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4 results on '"Mercier, Marine"'

1. Constitutive sodium permeability in a Caenorhabditis elegans two-pore domain potassium channel.

Author

Andrini, Olga, Soussia, Ismail Ben, Tardy, Philippe, Walker, Denise S., Peña-Varas, Carlos, Ramírez, David, Gendrel, Marie, Mercier, Marine, El Mouridi, Sonia, Leclercq-Blondel, Alice, González, Wendy, Schafer, William R., Jospin, Maelle, and Boulin, Thomas

Subjects
POTASSIUM channels, MOLECULAR dynamics, CELL membranes, IONS, CAENORHABDITIS elegans
Abstract

Two-pore domain potassium (K2P) channels play a central role in modulating cellular excitability and neuronal function. The unique structure of the selectivity filter in K2P and other potassium channels determines their ability to allow the selective passage of potassium ions across cell membranes. The nematode C. elegans has one of the largest K2P families, with 47 subunit-coding genes. This remarkable expansion has been accompanied by the evolution of atypical selectivity filter sequences that diverge from the canonical TxGYG motif. Whether and how this sequence variation may impact the function of K2P channels has not been investigated so far. Here, we show that the UNC-58 K2P channel is constitutively permeable to sodium ions and that a cysteine residue in its selectivity filter is responsible for this atypical behavior. Indeed, by performing in vivo electrophysiological recordings and Ca2+ imaging experiments, we demonstrate that UNC-58 has a depolarizing effect in muscles and sensory neurons. Consistently, unc-58 gain-of-function mutants are hypercontracted, unlike the relaxed phenotype observed in hyperactive mutants of many neuromuscular K2P channels. Finally, by combining molecular dynamics simulations with functional studies in Xenopus laevis oocytes, we show that the atypical cysteine residue plays a key role in the unconventional sodium permeability of UNC-58. As predicting the consequences of selectivity filter sequence variations in silico remains a major challenge, our study illustrates how functional experiments are essential to determine the contribution of such unusual potassium channels to the electrical profile of excitable cells. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Reliable CRISPR/Cas9 Genome Engineering in Caenorhabditis elegans Using a Single Efficient sgRNA and an Easily Recognizable Phenotype

Author

El Mouridi, Sonia, Lecroisey, Claire, Tardy, Philippe, Mercier, Marine, Leclercq-Blondel, Alice, Zariohi, Nora, Boulin, Thomas, Institut NeuroMyoGène (INMG), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Boulin, Thomas, and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
[SDV.GEN]Life Sciences [q-bio]/Genetics, Genome, Helminth, mScarlet, [SDV.GEN] Life Sciences [q-bio]/Genetics, QH426-470, Investigations, Phenotype, coconversion, dpy-10, Gene Targeting, Genetics, Animals, CRISPR/Cas9 genome engineering, Collagen, CRISPR-Cas Systems, Caenorhabditis elegans, Caenorhabditis elegans Proteins, RNA, Guide, Kinetoplastida
Abstract

International audience; CRISPR/Cas9 genome engineering strategies allow the directed modification of the Caenorhabditis elegans genome to introduce point mutations, generate knock-out mutants, and insert coding sequences for epitope or fluorescent tags. Three practical aspects, however, complicate such experiments. First, the efficiency and specificity of single-guide RNAs (sgRNA) cannot be reliably predicted. Second, the detection of animals carrying genome edits can be challenging in the absence of clearly visible or selectable phenotypes. Third, the sgRNA target site must be inactivated after editing to avoid further double-strand break events. We describe here a strategy that addresses these complications by transplanting the protospacer of a highly efficient sgRNA into a gene of interest to render it amenable to genome engineering. This sgRNA targeting the dpy-10 gene generates genome edits at comparatively high frequency. We demonstrate that the transplanted protospacer is cleaved at the same time as the dpy-10 gene. Our strategy generates scarless genome edits because it no longer requires the introduction of mutations in endogenous sgRNA target sites. Modified progeny can be easily identified in the F1 generation, which drastically reduces the number of animals to be tested by PCR or phenotypic analysis. Using this strategy, we reliably generated precise deletion mutants, transcriptional reporters, and translational fusions with epitope tags and fluorescent reporter genes. In particular, we report here the first use of the new red fluorescent protein mScarlet in a multicellular organism. wrmScarlet, a C. elegans-optimized version, dramatically surpassed TagRFP-T by showing an eightfold increase in fluorescence in a direct comparison.

Published
2017
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4. Novel Roles of Caenorhabditis elegans Heterochromatin Protein HP1 and Linker Histone in the Regulation of Innate Immune Gene Expression

Author

Beurton, Flore, Stempor, Przemyslaw, Caron, Matthieu, Appert, Alex, Dong, Yan, Chen, Ron A-j, Cluet, David, Couté, Yohann, Herbette, Marion, Huang, Ni, Polvèche, Hélène, Spichty, Martin, Ahringer, Julie, Kozlowski, L., Robert, Valérie J., Mercier, Marine G., Janczarski, Stéphane, Merlet, Jorge, Garvis, Steve, Ciosk, Rafal, Meister, Peter, Xiao, Yu, Rohner, Sabine, Bodennec, Selena, Hudry, Bruno, Molin, Laurent, Solari, Florence, Gasser, Susan, Simonet, Thomas, Coustham, Vincent, Monier, Karine, Schott, Sonia, Karali, Marianthi, Studencka, M., Konzer, A., Moneron, G., Wenzel, D., Opitz, L., Salinas-Riester, G., Bedet, Cécile, Kruger, M., Hell, S., Wisniewski, J., Schmidt, H., Palladino, Francesca, Schulze, E., Jedrusik-Bode, M., Laboratoire de biologie et modélisation de la cellule (LBMC UMR 5239), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK, The Gurdon Institute, Department of Psychology, Renmin University of China, Etude de la dynamique des protéomes (EDyP), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA), Department of Neurology, Johns Hopkins University (JHU), Reproduction et développement des plantes (RDP), École normale supérieure - Lyon (ENS Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Friedrich Miescher Institute for Biomedical Research (FMI), Novartis Research Foundation, Institute of Clinical Sciences, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College London, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Recherches Avicoles (SRA), Institut National de la Recherche Agronomique (INRA), Laboratoire Joliot Curie, École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS), Telethon Institute for Genetics and Medicine, Telethon Institute, Max-Planck-Institut für Biophysikalische Chemie - Max Planck Institute for Biophysical Chemistry [Göttingen], Max-Planck-Gesellschaft, ESPCI ParisTech, FB Physik, Metallurgie und Werkstoffwissenschaften, Avt. Thermochemie une Mikrokinetik (TECH. UNIV. CLAUSTHAL), Clausthal University of Technology (TU Clausthal), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Transcriptional Activation, Chromosomal Proteins, Non-Histone, Bacillus thuringiensis, Biology, Chromodomain, Histones, 03 medical and health sciences, Histone methylation, Histone H2A, Histone code, Animals, Protein Interaction Domains and Motifs, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Caenorhabditis elegans, Caenorhabditis elegans Proteins, Promoter Regions, Genetic, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Histone binding, Genetics, 0303 health sciences, 030302 biochemistry & molecular biology, EZH2, Cell Biology, Articles, Immunity, Innate, 3. Good health, Gene Expression Regulation, Histone methyltransferase, Host-Pathogen Interactions, Heterochromatin protein 1, Protein Binding
Abstract

Linker histone (H1) and heterochromatin protein 1 (HP1) are essential components of heterochromatin which contribute to the transcriptional repression of genes. It has been shown that the methylation mark of vertebrate histone H1 is specifically recognized by the chromodomain of HP1. However, the exact biological role of linker histone binding to HP1 has not been determined. Here, we investigate the function of the Caenorhabditis elegans H1 variant HIS-24 and the HP1-like proteins HPL-1 and HPL-2 in the cooperative transcriptional regulation of immune-relevant genes. We provide the first evidence that HPL-1 interacts with HIS-24 monomethylated at lysine 14 (HIS-24K14me1) and associates in vivo with promoters of genes involved in antimicrobial response. We also report an increase in overall cellular levels and alterations in the distribution of HIS-24K14me1 after infection with pathogenic bacteria. HIS-24K14me1 localization changes from being mostly nuclear to both nuclear and cytoplasmic in the intestinal cells of infected animals. Our results highlight an antimicrobial role of HIS-24K14me1 and suggest a functional link between epigenetic regulation by an HP1/H1 complex and the innate immune system in C. elegans.

Published
2011
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