene programs common to NC-derived cancers.
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Affiliation(s)
- Dounia Ben Amar
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller
| | - Karine Thoinet
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller
| | - Benjamin Villalard
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller
| | - Olivier Imbaud
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller
| | | | | | - Florie Reynaud
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller
| | - Julia Novion Ducassou
- University Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048 38000, Grenoble, France
| | - Yohann Couté
- University Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048 38000, Grenoble, France
| | - Jean-François Brunet
- Institut de Biologie de l'ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research University, Paris, France
| | - Valérie Combaret
- Laboratory of Translational Research, Léon Bérard Centre, Lyon, France
| | - Nadège Corradini
- Departments of Oncology and Clinical Research, Centre Léon Berard and Institut d'Hématologie et d'Oncologie Pédiatrique, Lyon, France
| | - Céline Delloye-Bourgeois
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller.
| | - Valérie Castellani
- University of Lyon, University Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, NeuroMyoGene Institute, 69008, Lyon, France, 8 avenue Rockefeller.
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12
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Abstract
The classic two-hit model posits that both alleles of a tumor suppressor gene (TSG) must be inactivated to cause cancer. In contrast, for some oncogenes and haploinsufficient TSGs, a single genetic alteration can suffice to increase tumor fitness. Here, by quantifying the interactions between mutations and copy number alterations (CNAs) across 10,000 tumors, we show that many cancer genes actually switch between acting as one-hit or two-hit drivers. Third order genetic interactions identify the causes of some of these switches in dominance and dosage sensitivity as mutations in other genes in the same biological pathway. The correct genetic model for a gene thus depends on the other mutations in a genome, with a second hit in the same gene or an alteration in a different gene in the same pathway sometimes representing alternative evolutionary paths to cancer.
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Affiliation(s)
- Solip Park
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain.
| | - Fran Supek
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
| | - Ben Lehner
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), Barcelona, Spain.
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13
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Avellaneda J, Rodier C, Daian F, Brouilly N, Rival T, Luis NM, Schnorrer F. Myofibril and mitochondria morphogenesis are coordinated by a mechanical feedback mechanism in muscle. Nat Commun 2021; 12:2091. [PMID: 33828099 PMCID: PMC8027795 DOI: 10.1038/s41467-021-22058-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 02/23/2021] [Indexed: 02/01/2023] Open
Abstract
Complex animals build specialised muscles to match specific biomechanical and energetic needs. Hence, composition and architecture of sarcomeres and mitochondria are muscle type specific. However, mechanisms coordinating mitochondria with sarcomere morphogenesis are elusive. Here we use Drosophila muscles to demonstrate that myofibril and mitochondria morphogenesis are intimately linked. In flight muscles, the muscle selector spalt instructs mitochondria to intercalate between myofibrils, which in turn mechanically constrain mitochondria into elongated shapes. Conversely in cross-striated leg muscles, mitochondria networks surround myofibril bundles, contacting myofibrils only with thin extensions. To investigate the mechanism causing these differences, we manipulated mitochondrial dynamics and found that increased mitochondrial fusion during myofibril assembly prevents mitochondrial intercalation in flight muscles. Strikingly, this causes the expression of cross-striated muscle specific sarcomeric proteins. Consequently, flight muscle myofibrils convert towards a partially cross-striated architecture. Together, these data suggest a biomechanical feedback mechanism downstream of spalt synchronizing mitochondria with myofibril morphogenesis.
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Affiliation(s)
- Jerome Avellaneda
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Clement Rodier
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Fabrice Daian
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Nicolas Brouilly
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Thomas Rival
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Nuno Miguel Luis
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France.
| | - Frank Schnorrer
- Aix Marseille University, CNRS, IBDM, Turing Center for Living Systems, Marseille, France.
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14
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Abstract
GABAA receptors mediate most inhibitory synaptic transmission in the brain of vertebrates. Following GABA binding and fast activation, these receptors undergo a slower desensitization, the conformational pathway of which remains largely elusive. To explore the mechanism of desensitization, we used concatemeric α1β2γ2 GABAA receptors to selectively introduce gain-of-desensitization mutations one subunit at a time. A library of twenty-six mutant combinations was generated and their bi-exponential macroscopic desensitization rates measured. Introducing mutations at the different subunits shows a strongly asymmetric pattern with a key contribution of the γ2 subunit, and combining mutations results in marked synergistic effects indicating a non-concerted mechanism. Kinetic modelling indeed suggests a pathway where subunits move independently, the desensitization of two subunits being required to occlude the pore. Our work thus hints towards a very diverse and labile conformational landscape during desensitization, with potential implications in physiology and pharmacology.
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Affiliation(s)
- Marc Gielen
- Channel Receptors Unit, Institut Pasteur, CNRS UMR 3571, 25 rue du Docteur Roux, 75015, Paris, France.
- Sorbonne Université, 21 rue de l'École de Médecine, 75006, Paris, France.
| | - Nathalie Barilone
- Channel Receptors Unit, Institut Pasteur, CNRS UMR 3571, 25 rue du Docteur Roux, 75015, Paris, France
| | - Pierre-Jean Corringer
- Channel Receptors Unit, Institut Pasteur, CNRS UMR 3571, 25 rue du Docteur Roux, 75015, Paris, France
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