المؤلفون: Meléndez García, Rodrigo, Haccard, Olivier, Chesneau, Albert, Narassimprakash, Hemalatha, Roger, Jérôme, Perron, Muriel, Marheineke, Kathrin, Bronchain, Odile

المساهمون: Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

المصدر: EISSN: 2050-084X ; eLife ; https://hal.science/hal-03740290Test ; eLife, 2022, 11, pp.e75741. ⟨10.7554/eLife.75741⟩

مصطلحات موضوعية: DNA replication, Rif1, cell biology, developmental biology, hippo/yap pathway, retinal stem cells, trim-away, Xenopus, MESH: Animals, MESH: DNA Replication, MESH: DNA Replication Timing, MESH: Replication Origin, MESH: S Phase, MESH: Telomere-Binding Proteins, MESH: Xenopus laevis, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences

الوصف: International audience ; In multicellular eukaryotic organisms, the initiation of DNA replication occurs asynchronously throughout S-phase according to a regulated replication timing program. Here, using Xenopus egg extracts, we showed that Yap (Yes-associated protein 1), a downstream effector of the Hippo signalling pathway, is required for the control of DNA replication dynamics. We found that Yap is recruited to chromatin at the start of DNA replication and identified Rif1, a major regulator of the DNA replication timing program, as a novel Yap binding protein. Furthermore, we show that either Yap or Rif1 depletion accelerates DNA replication dynamics by increasing the number of activated replication origins. In Xenopus embryos, using a Trim-Away approach during cleavage stages devoid of transcription, we found that either Yap or Rif1 depletion triggers an acceleration of cell divisions, suggesting a shorter S-phase by alterations of the replication program. Finally, our data show that Rif1 knockdown leads to defects in the partitioning of early versus late replication foci in retinal stem cells, as we previously showed for Yap. Altogether, our findings unveil a non-transcriptional role for Yap in regulating replication dynamics. We propose that Yap and Rif1 function as brakes to control the DNA replication program in early embryos and post-embryonic stem cells.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/35838349; hal-03740290; https://hal.science/hal-03740290Test; https://hal.science/hal-03740290/documentTest; https://hal.science/hal-03740290/file/elife-75741-v2.pdfTest; PUBMED: 35838349; PUBMEDCENTRAL: PMC9328763

الإتاحة: https://doi.org/10.7554/eLife.75741Test
https://hal.science/hal-03740290Test
https://hal.science/hal-03740290/documentTest
https://hal.science/hal-03740290/file/elife-75741-v2.pdfTest

المؤلفون: Ouanounou, Gilles

المساهمون: Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

المصدر: ISSN: 2051-817X ; Physiological Reports ; https://hal.science/hal-03665123Test ; Physiological Reports, 2022, 10 (5), pp.e15200. ⟨10.14814/phy2.15200⟩.

مصطلحات موضوعية: K+ inward rectifier current, barium, blocking foreign cations, cesium, mass action law and dissociation-constant, MESH: Animals, MESH: Cations, MESH: Potassium, MESH: Xenopus laevis, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences

الوصف: International audience ; Cations such as Cs+ and Ba2+ are known to block K+ currents by entering an open channel and binding to the selectivity filter, where they obstruct the pore and block diffusion of the permeant ion. This obstruction is voltage- and K+ -dependent and is relieved by the trans permeant ion flux. The present patch-clamp study on Xenopus muscle cells shows that, unlike the voltage-activated K+ (Kv) channels, blockade of the inward rectifier K+ (Kir) channels by external foreign cations results from the combination of pore obstruction with a new and independent mechanism. This new blockade is independent of the K+ concentrations and flux and acts indiscriminately on both the outward and the inward Kir components. External Cs+ and Ba2+ compete for this blockade with free access to common channel sites. These features suggest that the blocking cations do not need to enter the channel for this new mechanism, and should bind to the extracellular side of the channel. When K+ fluxes are flowing outward, the pore obstruction is relieved for both Kir and Kv currents, and the K+ -independent blockade here described is responsible for a selective Kir inhibition, justifying the use of these external cations as tools in cell physiology studies.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/35274814; hal-03665123; https://hal.science/hal-03665123Test; https://hal.science/hal-03665123/documentTest; https://hal.science/hal-03665123/file/Kir-Ouanounou-PhysRep-2022.pdfTest; PUBMED: 35274814; PUBMEDCENTRAL: PMC8915156

الإتاحة: https://doi.org/10.14814/phy2.15200Test
https://hal.science/hal-03665123Test
https://hal.science/hal-03665123/documentTest
https://hal.science/hal-03665123/file/Kir-Ouanounou-PhysRep-2022.pdfTest

المؤلفون: Maatoug, Sonia, Cheikh, Amani, Khamessi, Oussema, Tabka, Hager, Landoulsi, Zied, Guigonis, Jean-Marie, Diochot, Sylvie, Bendahhou, Saïd, Benkhalifa, Rym

المساهمون: Biomolécules, Venins et Applications Théranostiques Tunis, Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Université de Tunis El Manar (UTM), Laboratoire des Venins et Biomolécules Thérapeutiques - Laboratory of Venoms and Therapeutic Biomolecules (LR11IPT08), Université de Carthage (Tunisie) (UCAR), Transporteurs et Imagerie, Radiothérapie en Oncologie et Mécanismes biologiques des Altérations du Tissu Osseux (TIRO-MATOs UMR E4320), Service Hospitalier Frédéric Joliot (SHFJ), Université Paris-Saclay-Institut des Sciences du Vivant Frédéric JOLIOT (JOLIOT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut des Sciences du Vivant Frédéric JOLIOT (JOLIOT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Université Côte d'Azur (UniCA), Institut de pharmacologie moléculaire et cellulaire (IPMC), Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UniCA), Laboratoire de PhysioMédecine Moléculaire (LP2M), This research was funded by the Tunisian Ministry of Higher Education and Scientific Research: LR11IPT08, and AFM #19928 (to SB).

المصدر: ISSN: 1661-6596.

مصطلحات موضوعية: Kv3.1 channel, Androctonus australis hector venom, open channel blocker, alpha-KTx, MESH: Animals, MESH: Humans, MESH: Molecular Docking Simulation, MESH: Potassium Channel Blockers, MESH: Scorpion Venoms, MESH: Scorpions, MESH: Shaw Potassium Channels, MESH: Xenopus laevis, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology

الوصف: International audience ; The voltage-gated K+ channels Kv3.1 display fast activation and deactivation kinetics and are known to have a crucial contribution to the fast-spiking phenotype of certain neurons. AahG50, as a natural product extracted from Androctonus australis hector venom, inhibits selectively Kv3.1 channels. In the present study, we focused on the biochemical and pharmacological characterization of the component in AahG50 scorpion venom that potently and selectively blocks the Kv3.1 channels. We used a combined optimization through advanced biochemical purification and patch-clamp screening steps to characterize the peptide in AahG50 active on Kv3.1 channels. We described the inhibitory effect of a toxin on Kv3.1 unitary current in black lipid bilayers. In silico, docking experiments are used to study the molecular details of the binding. We identified the first scorpion venom peptide inhibiting Kv3.1 current at 170 nM. This toxin is the alpha-KTx 15.1, which occludes the Kv3.1 channel pore by means of the lysine 27 lateral chain. This study highlights, for the first time, the modulation of the Kv3.1 by alpha-KTx 15.1, which could be an interesting starting compound for developing therapeutic biomolecules against Kv3.1-associated diseases.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/34830172; hal-03455259; https://hal.science/hal-03455259Test; https://hal.science/hal-03455259/documentTest; https://hal.science/hal-03455259/file/ijms2021.pdfTest; PUBMED: 34830172; PUBMEDCENTRAL: PMC8618407

الإتاحة: https://doi.org/10.3390/ijms222212290Test
https://hal.science/hal-03455259Test
https://hal.science/hal-03455259/documentTest
https://hal.science/hal-03455259/file/ijms2021.pdfTest

المؤلفون: Martin, Elodie, Aigrot, Marie-Stephane, Lamari, Foudil, Bachelin, Corinne, Lubetzki, Catherine, Nait Oumesmar, Brahim, Zalc, Bernard, Stankoff, Bruno

المساهمون: Institut du Cerveau = Paris Brain Institute (ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière AP-HP, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

المصدر: ISSN: 2332-7812 ; Neurology Neuroimmunology & Neuroinflammation ; https://hal.sorbonne-universite.fr/hal-03561653Test ; Neurology Neuroimmunology & Neuroinflammation, 2021, 8 (6), pp.e1091. ⟨10.1212/nxi.0000000000001091⟩.

مصطلحات موضوعية: MESH: Animals, Newborn, MESH: Larva, MESH: Mice, Inbred C57BL, Transgenic, MESH: Nitriles, MESH: Oligodendrocyte Precursor Cells, MESH: Oligodendroglia, MESH: Remyelination, MESH: Toluidines, MESH: Xenopus laevis, MESH: Cells, Cultured, MESH: Central Nervous System Diseases, MESH: Cholesterol, MESH: Crotonates, MESH: Demyelinating Diseases, MESH: Disease Models, Animal, MESH: Hydroxybutyrates, MESH: Immunosuppressive Agents, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]

الوصف: International audience ; Background and Objectives To test whether low concentrations of teriflunomide (TF) could promote remyelination, we investigate the effect of TF on oligodendrocyte in culture and on remyelination in vivo in 2 demyelinating models.Methods The effect of TF on oligodendrocyte precursor cell (OPC) proliferation and differentiation was assessed in vitro in glial cultures derived from neonatal mice and confirmed on fluorescence-activated cell sorting–sorted adult OPCs. The levels of the 8,9-unsaturated sterols lanosterol and zymosterol were quantified in TF- and sham-treated cultures. In vivo, TF was administered orally, and remyelination was assessed both in myelin basic protein–GFP-nitroreductase (Mbp:GFP-NTR) transgenic Xenopus laevis demyelinated by metronidazole and in adult mice demyelinated by lysolecithin.Results In cultures, low concentrations of TF down to 10 nM decreased OPC proliferation and increased their differentiation, an effect that was also detected on adult OPCs. Oligodendrocyte differentiation induced by TF was abrogated by the oxidosqualene cyclase inhibitor Ro 48-8071 and was mediated by the accumulation of zymosterol. In the demyelinated tadpole, TF enhanced the regeneration of mature oligodendrocytes up to 2.5-fold. In the mouse demyelinated spinal cord, TF promoted the differentiation of newly generated oligodendrocytes by a factor of 1.7-fold and significantly increased remyelination.Discussion TF enhances zymosterol accumulation in oligodendrocytes and CNS myelin repair, a beneficial off-target effect that should be investigated in patients with multiple sclerosis.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/34642237; hal-03561653; https://hal.sorbonne-universite.fr/hal-03561653Test; https://hal.sorbonne-universite.fr/hal-03561653/documentTest; https://hal.sorbonne-universite.fr/hal-03561653/file/e1091.full.pdfTest; PUBMED: 34642237; PUBMEDCENTRAL: PMC8515201

الإتاحة: https://doi.org/10.1212/nxi.0000000000001091Test
https://hal.sorbonne-universite.fr/hal-03561653Test
https://hal.sorbonne-universite.fr/hal-03561653/documentTest
https://hal.sorbonne-universite.fr/hal-03561653/file/e1091.full.pdfTest

المؤلفون: Gielen, Marc, Barilone, Nathalie, Corringer, Pierre-Jean

المساهمون: Récepteurs Canaux - Channel Receptors, Institut Pasteur Paris (IP)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Financial support by the Fondation de la Recherche Médicale (grant “Équipe FRM” DEQ20140329497 to P.-J.C.) and the European Commission Research Executive Agency (Marie Sklodowska-Curie Action, Individual Fellowship 659371 to M.G., ERC Advanced Grant GA788974 Dynacotine to P.-J.C.). M.G. is grateful to the Fondation Bettencourt Schueller for their support., European Project: 659371,H2020,H2020-MSCA-IF-2014,nAChR PAM-to-gate(2015), European Project: 788974,H2020

المصدر: ISSN: 2041-1723.

مصطلحات موضوعية: MESH: Animals, MESH: Computer Simulation, MESH: Protein Conformation, MESH: Protein Subunits, MESH: Receptors, GABA-A, MESH: Synaptic Transmission, MESH: Xenopus laevis, MESH: Ion Channels, MESH: Ion Transport, MESH: Kinetics, MESH: Models, Molecular, MESH: Molecular Conformation, MESH: Mutation, MESH: Nervous System, MESH: Oocytes, [SDV]Life Sciences [q-bio]

الوصف: International audience ; GABAA receptors mediate most inhibitory synaptic transmission in the brain of vertebrates. Following GABA binding and fast activation, these receptors undergo a slower desensitization, whose conformational pathway 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.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/33097732; info:eu-repo/grantAgreement//659371/EU/Gating mechanism and pharmacological modulation of nicotinic acetylcholine receptors/nAChR PAM-to-gate; info:eu-repo/grantAgreement//788974/EU/Signal transduction and allosteric modulation of nicotinic acetylcholine receptors:from ion channel electrophysiology to atomic 3D structures/Dynacotine; pasteur-03088067; https://pasteur.hal.science/pasteur-03088067Test; https://pasteur.hal.science/pasteur-03088067/documentTest; https://pasteur.hal.science/pasteur-03088067/file/Gielen.%202020.pdfTest; PUBMED: 33097732; PUBMEDCENTRAL: PMC7585415

الإتاحة: https://doi.org/10.1038/s41467-020-19218-6Test
https://pasteur.hal.science/pasteur-03088067Test
https://pasteur.hal.science/pasteur-03088067/documentTest
https://pasteur.hal.science/pasteur-03088067/file/Gielen.%202020.pdfTest

المؤلفون: Parain, Karine, Donval, Alicia, Chesneau, Albert, Lun, Jing Xian, Borday, Caroline, Perron, Muriel

المساهمون: Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

المصدر: ISSN: 1940-087X.

مصطلحات موضوعية: MESH: Animals, MESH: Xenopus laevis, MESH: Larva, MESH: Retina, Genetically Modified, MESH: Retinitis Pigmentosa, MESH: Mammals, [SDV]Life Sciences [q-bio]

الوصف: Retinal neurodegenerative diseases are the leading causes of blindness. Among numerous therapeutic strategies being explored, stimulating self-repair recently emerged as particularly appealing. A cellular source of interest for retinal repair is the Müller glial cell, which harbors stem cell potential and an extraordinary regenerative capacity in anamniotes. This potential is, however, very limited in mammals. Studying the molecular mechanisms underlying retinal regeneration in animal models with regenerative capabilities should provide insights into how to unlock the latent ability of mammalian Müller cells to regenerate the retina. This is a key step for the development of therapeutic strategies in regenerative medicine. To this aim, we developed several retinal injury paradigms in Xenopus: a mechanical retinal injury, a transgenic line allowing for nitroreductase-mediated photoreceptor conditional ablation, a retinitis pigmentosa model based on CRISPR/Cas9-mediated rhodopsin knockout, and a cytotoxic model driven by intraocular CoCl2 injections. Highlighting their advantages and disadvantages, we describe here this series of protocols that generate various degenerative conditions and allow the study of retinal regeneration in Xenopus.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/37902314; hal-04308410; https://hal.science/hal-04308410Test; https://hal.science/hal-04308410/documentTest; https://hal.science/hal-04308410/file/jove-protocol-65771generating-retinal-injury-models.pdfTest; PUBMED: 37902314

الإتاحة: https://doi.org/10.3791/65771Test
https://hal.science/hal-04308410Test
https://hal.science/hal-04308410/documentTest
https://hal.science/hal-04308410/file/jove-protocol-65771generating-retinal-injury-models.pdfTest

المؤلفون: Haccard, Olivier, Ciardo, Diletta, Narrissamprakash, Hemalatha, Bronchain, Odile, Kumagai, Akiko, Dunphy, William, Goldar, Arach, Marheineke, Kathrin

المساهمون: Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125

المصدر: ISSN: 2399-3642 ; Communications Biology ; https://hal.science/hal-04223559Test ; Communications Biology, 2023, 6 (1), pp.788. ⟨10.1038/s42003-023-05172-8⟩.

مصطلحات موضوعية: MESH: Animals, MESH: Cell Cycle, MESH: Cell Cycle Proteins, MESH: Chromatin, MESH: Replication Origin, MESH: Xenopus laevis, [SDV]Life Sciences [q-bio]

الوصف: Metazoan genomes are duplicated by the coordinated activation of clusters of replication origins at different times during S phase, but the underlying mechanisms of this temporal program remain unclear during early development. Rif1, a key replication timing factor, inhibits origin firing by recruiting protein phosphatase 1 (PP1) to chromatin counteracting S phase kinases. We have previously described that Rif1 depletion accelerates early Xenopus laevis embryonic cell cycles. Here, we find that in the absence of Rif1, patterns of replication foci change along with the acceleration of replication cluster activation. However, initiations increase only moderately inside active clusters. Our numerical simulations suggest that the absence of Rif1 compresses the temporal program towards more homogeneity and increases the availability of limiting initiation factors. We experimentally demonstrate that Rif1 depletion increases the chromatin-binding of the S phase kinase Cdc7/Drf1, the firing factors Treslin, MTBP, Cdc45, RecQL4, and the phosphorylation of both Treslin and MTBP. We show that Rif1 globally, but not locally, restrains the replication program in early embryos, possibly by inhibiting or excluding replication factors from chromatin.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/37516798; hal-04223559; https://hal.science/hal-04223559Test; PUBMED: 37516798; PUBMEDCENTRAL: PMC10387115

الإتاحة: https://doi.org/10.1038/s42003-023-05172-8Test
https://hal.science/hal-04223559Test

المؤلفون: Vivaudou, Michel, Todorov, Zlatomir, Reyes-Mejia, Gina Catalina, Moreau, Christophe J

المساهمون: Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-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), ANR-11-RPIB-0022,VenomPicoScreen,Découverte de principes actifs à partir de venins en utilisant des bicouches artificielles miniaturisées(2011), ANR-11-LABX-0015,ICST,Canaux ioniques d'intérêt thérapeutique(2011), European Project: NIH

المصدر: Membrane Protein Structure and Function Characterization: Methods and Protocols, Methods in Molecular Biology ; https://hal.science/hal-02007728Test ; Membrane Protein Structure and Function Characterization: Methods and Protocols, Methods in Molecular Biology, 1635, Jean-Jacques Lacapere, pp.283-301, 2017, ⟨10.1007/978-1-4939-7151-0_15⟩

مصطلحات موضوعية: G-protein-coupled receptor, Ion-channel-coupled receptor, Potassium channel, Robot, Two-electrode voltage clamp, Xenopus oocyte, MESH: Animals, MESH: Automation, Laboratory, MESH: Xenopus Proteins, MESH: Xenopus laevis, MESH: Cell Membrane, MESH: Electrophysiological Phenomena, MESH: Female, MESH: G Protein-Coupled Inwardly-Rectifying Potassium Channels, MESH: Oocytes, MESH: Receptors, G-Protein-Coupled, MESH: Signal Transduction, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM]

الوصف: International audience ; G-protein-coupled receptors (GPCR) are the most widely used system of communication used by cells. They sense external signals and translate them into intracellular signals. The information is carried mechanically across the cell membrane, without perturbing its integrity. Agonist binding on the extracellular side causes a change in receptor conformation which propagates to the intracellular side and causes release of activated G-proteins, the first messengers of a variety of signaling cascades.Permitting access to powerful electrophysiological techniques, ion channels can be employed to monitor precisely the most proximal steps of GPCR signaling, receptor conformational changes, and G-protein release. The former is achieved by physical attachment of a potassium channel to the GPCR to create an Ion-Channel Coupled Receptor (ICCR). The latter is based on the use of G-protein-regulated potassium channels (GIRK). We describe here how these two systems may be used in the Xenopus oocyte heterologous system with a robotic system for increased throughput.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/28755375; hal-02007728; https://hal.science/hal-02007728Test; PUBMED: 28755375

الإتاحة: https://doi.org/10.1007/978-1-4939-7151-0_15Test
https://hal.science/hal-02007728Test

المؤلفون: Silbernagel, Nicole, Walecki, Magdalena, Schäfer, Martin K-H, Kessler, Mirjam, Zobeiri, Mehrnoush, Rinné, Susanne, Kiper, Aytug, Komadowski, Marlene, Vowinkel, Kirsty, Wemhöner, Konstantin, Fortmüller, Lisa, Schewe, Marcus, Dolga, Amalia, Scekic-Zahirovic, Jelena, Matschke, Lina, Culmsee, Carsten, Baukrowitz, Thomas, Monassier, Laurent, Ullrich, Nina, Dupuis, Luc, Just, Steffen, Budde, Thomas, Fabritz, Larissa, Decher, Niels

المساهمون: Philipps Universität Marburg = Philipps University of Marburg, Universitätsklinikum Ulm - University Hospital of Ulm, Westfälische Wilhelms-Universität Münster = University of Münster (WWU), University Hospital Münster - Universitaetsklinikum Muenster Germany (UKM), Christian-Albrechts-Universität zu Kiel = Christian-Albrechts University of Kiel = Université Christian-Albrechts de Kiel (CAU), Laboratoire de pharmacologie et toxicologie neurocardiovasculaire (LPTNC), Université de Strasbourg (UNISTRA), Universität Heidelberg Heidelberg = Heidelberg University, Mécanismes Centraux et Périphériques de la Neurodégénérescence (MCPN), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM), University Hospitals Birmingham Birmingham, Royaume-Uni, University of Birmingham Birmingham

المصدر: ISSN: 0892-6638.

مصطلحات موضوعية: ALS, HCN channels, cardiac arrhythmia, MESH: Animals, MESH: Carrier Proteins, MESH: Membrane Proteins, MESH: Mice, Knockout, MESH: Neurons, MESH: Pacemaker, Artificial, MESH: Rats, Sprague-Dawley, MESH: Vesicular Transport Proteins, MESH: Xenopus laevis, MESH: Zebrafish, MESH: Embryo, Nonmammalian, MESH: Female, MESH: HeLa Cells, MESH: Heart, MESH: Humans, MESH: Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels, MESH: Ion Channel Gating, [SDV]Life Sciences [q-bio]

الوصف: International audience ; Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels encode neuronal and cardiac pacemaker currents. The composition of pacemaker channel complexes in different tissues is poorly understood, and the presence of additional HCN modulating subunits was speculated. Here we show that vesicle-associated membrane protein-associated protein B (VAPB), previously associated with a familial form of amyotrophic lateral sclerosis 8, is an essential HCN1 and HCN2 modulator. VAPB significantly increases HCN2 currents and surface expression and has a major influence on the dendritic neuronal distribution of HCN2. Severe cardiac bradycardias in VAPB-deficient zebrafish and VAPB-/- mice highlight that VAPB physiologically serves to increase cardiac pacemaker currents. An altered T-wave morphology observed in the ECGs of VAPB-/- mice supports the recently proposed role of HCN channels for ventricular repolarization. The critical function of VAPB in native pacemaker channel complexes will be relevant for our understanding of cardiac arrhythmias and epilepsies, and provides an unexpected link between these diseases and amyotrophic lateral sclerosis.-Silbernagel, N., Walecki, M., Schäfer, M.-K. H., Kessler, M., Zobeiri, M., Rinné, S., Kiper, A. K., Komadowski, M. A., Vowinkel, K. S., Wemhöner, K., Fortmüller, L., Schewe, M., Dolga, A. M., Scekic-Zahirovic, J., Matschke, L. A., Culmsee, C., Baukrowitz, T., Monassier, L., Ullrich, N. D., Dupuis, L., Just, S., Budde, T., Fabritz, L., Decher, N. The VAMP-associated protein VAPB is required for cardiac and neuronal pacemaker channel function.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/29879376; inserm-03376145; https://inserm.hal.science/inserm-03376145Test; https://inserm.hal.science/inserm-03376145/documentTest; https://inserm.hal.science/inserm-03376145/file/fj.201800246R.pdfTest; PUBMED: 29879376; PUBMEDCENTRAL: PMC6629115

الإتاحة: https://doi.org/10.1096/fj.201800246RTest
https://inserm.hal.science/inserm-03376145Test
https://inserm.hal.science/inserm-03376145/documentTest
https://inserm.hal.science/inserm-03376145/file/fj.201800246R.pdfTest

المؤلفون: Olivier Haccard, Rodrigo Meléndez García, Albert Chesneau, Hemalatha Narassimprakash, Jérôme Roger, Muriel Perron, Kathrin Marheineke, Odile Bronchain

المساهمون: Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

المصدر: eLife
eLife, 2022, 11, pp.e75741. ⟨10.7554/eLife.75741⟩

مصطلحات موضوعية: trim-away, General Immunology and Microbiology, [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior, General Neuroscience, Xenopus, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, hippo/yap pathway, MESH: S Phase, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences, MESH: DNA Replication, General Medicine, DNA replication, General Biochemistry, Genetics and Molecular Biology, MESH: Telomere-Binding Proteins, developmental biology, retinal stem cells, Rif1, MESH: Xenopus laevis, cell biology, MESH: Replication Origin, MESH: Animals, MESH: DNA Replication Timing

الوصف: In multicellular eukaryotic organisms, the initiation of DNA replication occurs asynchronously throughout S-phase according to a regulated replication timing program. Here, using Xenopus egg extracts, we showed that Yap (Yes-associated protein 1), a downstream effector of the Hippo signalling pathway, is required for the control of DNA replication dynamics. We found that Yap is recruited to chromatin at the start of DNA replication and identified Rif1, a major regulator of the DNA replication timing program, as a novel Yap binding protein. Furthermore, we show that either Yap or Rif1 depletion accelerates DNA replication dynamics by increasing the number of activated replication origins. In Xenopus embryos, using a Trim-Away approach during cleavage stages devoid of transcription, we found that either Yap or Rif1 depletion triggers an acceleration of cell divisions, suggesting a shorter S-phase by alterations of the replication program. Finally, our data show that Rif1 knockdown leads to defects in the partitioning of early versus late replication foci in retinal stem cells, as we previously showed for Yap. Altogether, our findings unveil a non-transcriptional role for Yap in regulating replication dynamics. We propose that Yap and Rif1 function as brakes to control the DNA replication program in early embryos and post-embryonic stem cells.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d5cc4245ce755896c70c90a49300395aTest
https://hal.science/hal-03740290/file/elife-75741-v2.pdfTest