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Yue Z, Li Y, Yu B, Xu Y, Chen L, Chitturi J, Meng J, Wang Y, Tian Y, Mouridi SE, Zhang C, Zhen M, Boulin T, Gao S. A leak K + channel TWK-40 sustains the rhythmic motor program. PNAS NEXUS 2024; 3:pgae234. [PMID: 38957449 PMCID: PMC11217676 DOI: 10.1093/pnasnexus/pgae234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024]
Abstract
Leak potassium (K+) currents, conducted by two-pore domain K+ (K2P) channels, are critical for the stabilization of the membrane potential. The effect of K2P channels on motor rhythm remains enigmatic. We show here that the K2P TWK-40 contributes to the rhythmic defecation motor program (DMP) in Caenorhabditis elegans. Disrupting TWK-40 suppresses the expulsion defects of nlp-40 and aex-2 mutants. By contrast, a gain-of-function (gf) mutant of twk-40 significantly reduces the expulsion frequency per DMP cycle. In situ whole-cell patch clamping demonstrates that TWK-40 forms an outward current that hyperpolarize the resting membrane potential of dorsorectal ganglion ventral process B (DVB), an excitatory GABAergic motor neuron that activates expulsion muscle contraction. In addition, TWK-40 substantially contributes to the rhythmic activity of DVB. Specifically, DVB Ca2+ oscillations exhibit obvious defects in loss-of-function (lf) mutant of twk-40. Expression of TWK-40(gf) in DVB recapitulates the expulsion deficiency of the twk-40(gf) mutant, and inhibits DVB Ca2+ oscillations in both wild-type and twk-40(lf) animals. Moreover, DVB innervated enteric muscles also exhibit rhythmic Ca2+ defects in twk-40 mutants. In summary, these findings establish TWK-40 as a crucial neuronal stabilizer of DMP, linking leak K2P channels with rhythmic motor activity.
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Affiliation(s)
- Zhongpu Yue
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bin Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yueqing Xu
- College of Biomedical Engineering, South-Central University for Nationalities, Wuhan 430074, China
| | - Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jyothsna Chitturi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Jun Meng
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Ying Wang
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Yuhang Tian
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Sonia El Mouridi
- Univ Lyon, Université Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 23955–6900, Kingdom of Saudi Arabia
| | - Cuntai Zhang
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Thomas Boulin
- Univ Lyon, Université Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Buckley M, Jacob WP, Bortey L, McClain M, Ritter AL, Godfrey A, Munneke AS, Ramachandran S, Kenis S, Kolnik JC, Olofsson S, Adkins R, Kutoloski T, Rademacher L, Heinecke O, Alva A, Beets I, Francis MM, Kowalski JR. Cell non-autonomous signaling through the conserved C. elegans glycopeptide hormone receptor FSHR-1 regulates cholinergic neurotransmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.578699. [PMID: 38405708 PMCID: PMC10888917 DOI: 10.1101/2024.02.10.578699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored. Glycoproteins and their G protein-coupled receptors (GPCRs) are well-established orchestrators of multi-tissue signaling events that govern diverse physiological processes through both cell-autonomous and cell non-autonomous regulation. Here, we show that follicle stimulating hormone receptor, FSHR-1, the sole Caenorhabditis elegans ortholog of mammalian glycoprotein hormone GPCRs, is important for cell non-autonomous modulation of synaptic transmission. Inhibition of fshr-1 expression reduces muscle contraction and leads to synaptic vesicle accumulation in cholinergic motor neurons. The neuromuscular and locomotor defects in fshr-1 loss-of-function mutants are associated with an underlying accumulation of synaptic vesicles, build-up of the synaptic vesicle priming factor UNC-10/RIM, and decreased synaptic vesicle release from cholinergic motor neurons. Restoration of FSHR-1 to the intestine is sufficient to restore neuromuscular activity and synaptic vesicle localization to fshr-1- deficient animals. Intestine-specific knockdown of FSHR-1 reduces neuromuscular function, indicating FSHR-1 is both necessary and sufficient in the intestine for its neuromuscular effects. Re-expression of FSHR-1 in other sites of endogenous expression, including glial cells and neurons, also restored some neuromuscular deficits, indicating potential cross-tissue regulation from these tissues as well. Genetic interaction studies provide evidence that downstream effectors gsa-1 / Gα S , acy-1 /adenylyl cyclase and sphk-1/ sphingosine kinase and glycoprotein hormone subunit orthologs, GPLA-1/GPA2 and GPLB-1/GPB5, are important for FSHR-1 modulation of the NMJ. Together, our results demonstrate that FSHR-1 modulation directs inter-tissue signaling systems, which promote synaptic vesicle release at neuromuscular synapses.
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Choi U, Hu M, Zhang Q, Sieburth D. The head mesodermal cell couples FMRFamide neuropeptide signaling with rhythmic muscle contraction in C. elegans. Nat Commun 2023; 14:4218. [PMID: 37452027 PMCID: PMC10349088 DOI: 10.1038/s41467-023-39955-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 07/06/2023] [Indexed: 07/18/2023] Open
Abstract
FMRFamides are evolutionarily conserved neuropeptides that play critical roles in behavior, energy balance, and reproduction. Here, we show that FMRFamide signaling from the nervous system is critical for the rhythmic activation of a single cell of previously unknown function, the head mesodermal cell (hmc) in C. elegans. Behavioral, calcium imaging, and genetic studies reveal that release of the FLP-22 neuropeptide from the AVL neuron in response to pacemaker signaling activates hmc every 50 s through an frpr-17 G protein-coupled receptor (GPCR) and a protein kinase A signaling cascade in hmc. hmc activation results in muscle contraction through coupling by gap junctions composed of UNC-9/Innexin. hmc activation is inhibited by the neuronal release of a second FMRFamide-like neuropeptide, FLP-9, which functions through its GPCR, frpr-21, in hmc. This study reveals a function for two opposing FMRFamide signaling pathways in controlling the rhythmic activation of a target cell through volume transmission.
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Affiliation(s)
- Ukjin Choi
- DSR graduate program, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Mingxi Hu
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Qixin Zhang
- MPHY program, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Derek Sieburth
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
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4
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Lin TA, How CM, Yen PL, Liao VHC. Sulfate-modified nanosized polystyrene impairs memory by inhibiting ionotropic glutamate receptors and the cAMP-response element binding protein (CREB) pathway in Caenorhabditis elegans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 875:162404. [PMID: 36868277 DOI: 10.1016/j.scitotenv.2023.162404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/16/2023] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
Nanoplastic contamination is an emerging environmental concern worldwide. In particular, sulfate anionic surfactants often appear along with nanosized plastic particles in personal care products, suggesting that sulfate-modified nanosized polystyrene (S-NP) may occur, remain, and spread into the environment. However, whether S-NP adversely affects learning and memory is unknown. In this study, we used a positive butanone training protocol to evaluate the effects of S-NP exposure on short-term associative memory (STAM) and long-term associative memory (LTAM) in Caenorhabditis elegans. We observed that long-term S-NP exposure impairs both STAM and LTAM in C. elegans. We also observed that mutations in the glr-1, nmr-1, acy-1, unc-43, and crh-1 genes eliminated the STAM and LTAM impairment induced by S-NP, and the mRNA levels of these genes were also decreased upon S-NP exposure. These genes encode ionotropic glutamate receptors (iGluRs), cyclic adenosine monophosphate (cAMP)/Ca2+ signaling proteins, and cAMP-response element binding protein (CREB)/CRH-1 signaling proteins. Moreover, S-NP exposure inhibited the expression of the CREB-dependent LTAM genes nid-1, ptr-15, and unc-86. Our findings provide new insights into long-term S-NP exposure and the impairment of STAM and LTAM, which involve the highly conserved iGluRs and CRH-1/CREB signaling pathways.
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Affiliation(s)
- Ting-An Lin
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Chun Ming How
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Pei-Ling Yen
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan.
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5
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Pannone L, Muto V, Nardecchia F, Di Rocco M, Marchei E, Tosato F, Petrini S, Onorato G, Lanza E, Bertuccini L, Manti F, Folli V, Galosi S, Di Schiavi E, Leuzzi V, Tartaglia M, Martinelli S. The recurrent pathogenic Pro890Leu substitution in CLTC causes a generalized defect in synaptic transmission in Caenorhabditis elegans. Front Mol Neurosci 2023; 16:1170061. [PMID: 37324589 PMCID: PMC10264582 DOI: 10.3389/fnmol.2023.1170061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
De novo CLTC mutations underlie a spectrum of early-onset neurodevelopmental phenotypes having developmental delay/intellectual disability (ID), epilepsy, and movement disorders (MD) as major clinical features. CLTC encodes the widely expressed heavy polypeptide of clathrin, a major component of the coated vesicles mediating endocytosis, intracellular trafficking, and synaptic vesicle recycling. The underlying pathogenic mechanism is largely unknown. Here, we assessed the functional impact of the recurrent c.2669C > T (p.P890L) substitution, which is associated with a relatively mild ID/MD phenotype. Primary fibroblasts endogenously expressing the mutated protein show reduced transferrin uptake compared to fibroblast lines obtained from three unrelated healthy donors, suggesting defective clathrin-mediated endocytosis. In vitro studies also reveal a block in cell cycle transition from G0/G1 to the S phase in patient's cells compared to control cells. To demonstrate the causative role of the p.P890L substitution, the pathogenic missense change was introduced at the orthologous position of the Caenorhabditis elegans gene, chc-1 (p.P892L), via CRISPR/Cas9. The resulting homozygous gene-edited strain displays resistance to aldicarb and hypersensitivity to PTZ, indicating defective release of acetylcholine and GABA by ventral cord motor neurons. Consistently, mutant animals show synaptic vesicle depletion at the sublateral nerve cords, and slightly defective dopamine signaling, highlighting a generalized deficit in synaptic transmission. This defective release of neurotransmitters is associated with their secondary accumulation at the presynaptic membrane. Automated analysis of C. elegans locomotion indicates that chc-1 mutants move slower than their isogenic controls and display defective synaptic plasticity. Phenotypic profiling of chc-1 (+/P892L) heterozygous animals and transgenic overexpression experiments document a mild dominant-negative behavior for the mutant allele. Finally, a more severe phenotype resembling that of chc-1 null mutants is observed in animals harboring the c.3146 T > C substitution (p.L1049P), homologs of the pathogenic c.3140 T > C (p.L1047P) change associated with a severe epileptic phenotype. Overall, our findings provide novel insights into disease mechanisms and genotype-phenotype correlations of CLTC-related disorders.
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Affiliation(s)
- Luca Pannone
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Valentina Muto
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | | | - Martina Di Rocco
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Emilia Marchei
- National Centre on Addiction and Doping, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Tosato
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Giada Onorato
- Institute of Biosciences and Bioresources, National Research Council, Naples, Italy
- Department of Environmental, Biological and Pharmaceutical Science and Technologies, Università degli Studi della Campania “Luigi Vanvitelli”, Caserta, Italy
| | - Enrico Lanza
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
- D-Tails s.r.l., Rome, Italy
| | | | - Filippo Manti
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Viola Folli
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
- D-Tails s.r.l., Rome, Italy
| | - Serena Galosi
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Elia Di Schiavi
- Institute of Biosciences and Bioresources, National Research Council, Naples, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
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6
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Bergs ACF, Liewald JF, Rodriguez-Rozada S, Liu Q, Wirt C, Bessel A, Zeitzschel N, Durmaz H, Nozownik A, Dill H, Jospin M, Vierock J, Bargmann CI, Hegemann P, Wiegert JS, Gottschalk A. All-optical closed-loop voltage clamp for precise control of muscles and neurons in live animals. Nat Commun 2023; 14:1939. [PMID: 37024493 PMCID: PMC10079764 DOI: 10.1038/s41467-023-37622-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
Excitable cells can be stimulated or inhibited by optogenetics. Since optogenetic actuation regimes are often static, neurons and circuits can quickly adapt, allowing perturbation, but not true control. Hence, we established an optogenetic voltage-clamp (OVC). The voltage-indicator QuasAr2 provides information for fast, closed-loop optical feedback to the bidirectional optogenetic actuator BiPOLES. Voltage-dependent fluorescence is held within tight margins, thus clamping the cell to distinct potentials. We established the OVC in muscles and neurons of Caenorhabditis elegans, and transferred it to rat hippocampal neurons in slice culture. Fluorescence signals were calibrated to electrically measured potentials, and wavelengths to currents, enabling to determine optical I/V-relationships. The OVC reports on homeostatically altered cellular physiology in mutants and on Ca2+-channel properties, and can dynamically clamp spiking in C. elegans. Combining non-invasive imaging with control capabilities of electrophysiology, the OVC facilitates high-throughput, contact-less electrophysiology in individual cells and paves the way for true optogenetic control in behaving animals.
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Affiliation(s)
- Amelie C F Bergs
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Silvia Rodriguez-Rozada
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Qiang Liu
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY, 10065, USA
- Department of Neuroscience, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China
| | - Christin Wirt
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Artur Bessel
- Independent Researcher, Melatener Strasse 93, 52074, Aachen, Germany
| | - Nadja Zeitzschel
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Hilal Durmaz
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Adrianna Nozownik
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Holger Dill
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Maëlle Jospin
- Université Claude Bernard Lyon 1, Institut NeuroMyoGène, 8 Avenue Rockefeller, 69008, Lyon, France
| | - Johannes Vierock
- Institute for Biology, Experimental Biophysics, Humboldt University, 10115, Berlin, Germany
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY, 10065, USA
- Chan Zuckerberg Initiative, Palo Alto, CA, USA
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt University, 10115, Berlin, Germany
| | - J Simon Wiegert
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
- Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Strasse 13-17, 68167, Mannheim, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany.
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7
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Quévillon Huberdeau M, Shah VN, Nahar S, Neumeier J, Houle F, Bruckmann A, Gypas F, Nakanishi K, Großhans H, Meister G, Simard MJ. A specific type of Argonaute phosphorylation regulates binding to microRNAs during C. elegans development. Cell Rep 2022; 41:111822. [PMID: 36516777 PMCID: PMC10436268 DOI: 10.1016/j.celrep.2022.111822] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 09/22/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Argonaute proteins are at the core of the microRNA-mediated gene silencing pathway essential for animals. In C. elegans, the microRNA-specific Argonautes ALG-1 and ALG-2 regulate multiple processes required for proper animal developmental timing and viability. Here we identified a phosphorylation site on ALG-1 that modulates microRNA association. Mutating ALG-1 serine 642 into a phospho-mimicking residue impairs microRNA binding and causes embryonic lethality and post-embryonic phenotypes that are consistent with alteration of microRNA functions. Monitoring microRNA levels in alg-1 phosphorylation mutant animals shows that microRNA passenger strands increase in abundance but are not preferentially loaded into ALG-1, indicating that the miRNA binding defects could lead to microRNA duplex accumulation. Our genetic and biochemical experiments support protein kinase A (PKA) KIN-1 as the putative kinase that phosphorylates ALG-1 serine 642. Our data indicate that PKA triggers ALG-1 phosphorylation to regulate its microRNA association during C. elegans development.
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Affiliation(s)
- Miguel Quévillon Huberdeau
- CHU de Québec-Université Laval Research Center (Oncology Division), Québec City, QC G1R 3S3, Canada; Université Laval Cancer Research Centre, Québec City, QC G1R 3S3, Canada
| | - Vivek Nilesh Shah
- CHU de Québec-Université Laval Research Center (Oncology Division), Québec City, QC G1R 3S3, Canada; Université Laval Cancer Research Centre, Québec City, QC G1R 3S3, Canada
| | - Smita Nahar
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Julia Neumeier
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, 93053 Regensburg, Germany
| | - François Houle
- CHU de Québec-Université Laval Research Center (Oncology Division), Québec City, QC G1R 3S3, Canada; Université Laval Cancer Research Centre, Québec City, QC G1R 3S3, Canada
| | - Astrid Bruckmann
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, 93053 Regensburg, Germany
| | - Foivos Gypas
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Kotaro Nakanishi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, Columbus, OH 43210, USA
| | - Helge Großhans
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; University of Basel, 4056 Basel, Switzerland
| | - Gunter Meister
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, 93053 Regensburg, Germany
| | - Martin J Simard
- CHU de Québec-Université Laval Research Center (Oncology Division), Québec City, QC G1R 3S3, Canada; Université Laval Cancer Research Centre, Québec City, QC G1R 3S3, Canada.
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8
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Functional Insights into Protein Kinase A (PKA) Signaling from C. elegans. LIFE (BASEL, SWITZERLAND) 2022; 12:life12111878. [PMID: 36431013 PMCID: PMC9692727 DOI: 10.3390/life12111878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/04/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022]
Abstract
Protein kinase A (PKA), which regulates a diverse set of biological functions downstream of cyclic AMP (cAMP), is a tetramer consisting of two catalytic subunits (PKA-C) and two regulatory subunits (PKA-R). When cAMP binds the PKA-R subunits, the PKA-C subunits are released and interact with downstream effectors. In Caenorhabditis elegans (C. elegans), PKA-C and PKA-R are encoded by kin-1 and kin-2, respectively. This review focuses on the contributions of work in C. elegans to our understanding of the many roles of PKA, including contractility and oocyte maturation in the reproductive system, lipid metabolism, physiology, mitochondrial function and lifespan, and a wide variety of behaviors. C. elegans provides a powerful genetic platform for understanding how this kinase can regulate an astounding variety of physiological responses.
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9
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Shi Y, Qin L, Wu M, Zheng J, Xie T, Shao Z. Gut neuroendocrine signaling regulates synaptic assembly in C. elegans. EMBO Rep 2022; 23:e53267. [PMID: 35748387 DOI: 10.15252/embr.202153267] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 11/09/2022] Open
Abstract
Synaptic connections are essential to build a functional brain. How synapses are formed during development is a fundamental question in neuroscience. Recent studies provided evidence that the gut plays an important role in neuronal development through processing signals derived from gut microbes or nutrients. Defects in gut-brain communication can lead to various neurological disorders. Although the roles of the gut in communicating signals from its internal environment to the brain are well known, it remains unclear whether the gut plays a genetically encoded role in neuronal development. Using C. elegans as a model, we uncover that a Wnt-endocrine signaling pathway in the gut regulates synaptic development in the brain. A canonical Wnt signaling pathway promotes synapse formation through regulating the expression of the neuropeptides encoding gene nlp-40 in the gut, which functions through the neuronally expressed GPCR/AEX-2 receptor during development. Wnt-NLP-40-AEX-2 signaling likely acts to modulate neuronal activity. Our study reveals a genetic role of the gut in synaptic development and identifies a novel contribution of the gut-brain axis.
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Affiliation(s)
- Yanjun Shi
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lu Qin
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Mengting Wu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Junyu Zheng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Tao Xie
- Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhiyong Shao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
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10
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Jiang J, Su Y, Zhang R, Li H, Tao L, Liu Q. C. elegans enteric motor neurons fire synchronized action potentials underlying the defecation motor program. Nat Commun 2022; 13:2783. [PMID: 35589790 PMCID: PMC9120479 DOI: 10.1038/s41467-022-30452-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
C. elegans neurons were thought to be non-spiking until our recent discovery of action potentials in the sensory neuron AWA; however, the extent to which the C. elegans nervous system relies on analog or digital coding is unclear. Here we show that the enteric motor neurons AVL and DVB fire synchronous all-or-none calcium-mediated action potentials following the intestinal pacemaker during the rhythmic C. elegans defecation behavior. AVL fires unusual compound action potentials with each depolarizing calcium spike mediated by UNC-2 followed by a hyperpolarizing potassium spike mediated by a repolarization-activated potassium channel EXP-2. Simultaneous behavior tracking and imaging in free-moving animals suggest that action potentials initiated in AVL propagate along its axon to activate precisely timed DVB action potentials through the INX-1 gap junction. This work identifies a novel circuit of spiking neurons in C. elegans that uses digital coding for long-distance communication and temporal synchronization underlying reliable behavioral rhythm.
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Affiliation(s)
- Jingyuan Jiang
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Yifan Su
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Ruilin Zhang
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, 100871, China
- Yuanpei College, Peking University, Beijing, 100871, China
| | - Haiwen Li
- LMAM, School of Mathematical Sciences, Peking University, Beijing, 100871, China
| | - Louis Tao
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, 100871, China
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Qiang Liu
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY, 10065, USA.
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong SAR.
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11
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Choi U, Wang H, Hu M, Kim S, Sieburth D. Presynaptic coupling by electrical synapses coordinates a rhythmic behavior by synchronizing the activities of a neuron pair. Proc Natl Acad Sci U S A 2021; 118:e2022599118. [PMID: 33972428 PMCID: PMC8157971 DOI: 10.1073/pnas.2022599118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Electrical synapses are specialized structures that mediate the flow of electrical currents between neurons and have well known roles in synchronizing the activities of neuronal populations, both by mediating the current transfer from more active to less active neurons and by shunting currents from active neurons to their less active neighbors. However, how these positive and negative functions of electrical synapses are coordinated to shape rhythmic synaptic outputs and behavior is not well understood. Here, using a combination of genetics, behavioral analysis, and live calcium imaging in Caenorhabditis elegans, we show that electrical synapses formed by the gap junction protein INX-1/innexin couple the presynaptic terminals of a pair of motor neurons (AVL and DVB) to synchronize their activation in response to a pacemaker signal. Live calcium imaging reveals that inx-1/innexin mutations lead to asynchronous activation of AVL and DVB, due, in part, to loss of AVL-mediated activation of DVB by the pacemaker. In addition, loss of inx-1 leads to the ectopic activation of DVB at inappropriate times during the cycle through the activation of the L-type voltage-gated calcium channel EGL-19. We propose that electrical synapses between AVL and DVB presynaptic terminals function to ensure the precise and robust execution of a specific step in a rhythmic behavior by both synchronizing the activities of presynaptic terminals in response to pacemaker signaling and by inhibiting their activation in between cycles when pacemaker signaling is low.
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Affiliation(s)
- Ukjin Choi
- Development, Stem Cell, and Regenerative Medicine Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033
| | - Han Wang
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033
| | - Mingxi Hu
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033
| | - Sungjin Kim
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033
| | - Derek Sieburth
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033;
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
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12
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Synapsin Is Required for Dense Core Vesicle Capture and cAMP-Dependent Neuropeptide Release. J Neurosci 2021; 41:4187-4201. [PMID: 33820857 DOI: 10.1523/jneurosci.2631-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/11/2021] [Accepted: 03/09/2021] [Indexed: 11/21/2022] Open
Abstract
Release of neuropeptides from dense core vesicles (DCVs) is essential for neuromodulation. Compared with the release of small neurotransmitters, much less is known about the mechanisms and proteins contributing to neuropeptide release. By optogenetics, behavioral analysis, electrophysiology, electron microscopy, and live imaging, we show that synapsin SNN-1 is required for cAMP-dependent neuropeptide release in Caenorhabditis elegans hermaphrodite cholinergic motor neurons. In synapsin mutants, behaviors induced by the photoactivated adenylyl cyclase bPAC, which we previously showed to depend on ACh and neuropeptides (Steuer Costa et al., 2017), are altered as in animals with reduced cAMP. Synapsin mutants have slight alterations in synaptic vesicle (SV) distribution; however, a defect in SV mobilization was apparent after channelrhodopsin-based photostimulation. DCVs were largely affected in snn-1 mutants: DCVs were ∼30% reduced in synaptic terminals, and their contents not released following bPAC stimulation. Imaging axonal DCV trafficking, also in genome-engineered mutants in the serine-9 protein kinase A phosphorylation site, showed that synapsin captures DCVs at synapses, making them available for release. SNN-1 colocalized with immobile, captured DCVs. In synapsin deletion mutants, DCVs were more mobile and less likely to be caught at release sites, and in nonphosphorylatable SNN-1B(S9A) mutants, DCVs traffic less and accumulate, likely by enhanced SNN-1 dependent tethering. Our work establishes synapsin as a key mediator of neuropeptide release.SIGNIFICANCE STATEMENT Little is known about mechanisms that regulate how neuropeptide-containing dense core vesicles (DCVs) traffic along the axon, how neuropeptide release is orchestrated, and where it occurs. We found that one of the longest known synaptic proteins, required for the regulation of synaptic vesicles and their storage in nerve terminals, synapsin, is also essential for neuropeptide release. By electrophysiology, imaging, and electron microscopy in Caenorhabditis elegans, we show that synapsin regulates this process by tethering the DCVs to the cytoskeleton in axonal regions where neuropeptides are to be released. Without synapsin, DCVs cannot be captured at the release sites and, consequently, cannot fuse with the membrane, and neuropeptides are not released. We suggest that synapsin fulfills this role also in vertebrates, including humans.
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13
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Jia F, Chi C, Han M. Regulation of Nucleotide Metabolism and Germline Proliferation in Response to Nucleotide Imbalance and Genotoxic Stresses by EndoU Nuclease. Cell Rep 2021; 30:1848-1861.e5. [PMID: 32049015 PMCID: PMC7050212 DOI: 10.1016/j.celrep.2020.01.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/06/2019] [Accepted: 01/15/2020] [Indexed: 12/23/2022] Open
Abstract
Nucleotide deprivation and imbalance present detrimental conditions for animals and are thus expected to trigger cellular responses that direct protective changes in metabolic, developmental, and behavioral programs, albeit such mechanisms are vastly underexplored. Following our previous finding that Caenorhabditis elegans shut down germ cell proliferation in response to pyrimidine deprivation, we find in this study that endonuclease ENDU-2 regulates nucleotide metabolism and germ cell proliferation in response to nucleotide imbalance and other genotoxic stress, and that it affects mitotic chromosomal segregation in the intestine and lifespan. ENDU-2 expression is induced by nucleotide imbalance and genotoxic stress, and ENDU-2 exerts its function in the intestine, mostly by inhibiting the phosphorylation of CTPS-1 through repressing the PKA pathway and histone deacetylase HDA-1. Human EndoU also affects the response to genotoxic drugs. Our work reveals an unknown role of ENDU-2 in regulating nucleotide metabolism and animals' response to genotoxic stress, which may link EndoU function to cancer treatment.
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Affiliation(s)
- Fan Jia
- Department of Molecular, Cellular, and Developmental Biology (MCDB), University of Colorado at Boulder, Boulder, CO 80309-0347, USA.
| | - Congwu Chi
- Department of Molecular, Cellular, and Developmental Biology (MCDB), University of Colorado at Boulder, Boulder, CO 80309-0347, USA
| | - Min Han
- Department of Molecular, Cellular, and Developmental Biology (MCDB), University of Colorado at Boulder, Boulder, CO 80309-0347, USA
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14
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Thornquist SC, Pitsch MJ, Auth CS, Crickmore MA. Biochemical evidence accumulates across neurons to drive a network-level eruption. Mol Cell 2021; 81:675-690.e8. [PMID: 33453167 PMCID: PMC7924971 DOI: 10.1016/j.molcel.2020.12.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/05/2020] [Accepted: 12/15/2020] [Indexed: 11/19/2022]
Abstract
Neural network computations are usually assumed to emerge from patterns of fast electrical activity. Challenging this view, we show that a male fly's decision to persist in mating hinges on a biochemical computation that enables processing over minutes to hours. Each neuron in a recurrent network contains slightly different internal molecular estimates of mating progress. Protein kinase A (PKA) activity contrasts this internal measurement with input from the other neurons to represent accumulated evidence that the goal of the network has been achieved. When consensus is reached, PKA pushes the network toward a large-scale and synchronized burst of calcium influx that we call an eruption. Eruptions transform continuous deliberation within the network into an all-or-nothing output, after which the male will no longer sacrifice his life to continue mating. Here, biochemical activity, invisible to most large-scale recording techniques, is the key computational currency directing behavior and motivational state.
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Affiliation(s)
- Stephen C Thornquist
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Maximilian J Pitsch
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Charlotte S Auth
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Michael A Crickmore
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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15
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Shumilov AV, Gotovtsev PM. Modeling the activity of the dopamine signaling pathway by combination of analog electrical circuit and mathematical approaches. Heliyon 2021; 7:e05879. [PMID: 33553717 PMCID: PMC7855338 DOI: 10.1016/j.heliyon.2020.e05879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 12/22/2019] [Accepted: 12/24/2020] [Indexed: 11/24/2022] Open
Abstract
This paper demonstrates the application of the system biology principles on the example of the dopamine signaling pathway in neurons. Presented model is based on two approaches - cytomorphic electronic circuits and mathematical modeling. Transcription and phosphorylation of DARPP-32 was modeled by analog circuit, based on well-known approaches presented in [1]. It was shown that application of circuit helps to receive signal oscillations that close to described ones in real biological systems. This combination on the one hand gives possibility to simplify calculations, on another to show this signaling pathway dynamics. The expected effect of changes in the functioning of calcium channels is considered, and the mathematical model of the interaction of system components is proposed. The average frequency of calcium current oscillations due to the presence of dopamine was 30 Hz in presented model, that is consistent with the literature, where the frequency of such oscillations is up to several tens of Hz. All presented results shows good correlation with known data, which already published today.
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Affiliation(s)
- A V Shumilov
- National Research Centre "Kurchatov Institute", Biotechnology and Bioenergy Department, Russia.,Skolkovo Institute of Science and Technology, Informational Science and Technology, Russia
| | - P M Gotovtsev
- National Research Centre "Kurchatov Institute", Biotechnology and Bioenergy Department, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
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16
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Honer M, Buscemi K, Barrett N, Riazati N, Orlando G, Nelson MD. Orcokinin neuropeptides regulate sleep in Caenorhabditis elegans. J Neurogenet 2020; 34:440-452. [PMID: 33044108 DOI: 10.1080/01677063.2020.1830084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Orcokinin neuropeptides are conserved among ecdysozoans, but their functions are incompletely understood. Here, we report a role for orcokinin neuropeptides in the regulation of sleep in the nematode Caenorhabditis elegans. The C. elegans orcokinin peptides, which are encoded by the nlp-14 and nlp-15 genes, are necessary and sufficient for quiescent behaviors during developmentally timed sleep (DTS) as well as during stress-induced sleep (SIS). The five orcokinin neuropeptides encoded by nlp-14 have distinct but overlapping functions in the regulation of movement and defecation quiescence during SIS. We suggest that orcokinins may regulate behavioral components of sleep-like states in nematodes and other ecdysozoans.
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Affiliation(s)
- Madison Honer
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
| | - Kristen Buscemi
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
| | - Natalie Barrett
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
| | - Niknaz Riazati
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
| | - Gerald Orlando
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, PA, USA
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17
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Castaneda PG, Cecchetelli AD, Pettit HN, Cram EJ. Gα/GSA-1 works upstream of PKA/KIN-1 to regulate calcium signaling and contractility in the Caenorhabditis elegans spermatheca. PLoS Genet 2020; 16:e1008644. [PMID: 32776941 PMCID: PMC7444582 DOI: 10.1371/journal.pgen.1008644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 08/20/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
Correct regulation of cell contractility is critical for the function of many biological systems. The reproductive system of the hermaphroditic nematode C. elegans contains a contractile tube of myoepithelial cells known as the spermatheca, which stores sperm and is the site of oocyte fertilization. Regulated contraction of the spermatheca pushes the embryo into the uterus. Cell contractility in the spermatheca is dependent on actin and myosin and is regulated, in part, by Ca2+ signaling through the phospholipase PLC-1, which mediates Ca2+ release from the endoplasmic reticulum. Here, we describe a novel role for GSA-1/Gαs, and protein kinase A, composed of the catalytic subunit KIN-1/PKA-C and the regulatory subunit KIN-2/PKA-R, in the regulation of Ca2+ release and contractility in the C. elegans spermatheca. Without GSA-1/Gαs or KIN-1/PKA-C, Ca2+ is not released, and oocytes become trapped in the spermatheca. Conversely, when PKA is activated through either a gain of function allele in GSA-1 (GSA-1(GF)) or by depletion of KIN-2/PKA-R, the transit times and total numbers, although not frequencies, of Ca2+ pulses are increased, and Ca2+ propagates across the spermatheca even in the absence of oocyte entry. In the spermathecal-uterine valve, loss of GSA-1/Gαs or KIN-1/PKA-C results in sustained, high levels of Ca2+ and a loss of coordination between the spermathecal bag and sp-ut valve. Additionally, we show that depleting phosphodiesterase PDE-6 levels alters contractility and Ca2+ dynamics in the spermatheca, and that the GPB-1 and GPB-2 Gβ subunits play a central role in regulating spermathecal contractility and Ca2+ signaling. This work identifies a signaling network in which Ca2+ and cAMP pathways work together to coordinate spermathecal contractions for successful ovulations.
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Affiliation(s)
- Perla G. Castaneda
- Department of Biology, Northeastern University, Boston, MA, United States
| | | | - Hannah N. Pettit
- Department of Biology, Northeastern University, Boston, MA, United States
| | - Erin J. Cram
- Department of Biology, Northeastern University, Boston, MA, United States
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18
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Das S, Ooi FK, Cruz Corchado J, Fuller LC, Weiner JA, Prahlad V. Serotonin signaling by maternal neurons upon stress ensures progeny survival. eLife 2020; 9:e55246. [PMID: 32324136 PMCID: PMC7237211 DOI: 10.7554/elife.55246] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/22/2020] [Indexed: 01/03/2023] Open
Abstract
Germ cells are vulnerable to stress. Therefore, how organisms protect their future progeny from damage in a fluctuating environment is a fundamental question in biology. We show that in Caenorhabditis elegans, serotonin released by maternal neurons during stress ensures the viability and stress resilience of future offspring. Serotonin acts through a signal transduction pathway conserved between C. elegans and mammalian cells to enable the transcription factor HSF1 to alter chromatin in soon-to-be fertilized germ cells by recruiting the histone chaperone FACT, displacing histones, and initiating protective gene expression. Without serotonin release by maternal neurons, FACT is not recruited by HSF1 in germ cells, transcription occurs but is delayed, and progeny of stressed C. elegans mothers fail to complete development. These studies uncover a novel mechanism by which stress sensing by neurons is coupled to transcription response times of germ cells to protect future offspring.
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Affiliation(s)
- Srijit Das
- Department of Biology, Aging Mind and Brain InitiativeIowa CityUnited States
| | - Felicia K Ooi
- Department of Biology, Aging Mind and Brain InitiativeIowa CityUnited States
| | | | | | - Joshua A Weiner
- Department of BiologyIowa CityUnited States
- Iowa Neuroscience InstituteIowa CityUnited States
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain InitiativeIowa CityUnited States
- Department of BiologyIowa CityUnited States
- Iowa Neuroscience InstituteIowa CityUnited States
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19
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AMP-activated protein kinase slows D2 dopamine autoreceptor desensitization in substantia nigra neurons. Neuropharmacology 2019; 158:107705. [PMID: 31301335 DOI: 10.1016/j.neuropharm.2019.107705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/14/2022]
Abstract
Dopamine neurons in the substantia nigra zona compacta (SNC) are well known to express D2 receptors. When dopamine is released from somatodendritic sites, activation of D2 autoreceptors suppresses dopamine neuronal activity through activation of G protein-coupled K+ channels. AMP-activated protein kinase (AMPK) is a master enzyme that acts in somatic tissues to suppress energy expenditure and encourage energy production. We hypothesize that AMPK may also conserve energy in central neurons by reducing desensitization of D2 autoreceptors. We used whole-cell patch-clamp recordings to study the effects of AMPK activators and inhibitors on D2 autoreceptor-mediated current in SNC neurons in midbrain slices from rat pups (11-23 days post-natal). Slices were superfused with 100 μM dopamine or 30 μM quinpirole for 25 min, which evoked outward currents that decayed slowly over time. Although the AMPK activators A769662 and ZLN024 significantly slowed rundown of dopamine-evoked current, slowing of quinpirole-evoked current required the presence of a D1-like agonist (SKF38393). Moreover, the D1-like agonist also slowed the rundown of quinpirole-induced current even in the absence of an AMPK activator. Pharmacological antagonist experiments showed that the D1-like agonist effect required activation of either protein kinase A (PKA) or exchange protein directly activated by cAMP 2 (Epac2) pathways. In contrast, the effect of AMPK on rundown of current evoked by quinpirole plus SKF38393 required PKA but not Epac2. We conclude that AMPK slows D2 autoreceptor desensitization by augmenting the effect of D1-like receptors.
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20
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Split cGAL, an intersectional strategy using a split intein for refined spatiotemporal transgene control in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2018; 115:3900-3905. [PMID: 29581308 DOI: 10.1073/pnas.1720063115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bipartite expression systems, such as the GAL4-UAS system, allow fine manipulation of gene expression and are powerful tools for interrogating gene function. Recently, we established cGAL, a GAL4-based bipartite expression system for transgene control in Caenorhabditis elegans, where a single promoter dictates the expression pattern of a cGAL driver, which then binds target upstream activation sequences to drive expression of a downstream effector gene. Here, we report a split strategy for cGAL using the split intein gp41-1 for intersectional control of transgene expression. Split inteins are protein domains that associate, self-excise, and covalently ligate their flanking peptides together. We split the DNA binding domain and transcriptional activation domain of cGAL and fused them to the N terminal of gp41-1-N-intein and the C terminal of gp41-1-C-intein, respectively. In cells where both halves of cGAL are expressed, a functional cGAL driver is reconstituted via intein-mediated protein splicing. This reconstitution allows expression of the driver to be dictated by two promoters for refined spatial control or spatiotemporal control of transgene expression. We apply the split cGAL system to genetically access the single pair of MC neurons (previously inaccessible with a single promoter), and reveal an important role of protein kinase A in rhythmic pharyngeal pumping in C. elegans Thus, the split cGAL system gives researchers a greater degree of spatiotemporal control over transgene expression, and will be a valuable genetic tool in C. elegans for dissecting gene function with finer cell-specific resolution.
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21
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Electrophysiology of the rhythmic defecation program in nematode Heterorhabditis megidis. Sci Rep 2017; 7:17834. [PMID: 29259280 PMCID: PMC5736584 DOI: 10.1038/s41598-017-18118-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 12/06/2017] [Indexed: 11/08/2022] Open
Abstract
The nervous system controls most rhythmic behaviors, with a remarkable exception. In Caenorhabditis elegans periodic defecation rhythm does not appear to involve the nervous system. Such oscillations are studied in detail with genetic and molecular biology tools. The small size of C. elegans cells impairs the use of standard electrophysiological methods. We studied a similar rhythmic pacemaker in the noticeably larger gut cells of Heterorhabditis megidis nematode. H. megidis defecation cycle is driven by a central pattern generator (CPG) associated with unusual all-or-none hyper-polarization “action potential”. The CPG cycle period depends on the membrane potential and CPG cycling also persisted in experiments where the membrane potential of gut cells was continuously clamped at steady voltage levels. The usual excitable tissue description does not include the endoderm or imply the generation of hyper-polarization spikes. The nematode gut cells activity calls for a reevaluation of the excitable cells definition.
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22
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Xiao Y, Liu F, Zhao PJ, Zou CG, Zhang KQ. PKA/KIN-1 mediates innate immune responses to bacterial pathogens in Caenorhabditis elegans. Innate Immun 2017; 23:656-666. [PMID: 28958206 DOI: 10.1177/1753425917732822] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The genetically tractable organism Caenorhabditis elegans is a powerful model animal for the study of host innate immunity. Although the intestine and the epidermis of C. elegans that is in contact with pathogens are likely to function as sites for the immune function, recent studies indicate that the nervous system could control innate immunity in C. elegans. In this report, we demonstrated that protein kinase A (PKA)/KIN-1 in the neurons contributes to resistance against Salmonella enterica infection in C. elegans. Microarray analysis revealed that PKA/KIN-1 regulates the expression of a set of antimicrobial effectors in the non-neuron tissues, which are required for innate immune responses to S. enterica. Furthermore, PKA/KIN-1 regulated the expression of lysosomal genes during S. enterica infection. Our results suggest that the lysosomal signaling molecules are involved in autophagy by controlling autophagic flux, rather than formation of autophagosomes. As autophagy is crucial for host defense against S. enterica infection in a metazoan, the lysosomal pathway also acts as a downstream effector of the PKA/KIN-1 signaling for innate immunity. Our data indicate that the PKA pathway contributes to innate immunity in C. elegans by signaling from the nervous system to periphery tissues to protect the host against pathogens.
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Affiliation(s)
- Yi Xiao
- State Key laboratory for Conservation and Utilization of Bio-Resources in Yunnan, 12635 Yunnan University , Kunming, Yunnan, China
| | - Fang Liu
- State Key laboratory for Conservation and Utilization of Bio-Resources in Yunnan, 12635 Yunnan University , Kunming, Yunnan, China
| | - Pei-Ji Zhao
- State Key laboratory for Conservation and Utilization of Bio-Resources in Yunnan, 12635 Yunnan University , Kunming, Yunnan, China
| | - Cheng-Gang Zou
- State Key laboratory for Conservation and Utilization of Bio-Resources in Yunnan, 12635 Yunnan University , Kunming, Yunnan, China
| | - Ke-Qin Zhang
- State Key laboratory for Conservation and Utilization of Bio-Resources in Yunnan, 12635 Yunnan University , Kunming, Yunnan, China
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23
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Locomotion Behavior Is Affected by the Gα S Pathway and the Two-Pore-Domain K + Channel TWK-7 Interacting in GABAergic Motor Neurons in Caenorhabditis elegans. Genetics 2017; 206:283-297. [PMID: 28341653 DOI: 10.1534/genetics.116.195669] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/19/2017] [Indexed: 01/03/2023] Open
Abstract
Adjusting the efficiency of movement in response to environmental cues is an essential integrative characteristic of adaptive locomotion behavior across species. However, the modulatory molecules and the pathways involved are largely unknown. Recently, we demonstrated that in Caenorhabditis elegans, a loss-of-function of the two-pore-domain potassium (K2P) channel TWK-7 causes a fast, coordinated, and persistent forward crawling behavior in which five central aspects of stimulated locomotion-velocity, direction, wave parameters, duration, and straightness-are affected. Here, we isolated the reduction-of-function allele cau1 of the C. elegans gene kin-2 in a forward genetic screen and showed that it phenocopies the locomotor activity and locomotion behavior of twk-7(null) animals. Kin-2 encodes the negative regulatory subunit of protein kinase A (KIN-1/PKA). Consistently, we found that other gain-of-function mutants of the GαS-KIN-1/PKA pathway resemble kin-2(cau1) and twk-7(null) in locomotion phenotype. Using the powerful genetics of the C. elegans system in combination with cell type-specific approaches and detailed locomotion analyses, we identified TWK-7 as a putative downstream target of the GαS-KIN-1/PKA pathway at the level of the γ-aminobutyric acid (GABA)ergic D-type motor neurons. Due to this epistatic interaction, we suggest that KIN-1/PKA and TWK-7 may share a common pathway that is probably involved in the modulation of both locomotor activity and locomotion behavior during forward crawling.
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Steuer Costa W, Yu SC, Liewald JF, Gottschalk A. Fast cAMP Modulation of Neurotransmission via Neuropeptide Signals and Vesicle Loading. Curr Biol 2017; 27:495-507. [PMID: 28162892 DOI: 10.1016/j.cub.2016.12.055] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 12/06/2016] [Accepted: 12/27/2016] [Indexed: 02/02/2023]
Abstract
Cyclic AMP (cAMP) signaling augments synaptic transmission, but because many targets of cAMP and protein kinase A (PKA) may be involved, mechanisms underlying this pathway remain unclear. To probe this mechanism, we used optogenetic stimulation of cAMP signaling by Beggiatoa-photoactivated adenylyl cyclase (bPAC) in Caenorhabditis elegans motor neurons. Behavioral, electron microscopy (EM), and electrophysiology analyses revealed cAMP effects on both the rate and on quantal size of transmitter release and led to the identification of a neuropeptidergic pathway affecting quantal size. cAMP enhanced synaptic vesicle (SV) fusion by increasing mobilization and docking/priming. cAMP further evoked dense core vesicle (DCV) release of neuropeptides, in contrast to channelrhodopsin (ChR2) stimulation. cAMP-evoked DCV release required UNC-31/Ca2+-dependent activator protein for secretion (CAPS). Thus, DCVs accumulated in unc-31 mutant synapses. bPAC-induced neuropeptide signaling acts presynaptically to enhance vAChT-dependent SV loading with acetylcholine, thus causing increased miniature postsynaptic current amplitudes (mPSCs) and significantly enlarged SVs.
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Affiliation(s)
- Wagner Steuer Costa
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Szi-Chieh Yu
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany.
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Fang-Yen C, Alkema MJ, Samuel ADT. Illuminating neural circuits and behaviour in Caenorhabditis elegans with optogenetics. Philos Trans R Soc Lond B Biol Sci 2016; 370:20140212. [PMID: 26240427 DOI: 10.1098/rstb.2014.0212] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The development of optogenetics, a family of methods for using light to control neural activity via light-sensitive proteins, has provided a powerful new set of tools for neurobiology. These techniques have been particularly fruitful for dissecting neural circuits and behaviour in the compact and transparent roundworm Caenorhabditis elegans. Researchers have used optogenetic reagents to manipulate numerous excitable cell types in the worm, from sensory neurons, to interneurons, to motor neurons and muscles. Here, we show how optogenetics applied to this transparent roundworm has contributed to our understanding of neural circuits.
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Affiliation(s)
- Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Aravinthan D T Samuel
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
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Nagy S, Huang YC, Alkema MJ, Biron D. Caenorhabditis elegans exhibit a coupling between the defecation motor program and directed locomotion. Sci Rep 2015; 5:17174. [PMID: 26597056 PMCID: PMC4657007 DOI: 10.1038/srep17174] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/26/2015] [Indexed: 12/27/2022] Open
Abstract
Distinct motor programs can be coupled to refine the repertoire of behavior dynamics. However, mechanisms underlying such coupling are poorly understood. The defecation motor program (DMP) of C. elegans is composed of a succession of body contraction and expulsion steps, performed repeatedly with a period of 50-60 sec. We show that recurring patterns of directed locomotion are executed in tandem with, co-reset, and co-terminate with the DMP cycle. Calcium waves in the intestine and proton signaling were shown to regulate the DMP. We found that genetic manipulations affecting these calcium dynamics regulated the corresponding patterns of directed locomotion. Moreover, we observed the initiation of a recurring locomotion pattern 10 seconds prior to the posterior body contraction, suggesting that the synchronized motor program may initiate prior to the DMP. This study links two multi-step motor programs executed by C. elegans in synchrony, utilizing non-neuronal tissue to drive directed locomotion.
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Affiliation(s)
- Stanislav Nagy
- The Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL
| | - Yung-Chi Huang
- Department of Neurobiology, University of Ma ssachusetts Medical School, Worcester, MA
| | - Mark J Alkema
- Department of Neurobiology, University of Ma ssachusetts Medical School, Worcester, MA
| | - David Biron
- The Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL
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