1
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Hofbauer B, Zandawala M, Reinhard N, Rieger D, Werner C, Evers JF, Wegener C. The neuropeptide pigment-dispersing factor signals independently of Bruchpilot-labelled active zones in daily remodelled terminals of Drosophila clock neurons. Eur J Neurosci 2024; 59:2665-2685. [PMID: 38414155 DOI: 10.1111/ejn.16294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/29/2024]
Abstract
The small ventrolateral neurons (sLNvs) are key components of the central clock in the Drosophila brain. They signal via the neuropeptide pigment-dispersing factor (PDF) to align the molecular clockwork of different central clock neurons and to modulate downstream circuits. The dorsal terminals of the sLNvs undergo daily morphological changes that affect presynaptic sites organised by the active zone protein Bruchpilot (BRP), a homolog of mammalian ELKS proteins. However, the role of these presynaptic sites for PDF release is ill-defined. Here, we combined expansion microscopy with labelling of active zones by endogenously tagged BRP to examine the spatial correlation between PDF-containing dense-core vesicles and BRP-labelled active zones. We found that the number of BRP-labelled puncta in the sLNv terminals was similar while their density differed between Zeitgeber time (ZT) 2 and 14. The relative distance between BRP- and PDF-labelled puncta was increased in the morning, around the reported time of PDF release. Spontaneous dense-core vesicle release profiles of sLNvs in a publicly available ssTEM dataset (FAFB) consistently lacked spatial correlation to BRP-organised active zones. RNAi-mediated downregulation of brp and other active zone proteins expressed by the sLNvs did not affect PDF-dependent locomotor rhythmicity. In contrast, down-regulation of genes encoding proteins of the canonical vesicle release machinery, the dense-core vesicle-related protein CADPS, as well as PDF impaired locomotor rhythmicity. Taken together, our study suggests that PDF release from the sLNvs is independent of BRP-organised active zones, while BRP may be redistributed to active zones in a time-dependent manner.
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Affiliation(s)
- Benedikt Hofbauer
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Meet Zandawala
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
- Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV, USA
| | - Nils Reinhard
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Dirk Rieger
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Christian Werner
- Biocenter, Theodor-Boveri-Institute, Department of Biotechnology and Biophysics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Jan Felix Evers
- Centre for organismal studies COS, Universität Heidelberg, Heidelberg, Germany
- Cairn GmbH, Heidelberg, Germany
| | - Christian Wegener
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
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2
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Huang M, Wang Y, Chow CH, Stepien KP, Indrawinata K, Xu J, Argiropoulos P, Xie X, Sugita K, Tien CW, Lee S, Monnier PP, Rizo J, Gao S, Sugita S. Double mutation of open syntaxin and UNC-18 P334A leads to excitatory-inhibitory imbalance and impairs multiple aspects of C. elegans behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553709. [PMID: 37645974 PMCID: PMC10462135 DOI: 10.1101/2023.08.18.553709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
SNARE and Sec/Munc18 proteins are essential in synaptic vesicle exocytosis. Open form t-SNARE syntaxin and UNC-18 P334A are well-studied exocytosis-enhancing mutants. Here we investigate the interrelationship between the two mutations by generating double mutants in various genetic backgrounds in C. elegans. While each single mutation rescued the motility of CAPS/unc-31 and synaptotagmin/snt-1 mutants significantly, double mutations unexpectedly worsened motility or lost their rescuing effects. Electrophysiological analyses revealed that simultaneous mutations of open syntaxin and gain-of-function P334A UNC-18 induces a strong imbalance of excitatory over inhibitory transmission. In liposome fusion assays performed with mammalian proteins, the enhancement of fusion caused by the two mutations individually was abolished when the two mutations were introduced simultaneously, consistent with what we observed in C. elegans. We conclude that open syntaxin and P334A UNC-18 do not have additive beneficial effects, and this extends to C. elegans' characteristics such as motility, growth, offspring bared, body size, and exocytosis, as well as liposome fusion in vitro. Our results also reveal unexpected differences between the regulation of exocytosis in excitatory versus inhibitory synapses.
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Affiliation(s)
- Mengjia Huang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Ya Wang
- 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
| | - Chun Hin Chow
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Karolina P. Stepien
- Departments of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Karen Indrawinata
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Junjie Xu
- Departments of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Peter Argiropoulos
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Xiaoyu Xie
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - Kyoko Sugita
- Donald K. Johnson Eye Institute, University Health Network, Ontario, M5T 0S8, Canada; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Chi-Wei Tien
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Soomin Lee
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Philippe P. Monnier
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Ontario, M5T 0S8, Canada; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Josep Rizo
- Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - 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
- Key Laboratory of Vascular Aging of the Ministry of Education, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Shuzo Sugita
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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3
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Frank MM, Sitko AA, Suthakar K, Torres Cadenas L, Hunt M, Yuk MC, Weisz CJC, Goodrich LV. Experience-dependent flexibility in a molecularly diverse central-to-peripheral auditory feedback system. eLife 2023; 12:e83855. [PMID: 36876911 PMCID: PMC10147377 DOI: 10.7554/elife.83855] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/03/2023] [Indexed: 03/07/2023] Open
Abstract
Brainstem olivocochlear neurons (OCNs) modulate the earliest stages of auditory processing through feedback projections to the cochlea and have been shown to influence hearing and protect the ear from sound-induced damage. Here, we used single-nucleus sequencing, anatomical reconstructions, and electrophysiology to characterize murine OCNs during postnatal development, in mature animals, and after sound exposure. We identified markers for known medial (MOC) and lateral (LOC) OCN subtypes, and show that they express distinct cohorts of physiologically relevant genes that change over development. In addition, we discovered a neuropeptide-enriched LOC subtype that produces Neuropeptide Y along with other neurotransmitters. Throughout the cochlea, both LOC subtypes extend arborizations over wide frequency domains. Moreover, LOC neuropeptide expression is strongly upregulated days after acoustic trauma, potentially providing a sustained protective signal to the cochlea. OCNs are therefore poised to have diffuse, dynamic effects on early auditory processing over timescales ranging from milliseconds to days.
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Affiliation(s)
- Michelle M Frank
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Austen A Sitko
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Kirupa Suthakar
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication DisordersBethesdaUnited States
| | - Lester Torres Cadenas
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication DisordersBethesdaUnited States
| | - Mackenzie Hunt
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Mary Caroline Yuk
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Catherine JC Weisz
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication DisordersBethesdaUnited States
| | - Lisa V Goodrich
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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4
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Yeo XY, Lim YT, Chae WR, Park C, Park H, Jung S. Alterations of presynaptic proteins in autism spectrum disorder. Front Mol Neurosci 2022; 15:1062878. [DOI: 10.3389/fnmol.2022.1062878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 10/31/2022] [Indexed: 11/19/2022] Open
Abstract
The expanded use of hypothesis-free gene analysis methods in autism research has significantly increased the number of genetic risk factors associated with the pathogenesis of autism. A further examination of the implicated genes directly revealed the involvement in processes pertinent to neuronal differentiation, development, and function, with a predominant contribution from the regulators of synaptic function. Despite the importance of presynaptic function in synaptic transmission, the regulation of neuronal network activity, and the final behavioral output, there is a relative lack of understanding of the presynaptic contribution to the pathology of autism. Here, we will review the close association among autism-related mutations, autism spectrum disorders (ASD) phenotypes, and the altered presynaptic protein functions through a systematic examination of the presynaptic risk genes relating to the critical stages of synaptogenesis and neurotransmission.
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5
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Staudt A, Ratai O, Bouzouina A, Fecher-Trost C, Shaaban A, Bzeih H, Horn A, Shaib AH, Klose M, Flockerzi V, Lauterbach MA, Rettig J, Becherer U. Localization of the Priming Factors CAPS1 and CAPS2 in Mouse Sensory Neurons Is Determined by Their N-Termini. Front Mol Neurosci 2022; 15:674243. [PMID: 35493323 PMCID: PMC9049930 DOI: 10.3389/fnmol.2022.674243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
Abstract
Both paralogs of the calcium-dependent activator protein for secretion (CAPS) are required for exocytosis of synaptic vesicles (SVs) and large dense core vesicles (LDCVs). Despite approximately 80% sequence identity, CAPS1 and CAPS2 have distinct functions in promoting exocytosis of SVs and LDCVs in dorsal root ganglion (DRG) neurons. However, the molecular mechanisms underlying these differences remain enigmatic. In this study, we applied high- and super-resolution imaging techniques to systematically assess the subcellular localization of CAPS paralogs in DRG neurons deficient in both CAPS1 and CAPS2. CAPS1 was found to be more enriched at the synapses. Using – in-depth sequence analysis, we identified a unique CAPS1 N-terminal sequence, which we introduced into CAPS2. This CAPS1/2 chimera reproduced the pre-synaptic localization of CAPS1 and partially rescued synaptic transmission in neurons devoid of CAPS1 and CAPS2. Using immunoprecipitation combined with mass spectrometry, we identified CAPS1-specific interaction partners that could be responsible for its pre-synaptic enrichment. Taken together, these data suggest an important role of the CAPS1-N terminus in the localization of the protein at pre-synapses.
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Affiliation(s)
- Angelina Staudt
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Olga Ratai
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Aicha Bouzouina
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Claudia Fecher-Trost
- Department of Experimental and Clinical Pharmacology and Toxicology, Preclinical Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Ahmed Shaaban
- Department of Neuroscience, University of Copenhagen, København, Denmark
| | - Hawraa Bzeih
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Alexander Horn
- Department of Organic Chemistry, Saarland University, Saarbrücken, Germany
| | - Ali H. Shaib
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
- Institute for Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Margarete Klose
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Veit Flockerzi
- Department of Experimental and Clinical Pharmacology and Toxicology, Preclinical Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Marcel A. Lauterbach
- Department of Molecular Imaging, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Jens Rettig
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Ute Becherer
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
- *Correspondence: Ute Becherer,
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6
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Sitbon J, Nestvogel D, Kappeler C, Nicolas A, Maciuba S, Henrion A, Troudet R, Courtois E, Grannec G, Latapie V, Barau C, Le Corvoisier P, Pietrancosta N, Henry C, Leboyer M, Etain B, Nosten-Bertrand M, Martin TFJ, Rhee J, Jamain S. CADPS functional mutations in patients with bipolar disorder increase the sensitivity to stress. Mol Psychiatry 2022; 27:1145-1157. [PMID: 35169262 DOI: 10.1038/s41380-021-01151-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/19/2021] [Accepted: 04/29/2021] [Indexed: 11/09/2022]
Abstract
Bipolar disorder is a severe and chronic psychiatric disease resulting from a combination of genetic and environmental risk factors. Here, we identified a significant higher mutation rate in a gene encoding the calcium-dependent activator protein for secretion (CADPS) in 132 individuals with bipolar disorder, when compared to 184 unaffected controls or to 21,070 non-psychiatric and non-Finnish European subjects from the Exome Aggregation Consortium. We found that most of these variants resulted either in a lower abundance or a partial impairment in one of the basic functions of CADPS in regulating neuronal exocytosis, synaptic plasticity and vesicular transporter-dependent uptake of catecholamines. Heterozygous mutant mice for Cadps+/- revealed that a decreased level of CADPS leads to manic-like behaviours, changes in BDNF level and a hypersensitivity to stress. This was consistent with more childhood trauma reported in families with mutation in CADPS, and more specifically in mutated individuals. Furthermore, hyperactivity observed in mutant animals was rescued by the mood-stabilizing drug lithium. Overall, our results suggest that dysfunction in calcium-dependent vesicular exocytosis may increase the sensitivity to environmental stressors enhancing the risk of developing bipolar disorder.
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Affiliation(s)
- Jérémy Sitbon
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Dennis Nestvogel
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Caroline Kappeler
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Aude Nicolas
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Stephanie Maciuba
- Department of Biochemistry, University of Wisconsin, Madison, WI, USA
| | - Annabelle Henrion
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Réjane Troudet
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Elisa Courtois
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Gaël Grannec
- INSERM U1270, Sorbonne Université, Institut du Fer à Moulin, Paris, France
| | - Violaine Latapie
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France
| | - Caroline Barau
- AP-HP, Hôpital H. Mondor - A. Chenevier, Plateforme de Ressources Biologiques, Créteil, France
| | | | - Nicolas Pietrancosta
- Sorbonne University, École Normale Supérieure, PSL University, CNRS, Laboratoire des biomolécules (LBM), Paris, France.,Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France
| | - Chantal Henry
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France.,AP-HP, Hôpitaux Universitaires H. Mondor, DMU IMPACT, Créteil, France
| | - Marion Leboyer
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France.,Fondation FondaMental, Créteil, France.,AP-HP, Hôpitaux Universitaires H. Mondor, DMU IMPACT, Créteil, France
| | - Bruno Etain
- Fondation FondaMental, Créteil, France.,Département de Psychiatrie et de Médecine Addictologique, AP-HP, GH Saint-Louis - Lariboisière - F. Widal, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France.,Inserm, UMR-S1144, Paris, France
| | | | - Thomas F J Martin
- Department of Biochemistry, University of Wisconsin, Madison, WI, USA
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Stéphane Jamain
- Univ Paris Est Créteil, INSERM, IMRB, Translational Neuropsychiatry, Créteil, France. .,Fondation FondaMental, Créteil, France.
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7
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Banerjee A, Imig C, Balakrishnan K, Kershberg L, Lipstein N, Uronen RL, Wang J, Cai X, Benseler F, Rhee JS, Cooper BH, Liu C, Wojcik SM, Brose N, Kaeser PS. Molecular and functional architecture of striatal dopamine release sites. Neuron 2022; 110:248-265.e9. [PMID: 34767769 PMCID: PMC8859508 DOI: 10.1016/j.neuron.2021.10.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 09/22/2021] [Accepted: 10/19/2021] [Indexed: 01/21/2023]
Abstract
Despite the importance of dopamine for striatal circuit function, mechanistic understanding of dopamine transmission remains incomplete. We recently showed that dopamine secretion relies on the presynaptic scaffolding protein RIM, indicating that it occurs at active zone-like sites similar to classical synaptic vesicle exocytosis. Here, we establish using a systematic gene knockout approach that Munc13 and Liprin-α, active zone proteins for vesicle priming and release site organization, are important for dopamine secretion. Furthermore, RIM zinc finger and C2B domains, which bind to Munc13 and Liprin-α, respectively, are needed to restore dopamine release after RIM ablation. In contrast, and different from typical synapses, the active zone scaffolds RIM-BP and ELKS, and RIM domains that bind to them, are expendable. Hence, dopamine release necessitates priming and release site scaffolding by RIM, Munc13, and Liprin-α, but other active zone proteins are dispensable. Our work establishes that efficient release site architecture mediates fast dopamine exocytosis.
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Affiliation(s)
- Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | | | - Lauren Kershberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Noa Lipstein
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Riikka-Liisa Uronen
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jiexin Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Xintong Cai
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jeong Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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8
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Piao C, Sigrist SJ. (M)Unc13s in Active Zone Diversity: A Drosophila Perspective. Front Synaptic Neurosci 2022; 13:798204. [PMID: 35046788 PMCID: PMC8762327 DOI: 10.3389/fnsyn.2021.798204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/29/2021] [Indexed: 12/03/2022] Open
Abstract
The so-called active zones at pre-synaptic terminals are the ultimate filtering devices, which couple between action potential frequency and shape, and the information transferred to the post-synaptic neurons, finally tuning behaviors. Within active zones, the release of the synaptic vesicle operates from specialized “release sites.” The (M)Unc13 class of proteins is meant to define release sites topologically and biochemically, and diversity between Unc13-type release factor isoforms is suspected to steer diversity at active zones. The two major Unc13-type isoforms, namely, Unc13A and Unc13B, have recently been described from the molecular to the behavioral level, exploiting Drosophila being uniquely suited to causally link between these levels. The exact nanoscale distribution of voltage-gated Ca2+ channels relative to release sites (“coupling”) at pre-synaptic active zones fundamentally steers the release of the synaptic vesicle. Unc13A and B were found to be either tightly or loosely coupled across Drosophila synapses. In this review, we reported recent findings on diverse aspects of Drosophila Unc13A and B, importantly, their nano-topological distribution at active zones and their roles in release site generation, active zone assembly, and pre-synaptic homeostatic plasticity. We compared their stoichiometric composition at different synapse types, reviewing the correlation between nanoscale distribution of these two isoforms and release physiology and, finally, discuss how isoform-specific release components might drive the functional heterogeneity of synapses and encode discrete behavior.
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Affiliation(s)
- Chengji Piao
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
| | - Stephan J. Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany
- *Correspondence: Stephan J. Sigrist
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9
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Imambocus BN, Zhou F, Formozov A, Wittich A, Tenedini FM, Hu C, Sauter K, Macarenhas Varela E, Herédia F, Casimiro AP, Macedo A, Schlegel P, Yang CH, Miguel-Aliaga I, Wiegert JS, Pankratz MJ, Gontijo AM, Cardona A, Soba P. A neuropeptidergic circuit gates selective escape behavior of Drosophila larvae. Curr Biol 2021; 32:149-163.e8. [PMID: 34798050 DOI: 10.1016/j.cub.2021.10.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 10/05/2021] [Accepted: 10/29/2021] [Indexed: 12/26/2022]
Abstract
Animals display selective escape behaviors when faced with environmental threats. Selection of the appropriate response by the underlying neuronal network is key to maximizing chances of survival, yet the underlying network mechanisms are so far not fully understood. Using synapse-level reconstruction of the Drosophila larval network paired with physiological and behavioral readouts, we uncovered a circuit that gates selective escape behavior for noxious light through acute and input-specific neuropeptide action. Sensory neurons required for avoidance of noxious light and escape in response to harsh touch, each converge on discrete domains of neuromodulatory hub neurons. We show that acute release of hub neuron-derived insulin-like peptide 7 (Ilp7) and cognate relaxin family receptor (Lgr4) signaling in downstream neurons are required for noxious light avoidance, but not harsh touch responses. Our work highlights a role for compartmentalized circuit organization and neuropeptide release from regulatory hubs, acting as central circuit elements gating escape responses.
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Affiliation(s)
- Bibi Nusreen Imambocus
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Fangmin Zhou
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Andrey Formozov
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Annika Wittich
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Chun Hu
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Kathrin Sauter
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Ednilson Macarenhas Varela
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Fabiana Herédia
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Andreia P Casimiro
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - André Macedo
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Philipp Schlegel
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Chung-Hui Yang
- Department of Neurobiology, Duke University Medical School, 427E Bryan Research, Durham, NC 27710, USA
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - J Simon Wiegert
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Michael J Pankratz
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Alisson M Gontijo
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal; The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Albert Cardona
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; Department of Physiology, Development, and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Peter Soba
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany.
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10
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Page NF, Gandal MJ, Estes ML, Cameron S, Buth J, Parhami S, Ramaswami G, Murray K, Amaral DG, Van de Water JA, Schumann CM, Carter CS, Bauman MD, McAllister AK, Geschwind DH. Alterations in Retrotransposition, Synaptic Connectivity, and Myelination Implicated by Transcriptomic Changes Following Maternal Immune Activation in Nonhuman Primates. Biol Psychiatry 2021; 89:896-910. [PMID: 33386132 PMCID: PMC8052273 DOI: 10.1016/j.biopsych.2020.10.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Maternal immune activation (MIA) is a proposed risk factor for multiple neuropsychiatric disorders, including schizophrenia. However, the molecular mechanisms through which MIA imparts risk remain poorly understood. A recently developed nonhuman primate model of exposure to the viral mimic poly:ICLC during pregnancy shows abnormal social and repetitive behaviors and elevated striatal dopamine, a molecular hallmark of human psychosis, providing an unprecedented opportunity for studying underlying molecular correlates. METHODS We performed RNA sequencing across psychiatrically relevant brain regions (prefrontal cortex, anterior cingulate, hippocampus) and primary visual cortex for comparison from 3.5- to 4-year-old male MIA-exposed and control offspring-an age comparable to mid adolescence in humans. RESULTS We identify 266 unique genes differentially expressed in at least one brain region, with the greatest number observed in hippocampus. Co-expression networks identified region-specific alterations in synaptic signaling and oligodendrocytes. Although we observed temporal and regional differences, transcriptomic changes were shared across first- and second-trimester exposures, including for the top differentially expressed genes-PIWIL2 and MGARP. In addition to PIWIL2, several other regulators of retrotransposition and endogenous transposable elements were dysregulated following MIA, potentially connecting MIA to retrotransposition. CONCLUSIONS Together, these results begin to elucidate the brain-level molecular processes through which MIA may impart risk for psychiatric disease.
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Affiliation(s)
- Nicholas F Page
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California; Department of Cell Biology and Neuroscience, Rutgers University-New Brunswick, Piscataway, New Jersey
| | - Michael J Gandal
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California
| | - Myka L Estes
- Center for Neuroscience, School of Medicine, University of California, Davis, Davis, California
| | - Scott Cameron
- Center for Neuroscience, School of Medicine, University of California, Davis, Davis, California
| | - Jessie Buth
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California; Program in Neurobehavioral Genetics, Center for Autism Research and Treatment, Los Angeles, California
| | - Sepideh Parhami
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California; Program in Neurobehavioral Genetics, Center for Autism Research and Treatment, Los Angeles, California
| | - Gokul Ramaswami
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California; Program in Neurobehavioral Genetics, Center for Autism Research and Treatment, Los Angeles, California
| | - Karl Murray
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - David G Amaral
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - Judy A Van de Water
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - Cynthia M Schumann
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - Cameron S Carter
- Center for Neuroscience, School of Medicine, University of California, Davis, Davis, California; Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - Melissa D Bauman
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - A Kimberley McAllister
- Center for Neuroscience, School of Medicine, University of California, Davis, Davis, California; Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California, Davis, Davis, California
| | - Daniel H Geschwind
- Department of Psychiatry, Center for Autism Research and Treatment, Los Angeles, California; Program in Neurobehavioral Genetics, Center for Autism Research and Treatment, Los Angeles, California; Department of Neurology, Center for Autism Research and Treatment, Los Angeles, California; Department of Human Genetics, Semel Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California.
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11
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Jékely G. The chemical brain hypothesis for the origin of nervous systems. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190761. [PMID: 33550946 PMCID: PMC7935135 DOI: 10.1098/rstb.2019.0761] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
In nervous systems, there are two main modes of transmission for the propagation of activity between cells. Synaptic transmission relies on close contact at chemical or electrical synapses while volume transmission is mediated by diffusible chemical signals and does not require direct contact. It is possible to wire complex neuronal networks by both chemical and synaptic transmission. Both types of networks are ubiquitous in nervous systems, leading to the question which of the two appeared first in evolution. This paper explores a scenario where chemically organized cellular networks appeared before synapses in evolution, a possibility supported by the presence of complex peptidergic signalling in all animals except sponges. Small peptides are ideally suited to link up cells into chemical networks. They have unlimited diversity, high diffusivity and high copy numbers derived from repetitive precursors. But chemical signalling is diffusion limited and becomes inefficient in larger bodies. To overcome this, peptidergic cells may have developed projections and formed synaptically connected networks tiling body surfaces and displaying synchronized activity with pulsatile peptide release. The advent of circulatory systems and neurohemal organs further reduced the constraint imposed on chemical signalling by diffusion. This could have contributed to the explosive radiation of peptidergic signalling systems in stem bilaterians. Neurosecretory centres in extant nervous systems are still predominantly chemically wired and coexist with the synaptic brain. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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12
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Abstract
Neuropeptides are important for regulating numerous neural functions and behaviors. Release of neuropeptides requires long-lasting, high levels of cytosolic Ca2+ However, the molecular regulation of neuropeptide release remains to be clarified. Recently, Stac3 was identified as a key regulator of L-type Ca2+ channels (CaChs) and excitation-contraction coupling in vertebrate skeletal muscles. There is a small family of stac genes in vertebrates with other members expressed by subsets of neurons in the central nervous system. The function of neural Stac proteins, however, is poorly understood. Drosophila melanogaster contain a single stac gene, Dstac, which is expressed by muscles and a subset of neurons, including neuropeptide-expressing motor neurons. Here, genetic manipulations, coupled with immunolabeling, Ca2+ imaging, electrophysiology, and behavioral analysis, revealed that Dstac regulates L-type CaChs (Dmca1D) in Drosophila motor neurons and this, in turn, controls the release of neuropeptides.
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13
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Kliuchnikova AA, Goncharov AO, Levitsky LI, Pyatnitskiy MA, Novikova SE, Kuznetsova KG, Ivanov MV, Ilina IY, Farafonova TE, Zgoda VG, Gorshkov MV, Moshkovskii SA. Proteome-Wide Analysis of ADAR-Mediated Messenger RNA Editing during Fruit Fly Ontogeny. J Proteome Res 2020; 19:4046-4060. [PMID: 32866021 DOI: 10.1021/acs.jproteome.0c00347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Adenosine-to-inosine RNA editing is an enzymatic post-transcriptional modification which modulates immunity and neural transmission in multicellular organisms. In particular, it involves editing of mRNA codons with the resulting amino acid substitutions. We identified such sites for developmental proteomes of Drosophila melanogaster at the protein level using available data for 15 stages of fruit fly development from egg to imago and 14 time points of embryogenesis. In total, 40 sites were obtained, each belonging to a unique protein, including four sites related to embryogenesis. The interactome analysis has revealed that the majority of the editing-recoded proteins were associated with synaptic vesicle trafficking and actomyosin organization. Quantitation data analysis suggested the existence of a phase-specific RNA editing regulation with yet unknown mechanisms. These findings supported the transcriptome analysis results, which showed that a burst in the RNA editing occurs during insect metamorphosis from pupa to imago. Finally, targeted proteomic analysis was performed to quantify editing-recoded and genomically encoded versions of five proteins in brains of larvae, pupae, and imago insects, which showed a clear tendency toward an increase in the editing rate for each of them. These results will allow a better understanding of the protein role in physiological effects of RNA editing.
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Affiliation(s)
- Anna A Kliuchnikova
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia.,Pirogov Russian National Research Medical University, 1, Ostrovityanova, Moscow 117997, Russia
| | - Anton O Goncharov
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia.,Institute of Biomedical Chemistry, 10, Pogodinskaya, Moscow 119121, Russia
| | - Lev I Levitsky
- V.L. Talrose Institute for Energy Problems of Chemical Physics, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 38, bld. 1, Leninsky Prospect, Moscow 119334, Russia
| | - Mikhail A Pyatnitskiy
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia.,Institute of Biomedical Chemistry, 10, Pogodinskaya, Moscow 119121, Russia
| | | | - Ksenia G Kuznetsova
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia
| | - Mark V Ivanov
- V.L. Talrose Institute for Energy Problems of Chemical Physics, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 38, bld. 1, Leninsky Prospect, Moscow 119334, Russia
| | - Irina Y Ilina
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia
| | | | - Victor G Zgoda
- Institute of Biomedical Chemistry, 10, Pogodinskaya, Moscow 119121, Russia.,Skolkovo Institute of Science and Technology, 30, bld. 1, Bolshoy Boulevard, Moscow 121205, Russia
| | - Mikhail V Gorshkov
- V.L. Talrose Institute for Energy Problems of Chemical Physics, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 38, bld. 1, Leninsky Prospect, Moscow 119334, Russia
| | - Sergei A Moshkovskii
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow 119435, Russia.,Pirogov Russian National Research Medical University, 1, Ostrovityanova, Moscow 117997, Russia
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14
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CAPS1 Suppresses Tumorigenesis in Cholangiocarcinoma. Dig Dis Sci 2020; 65:1053-1063. [PMID: 31562609 DOI: 10.1007/s10620-019-05843-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/02/2019] [Indexed: 12/09/2022]
Abstract
BACKGROUND CAPS1 (calcium-dependent activator protein for secretion) is a multi-domain protein involved in regulating exocytosis of synaptic vesicles and dense-core vesicles. However, the expression and function of CAPS1 in cholangiocarcinoma (CCA) remains unclear. In the present study, we explored the role of CAPS1 in CCA carcinogenesis. METHODS CAPS1 expression was explored using western blotting and immunohistochemistry in four CCA cell lines and clinical samples from 90 cases of CCA. The clinical significance of CAPS1 was analyzed. The biological function of CAPS1 in CCA cells was detected in vitro and in vivo. The underlying mechanism of CAPS1 function was explored by detecting the expression of critical molecules in its associated signaling pathways. The mechanism of CAPS1 downregulation in tumor tissues was explored using in silico prediction and luciferase reporter assays. RESULTS CAPS1 expression was reduced in CCA cell lines and human tumor tissues. Loss of CAPS1 in tumor tissues was closely associated with poor prognosis of patients with CCA. Moreover, CAPS1 expression correlated significantly with tumor-node-metastasis stage, lymph node metastasis, and vascular invasion. Lentivirus-mediated CAPS1 overexpression substantially prevented clone formation, cell proliferation, and cell cycle progression. CAPS1 overexpression also suppressed carcinogenesis in nude mice. Mechanistically, CAPS1 overexpression greatly accelerated the ERK and p38 MAPK signal pathways. In addition, microRNA miR-30e-5p negatively regulated CAPS1 expression. CONCLUSION These data showed that CAPS1 functions as a tumor suppressor in CCA. Reduced CAPS1 expression could indicate poor prognosis of patients with CCA.
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15
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Tao L, Porto D, Li Z, Fechner S, Lee SA, Goodman MB, Xu XZS, Lu H, Shen K. Parallel Processing of Two Mechanosensory Modalities by a Single Neuron in C. elegans. Dev Cell 2019; 51:617-631.e3. [PMID: 31735664 DOI: 10.1016/j.devcel.2019.10.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 05/24/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Neurons convert synaptic or sensory inputs into cellular outputs. It is not well understood how a single neuron senses, processes multiple stimuli, and generates distinct neuronal outcomes. Here, we describe the mechanism by which the C. elegans PVD neurons sense two mechanical stimuli: external touch and proprioceptive body movement. These two stimuli are detected by distinct mechanosensitive DEG/ENaC/ASIC channels, which trigger distinct cellular outputs linked to mechanonociception and proprioception. Mechanonociception depends on DEGT-1 and activates PVD's downstream command interneurons through its axon, while proprioception depends on DEL-1, UNC-8, and MEC-10 to induce local dendritic Ca2+ increase and dendritic release of a neuropeptide NLP-12. NLP-12 directly modulates neuromuscular junction activity through the cholecystokinin receptor homolog on motor axons, setting muscle tone and movement vigor. Thus, the same neuron simultaneously uses both its axon and dendrites as output apparatus to drive distinct sensorimotor outcomes.
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Affiliation(s)
- Li Tao
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Daniel Porto
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Zhaoyu Li
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sylvia Fechner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Sol Ah Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - X Z Shawn Xu
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
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16
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Kuznetsova KG, Kliuchnikova AA, Ilina IU, Chernobrovkin AL, Novikova SE, Farafonova TE, Karpov DS, Ivanov MV, Goncharov AO, Ilgisonis EV, Voronko OE, Nasaev SS, Zgoda VG, Zubarev RA, Gorshkov MV, Moshkovskii SA. Proteogenomics of Adenosine-to-Inosine RNA Editing in the Fruit Fly. J Proteome Res 2018; 17:3889-3903. [DOI: 10.1021/acs.jproteome.8b00553] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | - Anna A. Kliuchnikova
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | | | | | | | - Dmitry S. Karpov
- Institute of Biomedical Chemistry, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mark V. Ivanov
- Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia
| | - Anton O. Goncharov
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | | | - Shamsudin S. Nasaev
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | - Roman A. Zubarev
- Karolinska Institutet, Stockholm, Sweden
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Mikhail V. Gorshkov
- Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia
| | - Sergei A. Moshkovskii
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
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17
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Calahorro F, Izquierdo PG. The presynaptic machinery at the synapse of C. elegans. INVERTEBRATE NEUROSCIENCE : IN 2018; 18:4. [PMID: 29532181 PMCID: PMC5851683 DOI: 10.1007/s10158-018-0207-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/22/2018] [Indexed: 11/17/2022]
Abstract
Synapses are specialized contact sites that mediate information flow between neurons and their targets. Important physical interactions across the synapse are mediated by synaptic adhesion molecules. These adhesions regulate formation of synapses during development and play a role during mature synaptic function. Importantly, genes regulating synaptogenesis and axon regeneration are conserved across the animal phyla. Genetic screens in the nematode Caenorhabditis elegans have identified a number of molecules required for synapse patterning and assembly. C. elegans is able to survive even with its neuronal function severely compromised. This is in comparison with Drosophila and mice where increased complexity makes them less tolerant to impaired function. Although this fact may reflect differences in the function of the homologous proteins in the synapses between these organisms, the most likely interpretation is that many of these components are equally important, but not absolutely essential, for synaptic transmission to support the relatively undemanding life style of laboratory maintained C. elegans. Here, we review research on the major group of synaptic proteins, involved in the presynaptic machinery in C. elegans, showing a strong conservation between higher organisms and highlight how C. elegans can be used as an informative tool for dissecting synaptic components, based on a simple nervous system organization.
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Affiliation(s)
- Fernando Calahorro
- Biological Sciences, University of Southampton, Life Sciences Building 85, Southampton, SO17 1BJ, UK.
| | - Patricia G Izquierdo
- Biological Sciences, University of Southampton, Life Sciences Building 85, Southampton, SO17 1BJ, UK
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18
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Deletion Involving the 7q31-32 Band at the CADPS2 Gene Locus in a Patient with Autism Spectrum Disorder and Recurrent Psychotic Syndrome Triggered by Stress. Case Rep Psychiatry 2017; 2017:4254152. [PMID: 29201482 PMCID: PMC5671701 DOI: 10.1155/2017/4254152] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/13/2017] [Indexed: 11/17/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by impairments in social functioning, language, communication, and behavior. Recent genome-wide association studies show some microdeletions on the 7q31-32 region, including the CADPS2 locus in autistic patients. This paper reports the case of a patient with ASD and recurrent psychotic syndrome, in which a deletion on the 7q31-32 band at the CADPS2 gene locus was evidenced, as well as a brief review of the literature on the CADPS2 gene and its association with ASD.
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19
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van Keimpema L, Kooistra R, Toonen RF, Verhage M. CAPS-1 requires its C2, PH, MHD1 and DCV domains for dense core vesicle exocytosis in mammalian CNS neurons. Sci Rep 2017; 7:10817. [PMID: 28883501 PMCID: PMC5589909 DOI: 10.1038/s41598-017-10936-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/16/2017] [Indexed: 01/11/2023] Open
Abstract
CAPS (calcium-dependent activator protein for secretion) are multi-domain proteins involved in regulated exocytosis of synaptic vesicles (SVs) and dense core vesicles (DCVs). Here, we assessed the contribution of different CAPS-1 domains to its subcellular localization and DCV exocytosis by expressing CAPS-1 mutations in four functional domains in CAPS-1/-2 null mutant (CAPS DKO) mouse hippocampal neurons, which are severely impaired in DCV exocytosis. CAPS DKO neurons showed normal development and no defects in DCV biogenesis and their subcellular distribution. Truncation of the CAPS-1 C-terminus (CAPS Δ654-1355) impaired CAPS-1 synaptic enrichment. Mutations in the C2 (K428E or G476E) or pleckstrin homology (PH; R558D/K560E/K561E) domain did not. However, all mutants rescued DCV exocytosis in CAPS DKO neurons to only 20% of wild type CAPS-1 exocytosis capacity. To assess the relative importance of CAPS for both secretory pathways, we compared effect sizes of CAPS-1/-2 deficiency on SV and DCV exocytosis. Using the same (intense) stimulation, DCV exocytosis was impaired relatively strong (96% inhibition) compared to SV exocytosis (39%). Together, these data show that the CAPS-1 C-terminus regulates synaptic enrichment of CAPS-1. All CAPS-1 functional domains are required, and the C2 and PH domain together are not sufficient, for DCV exocytosis in mammalian CNS neurons.
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Affiliation(s)
- Linda van Keimpema
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081 HV, Amsterdam, The Netherlands
- Sylics (Synaptologics BV), PO box 71033, 1008 BA, Amsterdam, The Netherlands
| | - Robbelien Kooistra
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081 HV, Amsterdam, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081 HV, Amsterdam, The Netherlands.
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081 HV, Amsterdam, The Netherlands.
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20
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Caenorhabditis elegans Male Copulation Circuitry Incorporates Sex-Shared Defecation Components To Promote Intromission and Sperm Transfer. G3-GENES GENOMES GENETICS 2017; 7:647-662. [PMID: 28031243 PMCID: PMC5295609 DOI: 10.1534/g3.116.036756] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sexual dimorphism can be achieved using a variety of mechanisms, including sex-specific circuits and sex-specific function of shared circuits, though how these work together to produce sexually dimorphic behaviors requires further investigation. Here, we explore how components of the sex-shared defecation circuitry are incorporated into the sex-specific male mating circuitry in Caenorhabditis elegans to produce successful copulation. Using behavioral studies, calcium imaging, and genetic manipulation, we show that aspects of the defecation system are coopted by the male copulatory circuitry to facilitate intromission and ejaculation. Similar to hermaphrodites, male defecation is initiated by an intestinal calcium wave, but circuit activity is coordinated differently during mating. In hermaphrodites, the tail neuron DVB promotes expulsion of gut contents through the release of the neurotransmitter GABA onto the anal depressor muscle. However, in the male, both neuron and muscle take on modified functions to promote successful copulation. Males require calcium-dependent activator protein for secretion (CAPS)/unc-31, a dense core vesicle exocytosis activator protein, in the DVB to regulate copulatory spicule insertion, while the anal depressor is remodeled to promote release of sperm into the hermaphrodite. This work shows how sex-shared circuitry is modified in multiple ways to contribute to sex-specific mating.
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21
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Analysis of gene expression in Ca2+-dependent activator protein for secretion 2 (Cadps2) knockout cerebellum using GeneChip and KEGG pathways. Neurosci Lett 2017; 639:88-93. [DOI: 10.1016/j.neulet.2016.12.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/09/2016] [Accepted: 12/28/2016] [Indexed: 11/20/2022]
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22
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Shinoda Y, Ishii C, Fukazawa Y, Sadakata T, Ishii Y, Sano Y, Iwasato T, Itohara S, Furuichi T. CAPS1 stabilizes the state of readily releasable synaptic vesicles to fusion competence at CA3-CA1 synapses in adult hippocampus. Sci Rep 2016; 6:31540. [PMID: 27545744 PMCID: PMC4992871 DOI: 10.1038/srep31540] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/21/2016] [Indexed: 01/06/2023] Open
Abstract
Calcium-dependent activator protein for secretion 1 (CAPS1) regulates exocytosis of dense-core vesicles in neuroendocrine cells and of synaptic vesicles in neurons. However, the synaptic function of CAPS1 in the mature brain is unclear because Caps1 knockout (KO) results in neonatal death. Here, using forebrain-specific Caps1 conditional KO (cKO) mice, we demonstrate, for the first time, a critical role of CAPS1 in adult synapses. The amplitude of synaptic transmission at CA3–CA1 synapses was strongly reduced, and paired-pulse facilitation was significantly increased, in acute hippocampal slices from cKO mice compared with control mice, suggesting a perturbation in presynaptic function. Morphological analysis revealed an accumulation of synaptic vesicles in the presynapse without any overall morphological change. Interestingly, however, the percentage of docked vesicles was markedly decreased in the Caps1 cKO. Taken together, our findings suggest that CAPS1 stabilizes the state of readily releasable synaptic vesicles, thereby enhancing neurotransmitter release at hippocampal synapses.
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Affiliation(s)
- Yo Shinoda
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan.,School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Chiaki Ishii
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Yugo Fukazawa
- Department of Brain Structure and Function, Faculty of Medical Sciences, University of Fukui, Yoshida-gun, Fukui 910-1193, Japan
| | - Tetsushi Sadakata
- Advanced Scientific Research Leaders Development Unit, Gunma University, Maebashi, Gunma 371-8511, Japan
| | - Yuki Ishii
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Yoshitake Sano
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Takuji Iwasato
- Division of Neurogenetics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
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23
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Musashe DT, Purice MD, Speese SD, Doherty J, Logan MA. Insulin-like Signaling Promotes Glial Phagocytic Clearance of Degenerating Axons through Regulation of Draper. Cell Rep 2016; 16:1838-50. [PMID: 27498858 DOI: 10.1016/j.celrep.2016.07.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 05/23/2016] [Accepted: 07/09/2016] [Indexed: 01/15/2023] Open
Abstract
Neuronal injury triggers robust responses from glial cells, including altered gene expression and enhanced phagocytic activity to ensure prompt removal of damaged neurons. The molecular underpinnings of glial responses to trauma remain unclear. Here, we find that the evolutionarily conserved insulin-like signaling (ILS) pathway promotes glial phagocytic clearance of degenerating axons in adult Drosophila. We find that the insulin-like receptor (InR) and downstream effector Akt1 are acutely activated in local ensheathing glia after axotomy and are required for proper clearance of axonal debris. InR/Akt1 activity, it is also essential for injury-induced activation of STAT92E and its transcriptional target draper, which encodes a conserved receptor essential for glial engulfment of degenerating axons. Increasing Draper levels in adult glia partially rescues delayed clearance of severed axons in glial InR-inhibited flies. We propose that ILS functions as a key post-injury communication relay to activate glial responses, including phagocytic activity.
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Affiliation(s)
- Derek T Musashe
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR 97239, USA
| | - Maria D Purice
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR 97239, USA
| | - Sean D Speese
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR 97239, USA
| | - Johnna Doherty
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 55 North Lake Avenue, Worcester, MA 01605, USA
| | - Mary A Logan
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR 97239, USA.
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24
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Davis SM, Thomas AL, Nomie KJ, Huang L, Dierick HA. Tailless and Atrophin control Drosophila aggression by regulating neuropeptide signalling in the pars intercerebralis. Nat Commun 2016; 5:3177. [PMID: 24495972 DOI: 10.1038/ncomms4177] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 12/23/2013] [Indexed: 01/21/2023] Open
Abstract
Aggressive behaviour is widespread throughout the animal kingdom. However, its mechanisms are poorly understood, and the degree of molecular conservation between distantly related species is unknown. Here we show that knockdown of tailless (tll) increases aggression in Drosophila, similar to the effect of its mouse orthologue Nr2e1. Tll localizes to the adult pars intercerebralis (PI), which shows similarity to the mammalian hypothalamus. Knockdown of tll in the PI is sufficient to increase aggression and is rescued by co-expressing human NR2E1. Knockdown of Atrophin, a Tll co-repressor, also increases aggression, and both proteins physically interact in the PI. tll knockdown-induced aggression is fully suppressed by blocking neuropeptide processing or release from the PI. In addition, genetically activating PI neurons increases aggression, mimicking the aggression-inducing effect of hypothalamic stimulation. Together, our results suggest that a transcriptional control module regulates neuropeptide signalling from the neurosecretory cells of the brain to control aggressive behaviour.
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Affiliation(s)
- Shaun M Davis
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA [2]
| | - Amanda L Thomas
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA [2]
| | - Krystle J Nomie
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA [2]
| | - Longwen Huang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Herman A Dierick
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA [2] Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas 77030, USA [3] Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA [4] Program in Developmental Biology, Houston, Texas 77030, USA
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25
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Interaction of Ca(2+)-dependent activator protein for secretion 1 (CAPS1) with septin family proteins in mouse brain. Neurosci Lett 2016; 617:232-5. [PMID: 26917099 DOI: 10.1016/j.neulet.2016.02.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/18/2016] [Accepted: 02/19/2016] [Indexed: 01/22/2023]
Abstract
The Ca(2+)-dependent activator protein for secretion 1 (CAPS1) protein plays a regulatory role in the dense-core vesicle exocytosis pathway. To clarify the functions of this protein in the brain, we searched for novel interaction partners of CAPS1 by mass spectrometry. We identified a specific interaction of CAPS1 with septin family proteins. We also demonstrated that the C-terminal region of the CAPS1 protein binds to part of the deduced GTP-binding domain of septin proteins. It is possible that a tertiary complex of septin, CAPS, and syntaxin contributes to dense-core vesicle trafficking and exocytosis in neurons.
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26
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Kabachinski G, Kielar-Grevstad DM, Zhang X, James DJ, Martin TFJ. Resident CAPS on dense-core vesicles docks and primes vesicles for fusion. Mol Biol Cell 2016; 27:654-68. [PMID: 26700319 PMCID: PMC4750925 DOI: 10.1091/mbc.e15-07-0509] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 12/12/2015] [Accepted: 12/18/2015] [Indexed: 11/11/2022] Open
Abstract
The Ca(2+)-dependent exocytosis of dense-core vesicles in neuroendocrine cells requires a priming step during which SNARE protein complexes assemble. CAPS (aka CADPS) is one of several factors required for vesicle priming; however, the localization and dynamics of CAPS at sites of exocytosis in live neuroendocrine cells has not been determined. We imaged CAPS before, during, and after single-vesicle fusion events in PC12 cells by TIRF micro-scopy. In addition to being a resident on cytoplasmic dense-core vesicles, CAPS was present in clusters of approximately nine molecules near the plasma membrane that corresponded to docked/tethered vesicles. CAPS accompanied vesicles to the plasma membrane and was present at all vesicle exocytic events. The knockdown of CAPS by shRNA eliminated the VAMP-2-dependent docking and evoked exocytosis of fusion-competent vesicles. A CAPS(ΔC135) protein that does not localize to vesicles failed to rescue vesicle docking and evoked exocytosis in CAPS-depleted cells, showing that CAPS residence on vesicles is essential. Our results indicate that dense-core vesicles carry CAPS to sites of exocytosis, where CAPS promotes vesicle docking and fusion competence, probably by initiating SNARE complex assembly.
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Affiliation(s)
- Greg Kabachinski
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706
| | | | - Xingmin Zhang
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706
| | - Declan J James
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706
| | - Thomas F J Martin
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706
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27
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Man KNM, Imig C, Walter AM, Pinheiro PS, Stevens DR, Rettig J, Sørensen JB, Cooper BH, Brose N, Wojcik SM. Identification of a Munc13-sensitive step in chromaffin cell large dense-core vesicle exocytosis. eLife 2015; 4. [PMID: 26575293 PMCID: PMC4798968 DOI: 10.7554/elife.10635] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/16/2015] [Indexed: 01/16/2023] Open
Abstract
It is currently unknown whether the molecular steps of large dense-core vesicle (LDCV) docking and priming are identical to the corresponding reactions in synaptic vesicle (SV) exocytosis. Munc13s are essential for SV docking and priming, and we systematically analyzed their role in LDCV exocytosis using chromaffin cells lacking individual isoforms. We show that particularly Munc13-2 plays a fundamental role in LDCV exocytosis, but in contrast to synapses lacking Munc13s, the corresponding chromaffin cells do not exhibit a vesicle docking defect. We further demonstrate that ubMunc13-2 and Munc13-1 confer Ca(2+)-dependent LDCV priming with similar affinities, but distinct kinetics. Using a mathematical model, we identify an early LDCV priming step that is strongly dependent upon Munc13s. Our data demonstrate that the molecular steps of SV and LDCV priming are very similar while SV and LDCV docking mechanisms are distinct.
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Affiliation(s)
- Kwun Nok M Man
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | | | - Paulo S Pinheiro
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences and Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
| | - David R Stevens
- Department of Physiology, Saarland University, Homburg, Germany
| | - Jens Rettig
- Department of Physiology, Saarland University, Homburg, Germany
| | - Jakob B Sørensen
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences and Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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28
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Harris KP, Littleton JT. Transmission, Development, and Plasticity of Synapses. Genetics 2015; 201:345-75. [PMID: 26447126 PMCID: PMC4596655 DOI: 10.1534/genetics.115.176529] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/28/2015] [Indexed: 01/03/2023] Open
Abstract
Chemical synapses are sites of contact and information transfer between a neuron and its partner cell. Each synapse is a specialized junction, where the presynaptic cell assembles machinery for the release of neurotransmitter, and the postsynaptic cell assembles components to receive and integrate this signal. Synapses also exhibit plasticity, during which synaptic function and/or structure are modified in response to activity. With a robust panel of genetic, imaging, and electrophysiology approaches, and strong evolutionary conservation of molecular components, Drosophila has emerged as an essential model system for investigating the mechanisms underlying synaptic assembly, function, and plasticity. We will discuss techniques for studying synapses in Drosophila, with a focus on the larval neuromuscular junction (NMJ), a well-established model glutamatergic synapse. Vesicle fusion, which underlies synaptic release of neurotransmitters, has been well characterized at this synapse. In addition, studies of synaptic assembly and organization of active zones and postsynaptic densities have revealed pathways that coordinate those events across the synaptic cleft. We will also review modes of synaptic growth and plasticity at the fly NMJ, and discuss how pre- and postsynaptic cells communicate to regulate plasticity in response to activity.
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Affiliation(s)
- Kathryn P Harris
- Department of Biology and Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - J Troy Littleton
- Department of Biology and Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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29
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Farina M, van de Bospoort R, He E, Persoon CM, van Weering JRT, Broeke JH, Verhage M, Toonen RF. CAPS-1 promotes fusion competence of stationary dense-core vesicles in presynaptic terminals of mammalian neurons. eLife 2015; 4. [PMID: 25719439 PMCID: PMC4341531 DOI: 10.7554/elife.05438] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/09/2015] [Indexed: 01/03/2023] Open
Abstract
Neuropeptides released from dense-core vesicles (DCVs) modulate neuronal activity, but the molecules driving DCV secretion in mammalian neurons are largely unknown. We studied the role of calcium-activator protein for secretion (CAPS) proteins in neuronal DCV secretion at single vesicle resolution. Endogenous CAPS-1 co-localized with synaptic markers but was not enriched at every synapse. Deletion of CAPS-1 and CAPS-2 did not affect DCV biogenesis, loading, transport or docking, but DCV secretion was reduced by 70% in CAPS-1/CAPS-2 double null mutant (DKO) neurons and remaining fusion events required prolonged stimulation. CAPS deletion specifically reduced secretion of stationary DCVs. CAPS-1-EYFP expression in DKO neurons restored DCV secretion, but CAPS-1-EYFP and DCVs rarely traveled together. Synaptic localization of CAPS-1-EYFP in DKO neurons was calcium dependent and DCV fusion probability correlated with synaptic CAPS-1-EYFP expression. These data indicate that CAPS-1 promotes fusion competence of immobile (tethered) DCVs in presynaptic terminals and that CAPS-1 localization to DCVs is probably not essential for this role. DOI:http://dx.doi.org/10.7554/eLife.05438.001 Our ability to think and act is due to the remarkable capacity of the brain to process complex information. This involves nerve cells (or neurons) communicating with each other in a rapid and precise manner by releasing synaptic vesicles containing neurotransmitters across the gaps—called synapses—between neurons. In addition to this fast neurotransmitter signalling, neurons can transmit signals by releasing chemical signals called neuropeptides. Neuropeptides are major regulators of human brain function, including mood, anxiety, and social interactions. Neuropeptides and other neuromodulators such as serotonin and dopamine are normally packaged into bubble-like compartments called dense-core vesicles. Compared to synaptic vesicles we know much less about how dense-core vesicles are trafficked and released. Dense-core vesicles are generally mobile and move around the inside of cells to release neuropeptides where and when they are needed. However, some vesicles are stationary and may even be loosely tethered to the cell membrane. Most of the sites where dense-core vesicles can fuse with the cell membrane are at synapses. Previous work has suggested that the protein CAPS-1 is important for moving dense-core vesicles to the correct sites on the cell membrane, and for releasing neuropeptides across the synapses of worms and flies. However, detailed insights into this process in mammalian neurons are lacking. By examining neurons from both normal mice and mice lacking the CAPS-1 protein, Farina et al. have now analyzed the role CAPS-1 plays in releasing neuropeptides. In cells lacking CAPS-1 fewer dense-core vesicles merged with the cell membrane than in cells containing the protein. However, a new technique that tracks the movement of individual vesicles revealed that only stationary dense-core vesicles had difficulties fusing; mobile vesicles continued to fuse with the cell membrane in the normal manner. Introducing CAPS-1 into cells lacking this protein corrected the fusion defect experienced by the stationary vesicles. Farina et al. also showed that CAPS-1 was present at most—but not all—synapses, and synapses that had more CAPS-1 released more neuropeptides. This work shows that CAPS proteins strongly influence the probability of dense-core vesicle release and that neurons can tune this probability at individual synapses by controlling the expression of CAPS. Future work will be aimed at understanding how neurons can achieve this and which protein domains in CAPS are required. DOI:http://dx.doi.org/10.7554/eLife.05438.002
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Affiliation(s)
- Margherita Farina
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Rhea van de Bospoort
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Enqi He
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Claudia M Persoon
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, Netherlands
| | - Jan R T van Weering
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, Netherlands
| | - Jurjen H Broeke
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
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30
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Vogl C, Cooper BH, Neef J, Wojcik SM, Reim K, Reisinger E, Brose N, Rhee JS, Moser T, Wichmann C. Unconventional molecular regulation of synaptic vesicle replenishment in cochlear inner hair cells. J Cell Sci 2015; 128:638-44. [PMID: 25609709 DOI: 10.1242/jcs.162099] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Ribbon synapses of cochlear inner hair cells (IHCs) employ efficient vesicle replenishment to indefatigably encode sound. In neurons, neuroendocrine and immune cells, vesicle replenishment depends on proteins of the mammalian uncoordinated 13 (Munc13, also known as Unc13) and Ca(2+)-dependent activator proteins for secretion (CAPS) families, which prime vesicles for exocytosis. Here, we tested whether Munc13 and CAPS proteins also regulate exocytosis in mouse IHCs by combining immunohistochemistry with auditory systems physiology and IHC patch-clamp recordings of exocytosis in mice lacking Munc13 and CAPS isoforms. Surprisingly, we did not detect Munc13 or CAPS proteins at IHC presynaptic active zones and found normal IHC exocytosis as well as auditory brainstem responses (ABRs) in Munc13 and CAPS deletion mutants. Instead, we show that otoferlin, a C2-domain protein that is crucial for vesicular fusion and replenishment in IHCs, clusters at the plasma membrane of the presynaptic active zone. Electron tomography of otoferlin-deficient IHC synapses revealed a reduction of short tethers holding vesicles at the active zone, which might be a structural correlate of impaired vesicle priming in otoferlin-deficient IHCs. We conclude that IHCs use an unconventional priming machinery that involves otoferlin.
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Affiliation(s)
- Christian Vogl
- Institute for Auditory Neuroscience and InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jakob Neef
- Institute for Auditory Neuroscience and InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Kerstin Reim
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Ellen Reisinger
- Molecular Biology of Cochlear Neurotransmission Group, InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University of Göttingen, 37073 Göttingen, Germany
| | - Jeong-Seop Rhee
- Neurophysiology Group, Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, 37099 Göttingen, Germany Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University of Göttingen, 37073 Göttingen, Germany
| | - Carolin Wichmann
- Institute for Auditory Neuroscience and InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, 37099 Göttingen, Germany Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany
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31
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Abstract
Genetic manipulations of neuronal activity are a cornerstone of studies aimed to identify the functional impact of defined neurons for animal behavior. With its small nervous system, rapid life cycle, and genetic amenability, the fruit fly Drosophila melanogaster provides an attractive model system to study neuronal circuit function. In the past two decades, a large repertoire of elegant genetic tools has been developed to manipulate and study neural circuits in the fruit fly. Current techniques allow genetic ablation, constitutive silencing, or hyperactivation of neuronal activity and also include conditional thermogenetic or optogenetic activation or inhibition. As for all genetic techniques, the choice of the proper transgenic tool is essential for behavioral studies. Potency and impact of effectors may vary in distinct neuron types or distinct types of behavior. We here systematically test genetic effectors for their potency to alter the behavior of Drosophila larvae, using two distinct behavioral paradigms: general locomotor activity and directed, visually guided navigation. Our results show largely similar but not equal effects with different effector lines in both assays. Interestingly, differences in the magnitude of induced behavioral alterations between different effector lines remain largely consistent between the two behavioral assays. The observed potencies of the effector lines in aminergic and cholinergic neurons assessed here may help researchers to choose the best-suited genetic tools to dissect neuronal networks underlying the behavior of larval fruit flies.
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32
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Imig C, Min SW, Krinner S, Arancillo M, Rosenmund C, Südhof TC, Rhee J, Brose N, Cooper BH. The morphological and molecular nature of synaptic vesicle priming at presynaptic active zones. Neuron 2014; 84:416-31. [PMID: 25374362 DOI: 10.1016/j.neuron.2014.10.009] [Citation(s) in RCA: 277] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2014] [Indexed: 12/22/2022]
Abstract
Synaptic vesicle docking, priming, and fusion at active zones are orchestrated by a complex molecular machinery. We employed hippocampal organotypic slice cultures from mice lacking key presynaptic proteins, cryofixation, and three-dimensional electron tomography to study the mechanism of synaptic vesicle docking in the same experimental setting, with high precision, and in a near-native state. We dissected previously indistinguishable, sequential steps in synaptic vesicle active zone recruitment (tethering) and membrane attachment (docking) and found that vesicle docking requires Munc13/CAPS family priming proteins and all three neuronal SNAREs, but not Synaptotagmin-1 or Complexins. Our data indicate that membrane-attached vesicles comprise the readily releasable pool of fusion-competent vesicles and that synaptic vesicle docking, priming, and trans-SNARE complex assembly are the respective morphological, functional, and molecular manifestations of the same process, which operates downstream of vesicle tethering by active zone components.
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Affiliation(s)
- Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Sang-Won Min
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stefanie Krinner
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Marife Arancillo
- Neuroscience Research Center and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Christian Rosenmund
- Neuroscience Research Center and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
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33
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Li Q, Wang Z, Lian J, Schiøtt M, Jin L, Zhang P, Zhang Y, Nygaard S, Peng Z, Zhou Y, Deng Y, Zhang W, Boomsma JJ, Zhang G. Caste-specific RNA editomes in the leaf-cutting ant Acromyrmex echinatior. Nat Commun 2014; 5:4943. [PMID: 25266559 PMCID: PMC4200514 DOI: 10.1038/ncomms5943] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 08/08/2014] [Indexed: 01/16/2023] Open
Abstract
Eusocial insects have evolved the capacity to generate adults with distinct morphological, reproductive and behavioural phenotypes from the same genome. Recent studies suggest that RNA editing might enhance the diversity of gene products at the post-transcriptional level, particularly to induce functional changes in the nervous system. Using head samples from the leaf-cutting ant Acromyrmex echinatior, we compare RNA editomes across eusocial castes, identifying ca. 11,000 RNA editing sites in gynes, large workers and small workers. Those editing sites map to 800 genes functionally enriched for neurotransmission, circadian rhythm, temperature response, RNA splicing and carboxylic acid biosynthesis. Most A. echinatior editing sites are species specific, but 8–23% are conserved across ant subfamilies and likely to have been important for the evolution of eusociality in ants. The level of editing varies for the same site between castes, suggesting that RNA editing might be a general mechanism that shapes caste behaviour in ants. Post-translational mRNA editing has the potential to enhance the diversity of gene products and alter the functional properties of proteins. Here, Li et al. provide evidence that RNA editing is involved in generating caste-specific contrasting phenotypes in the leaf-cutting ant Acromyrmex echinatior.
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Affiliation(s)
- Qiye Li
- 1] School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China [2] China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Zongji Wang
- 1] School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China [2] China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Jinmin Lian
- China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Lijun Jin
- China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Pei Zhang
- China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | | | - Sanne Nygaard
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | | | - Yang Zhou
- 1] School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China [2] China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Yuan Deng
- China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | | | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Guojie Zhang
- 1] China National GeneBank, BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China [2] Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
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Li C, Kim K. Family of FLP Peptides in Caenorhabditis elegans and Related Nematodes. Front Endocrinol (Lausanne) 2014; 5:150. [PMID: 25352828 PMCID: PMC4196577 DOI: 10.3389/fendo.2014.00150] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/09/2014] [Indexed: 11/16/2022] Open
Abstract
Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system have been identified. The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides (FaRPs). These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FaRPs described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and signaling pathways through which they function.
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Affiliation(s)
- Chris Li
- Department of Biology, City College of New York and The Graduate Center, City University of New York, New York, NY, USA
- *Correspondence: Chris Li, 160 Convent Avenue, MR526, New York, NY 10031, USA e-mail: ; Kyuhyung Kim, 333 Techno Jungang-Daero, Hyeonpung-Myeon, Dalseong-Gun, Daegu 711-873, South Korea e-mail:
| | - Kyuhyung Kim
- Department of Brain Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
- *Correspondence: Chris Li, 160 Convent Avenue, MR526, New York, NY 10031, USA e-mail: ; Kyuhyung Kim, 333 Techno Jungang-Daero, Hyeonpung-Myeon, Dalseong-Gun, Daegu 711-873, South Korea e-mail:
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CAPS1 deficiency perturbs dense-core vesicle trafficking and Golgi structure and reduces presynaptic release probability in the mouse brain. J Neurosci 2013; 33:17326-34. [PMID: 24174665 DOI: 10.1523/jneurosci.2777-13.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ca(2+)-dependent activator protein for secretion 1 (CAPS1) plays a regulatory role in the dense-core vesicle (DCV) exocytosis pathway, but its functions at the cellular and synaptic levels in the brain are essentially unknown because of neonatal death soon after birth in Caps1 knock-out mice. To clarify the functions of the protein in the brain, we generated two conditional knock-out (cKO) mouse lines: 1) one lacking Caps1 in the forebrain; and 2) the other lacking Caps1 in the cerebellum. Both cKO mouse lines were born normally and grew to adulthood, although they showed subcellular and synaptic abnormalities. Forebrain-specific Caps1 cKO mice showed reduced immunoreactivity for the DCV marker secretogranin II (SgII) and the trans-Golgi network (TGN) marker syntaxin 6, a reduced number of presynaptic DCVs, and dilated trans-Golgi cisternae in the CA3 region. Cerebellum-specific Caps1 cKO mice had decreased immunoreactivity for SgII and brain-derived neurotrophic factor (BDNF) along the climbing fibers. At climbing fiber-Purkinje cell synapses, the number of DCVs was markedly lower and the number of synaptic vesicles was also reduced. Correspondingly, the mean amplitude of EPSCs was decreased, whereas paired-pulse depression was significantly increased. Our results suggest that loss of CAPS1 disrupts the TGN-DCV pathway, which possibly impairs synaptic transmission by reducing the presynaptic release probability.
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Parsaud L, Li L, Jung CH, Park S, Saw NMN, Park S, Kim MY, Sugita S. Calcium-dependent activator protein for secretion 1 (CAPS1) binds to syntaxin-1 in a distinct mode from Munc13-1. J Biol Chem 2013; 288:23050-63. [PMID: 23801330 DOI: 10.1074/jbc.m113.494088] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Calcium-dependent activator protein for secretion 1 (CAPS1) is a multidomain protein containing a Munc13 homology domain 1 (MHD1). Although CAPS1 and Munc13-1 play crucial roles in the priming stage of secretion, their functions are non-redundant. Similar to Munc13-1, CAPS1 binds to syntaxin-1, a key t-SNARE protein in neurosecretion. However, whether CAPS1 interacts with syntaxin-1 in a similar mode to Munc13-1 remains unclear. Here, using yeast two-hybrid assays followed by biochemical binding experiments, we show that the region in CAPS1 consisting of the C-terminal half of the MHD1 with the corresponding C-terminal region can bind to syntaxin-1. Importantly, the binding mode of CAPS1 to syntaxin-1 is distinct from that of Munc13-1; CAPS1 binds to the full-length of cytoplasmic syntaxin-1 with preference to its "open" conformation, whereas Munc13-1 binds to the first 80 N-terminal residues of syntaxin-1. Unexpectedly, the majority of the MHD1 of CAPS1 is dispensable, whereas the C-terminal 69 residues are crucial for the binding to syntaxin-1. Functionally, a C-terminal truncation of 69 or 134 residues in CAPS1 abolishes its ability to reconstitute secretion in permeabilized PC12 cells. Our results reveal a novel mode of binding between CAPS1 and syntaxin-1, which play a crucial role in neurosecretion. We suggest that the distinct binding modes between CAPS1 and Munc13-1 can account for their non-redundant functions in neurosecretion. We also propose that the preferential binding of CAPS1 to open syntaxin-1 can contribute to the stabilization of the open state of syntaxin-1 during its transition from "closed" state to the SNARE complex formation.
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Affiliation(s)
- Leon Parsaud
- Division of Fundamental Neurobiology, University Health Network, Toronto, Ontario M5T 2S8, Canada
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McVeigh P, Atkinson L, Marks NJ, Mousley A, Dalzell JJ, Sluder A, Hammerland L, Maule AG. Parasite neuropeptide biology: Seeding rational drug target selection? Int J Parasitol Drugs Drug Resist 2012; 2:76-91. [PMID: 24533265 PMCID: PMC3862435 DOI: 10.1016/j.ijpddr.2011.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/25/2011] [Accepted: 10/28/2011] [Indexed: 01/16/2023]
Abstract
The rationale for identifying drug targets within helminth neuromuscular signalling systems is based on the premise that adequate nerve and muscle function is essential for many of the key behavioural determinants of helminth parasitism, including sensory perception/host location, invasion, locomotion/orientation, attachment, feeding and reproduction. This premise is validated by the tendency of current anthelmintics to act on classical neurotransmitter-gated ion channels present on helminth nerve and/or muscle, yielding therapeutic endpoints associated with paralysis and/or death. Supplementary to classical neurotransmitters, helminth nervous systems are peptide-rich and encompass associated biosynthetic and signal transduction components - putative drug targets that remain to be exploited by anthelmintic chemotherapy. At this time, no neuropeptide system-targeting lead compounds have been reported, and given that our basic knowledge of neuropeptide biology in parasitic helminths remains inadequate, the short-term prospects for such drugs remain poor. Here, we review current knowledge of neuropeptide signalling in Nematoda and Platyhelminthes, and highlight a suite of 19 protein families that yield deleterious phenotypes in helminth reverse genetics screens. We suggest that orthologues of some of these peptidergic signalling components represent appealing therapeutic targets in parasitic helminths.
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Affiliation(s)
- Paul McVeigh
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Louise Atkinson
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Nikki J. Marks
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Angela Mousley
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Johnathan J. Dalzell
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Ann Sluder
- Scynexis Inc., P.O. Box 12878, Research Triangle Park, NC 27709-2878, USA
| | | | - Aaron G. Maule
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
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Kumar GSS, Venugopal AK, Mahadevan A, Renuse S, Harsha HC, Sahasrabuddhe NA, Pawar H, Sharma R, Kumar P, Rajagopalan S, Waddell K, Ramachandra YL, Satishchandra P, Chaerkady R, Prasad TSK, Shankar K, Pandey A. Quantitative proteomics for identifying biomarkers for tuberculous meningitis. Clin Proteomics 2012. [PMID: 23198679 DOI: 10.1186/1559-0275-9-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED INTRODUCTION Tuberculous meningitis is a frequent extrapulmonary disease caused by Mycobacterium tuberculosis and is associated with high mortality rates and severe neurological sequelae. In an earlier study employing DNA microarrays, we had identified genes that were differentially expressed at the transcript level in human brain tissue from cases of tuberculous meningitis. In the current study, we used a quantitative proteomics approach to discover protein biomarkers for tuberculous meningitis. METHODS To compare brain tissues from confirmed cased of tuberculous meningitis with uninfected brain tissue, we carried out quantitative protein expression profiling using iTRAQ labeling and LC-MS/MS analysis of SCX fractionated peptides on Agilent's accurate mass QTOF mass spectrometer. RESULTS AND CONCLUSIONS Through this approach, we identified both known and novel differentially regulated molecules. Those described previously included signal-regulatory protein alpha (SIRPA) and protein disulfide isomerase family A, member 6 (PDIA6), which have been shown to be overexpressed at the mRNA level in tuberculous meningitis. The novel overexpressed proteins identified in our study included amphiphysin (AMPH) and neurofascin (NFASC) while ferritin light chain (FTL) was found to be downregulated in TBM. We validated amphiphysin, neurofascin and ferritin light chain using immunohistochemistry which confirmed their differential expression in tuberculous meningitis. Overall, our data provides insights into the host response in tuberculous meningitis at the molecular level in addition to providing candidate diagnostic biomarkers for tuberculous meningitis.
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Autistic-like behavioral phenotypes in a mouse model with copy number variation of the CAPS2/CADPS2 gene. FEBS Lett 2012; 587:54-9. [PMID: 23159942 DOI: 10.1016/j.febslet.2012.10.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/24/2012] [Accepted: 10/29/2012] [Indexed: 01/04/2023]
Abstract
Ca²⁺-dependent activator protein for secretion 2 (CAPS2 or CADPS2) facilitates secretion and trafficking of dense-core vesicles. Recent genome-wide association studies of autism have identified several microdeletions due to copy number variation (CNV) in one of the chromosome 7q31.32 alleles on which the locus for CAPS2 is located in autistic patients. To evaluate the biological significance of reducing CAPS2 copy number, we analyzed CAPS2 heterozygous mice. Our present findings suggest that adequate levels of CAPS2 protein are critical for normal brain development and behavior, and that allelic changes due to CNV may contribute to autistic symptoms in combination with deficits in other autism-associated genes.
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Kasai H, Takahashi N, Tokumaru H. Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis. Physiol Rev 2012; 92:1915-64. [DOI: 10.1152/physrev.00007.2012] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The dynamics of exocytosis are diverse and have been optimized for the functions of synapses and a wide variety of cell types. For example, the kinetics of exocytosis varies by more than five orders of magnitude between ultrafast exocytosis in synaptic vesicles and slow exocytosis in large dense-core vesicles. However, in all cases, exocytosis is mediated by the same fundamental mechanism, i.e., the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. It is often assumed that vesicles need to be docked at the plasma membrane and SNARE proteins must be preassembled before exocytosis is triggered. However, this model cannot account for the dynamics of exocytosis recently reported in synapses and other cells. For example, vesicles undergo exocytosis without prestimulus docking during tonic exocytosis of synaptic vesicles in the active zone. In addition, epithelial and hematopoietic cells utilize cAMP and kinases to trigger slow exocytosis of nondocked vesicles. In this review, we summarize the manner in which the diversity of exocytosis reflects the initial configurations of SNARE assembly, including trans-SNARE, binary-SNARE, unitary-SNARE, and cis-SNARE configurations. The initial SNARE configurations depend on the particular SNARE subtype (syntaxin, SNAP25, or VAMP), priming proteins (Munc18, Munc13, CAPS, complexin, or snapin), triggering proteins (synaptotagmins, Doc2, and various protein kinases), and the submembraneous cytomatrix, and they are the key to determining the kinetics of subsequent exocytosis. These distinct initial configurations will help us clarify the common SNARE assembly processes underlying exocytosis and membrane trafficking in eukaryotic cells.
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Affiliation(s)
- Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Noriko Takahashi
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Hiroshi Tokumaru
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
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Smith CJA, Bensing S, Burns C, Robinson PJ, Kasperlik-Zaluska AA, Scott RJ, Kämpe O, Crock PA. Identification of TPIT and other novel autoantigens in lymphocytic hypophysitis: immunoscreening of a pituitary cDNA library and development of immunoprecipitation assays. Eur J Endocrinol 2012; 166:391-8. [PMID: 22193973 PMCID: PMC3290121 DOI: 10.1530/eje-11-1015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Lymphocytic hypophysitis is an organ-specific autoimmune disease of the pituitary gland. A specific and sensitive serological test currently does not exist to aid in the diagnosis. OBJECTIVE To identify target autoantigens in lymphocytic hypophysitis and develop a diagnostic assay for these proteins. DESIGN/METHODS A pituitary cDNA expression library was immunoscreened using sera from four patients with lymphocytic hypophysitis. Relevant cDNA clones from screening, along with previously identified autoantigens pituitary gland-specific factor 1a and 2 (PGSF1a and PGSF2) and neuron-specific enolase (NSE) were tested in an in vitro transcription and translation immunoprecipitation assay. The corticotroph-specific transcription factor, TPIT, was investigated separately as a candidate autoantigen. RESULTS Significantly positive autoantibody reactivity against TPIT was found in 9/86 hypophysitis patients vs 1/90 controls (P = 0.018). The reactivity against TPIT was not specific for lymphocytic hypophysitis with autoantibodies detectable in the sera from patients with other autoimmune endocrine diseases. Autoantibodies were also detected against chromodomain-helicase-DNA binding protein 8, presynaptic cytomatrix protein (piccolo), Ca(2+)-dependent secretion activator, PGSF2 and NSE in serum samples from patients with lymphocytic hypophysitis, but at a frequency that did not differ from healthy controls. Importantly, 8/86 patients with lymphocytic hypophysitis had autoantibodies against any two autoantigens in comparison with 0/90 controls (P = 0.0093). CONCLUSIONS TPIT, a corticotroph-specific transcription factor, was identified as a target autoantigen in 10.5% of patients with lymphocytic hypophysitis. Further autoantigens related to vesicle processing were also identified as potential autoantigens with different immunoreactivity patterns in patients and controls.
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Affiliation(s)
- Casey Jo Anne Smith
- Department of Paediatric Endocrinology and Diabetes, Faculty of HealthLocked Bag 1, Newcastle Mail Centre, John Hunter Children's Hospital, University of NewcastleNewcastle, 2310, New South WalesAustralia
- Department of Medical SciencesUppsala UniversityUppsalaSweden
| | - Sophie Bensing
- Department of Medical SciencesUppsala UniversityUppsalaSweden
- Department of Molecular Medicine and SurgeryKarolinska InstitutetStockholmSweden
| | - Christine Burns
- Division of Genetics, Hunter Area Pathology ServiceJohn Hunter HospitalNewcastle, New South WalesAustralia
| | - Phillip J Robinson
- Cell Signalling UnitChildren's Medical Research InstituteWestmead, New South WalesAustralia
| | - Anna A Kasperlik-Zaluska
- Department of EndocrinologyCentre for Postgraduate Medical Education, Bielanski HospitalWarsawPoland
| | - Rodney J Scott
- Division of Genetics, Hunter Area Pathology ServiceJohn Hunter HospitalNewcastle, New South WalesAustralia
- Discipline of Medical Genetics, Faculty of HealthUniversity of Newcastle and the Hunter Medical Research Institute, New Lambton HeightsNewcastle, New South WalesAustralia
| | - Olle Kämpe
- Department of Medical SciencesUppsala UniversityUppsalaSweden
| | - Patricia A Crock
- Department of Paediatric Endocrinology and Diabetes, Faculty of HealthLocked Bag 1, Newcastle Mail Centre, John Hunter Children's Hospital, University of NewcastleNewcastle, 2310, New South WalesAustralia
- (Correspondence should be addressed to P A Crock; )
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Abstract
Synaptic transmission is amongst the most sophisticated and tightly controlled biological phenomena in higher eukaryotes. In the past few decades, tremendous progress has been made in our understanding of the molecular mechanisms underlying multiple facets of neurotransmission, both pre- and postsynaptically. Brought under the spotlight by pioneer studies in the areas of secretion and signal transduction, phosphoinositides and their metabolizing enzymes have been increasingly recognized as key protagonists in fundamental aspects of neurotransmission. Not surprisingly, dysregulation of phosphoinositide metabolism has also been implicated in synaptic malfunction associated with a variety of brain disorders. In the present chapter, we summarize current knowledge on the role of phosphoinositides at the neuronal synapse and highlight some of the outstanding questions in this research field.
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Affiliation(s)
- Samuel G Frere
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, 630 West 168th Street, P&S 12-420C, 10032, New York, USA
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Sadakata T, Sekine Y, Oka M, Itakura M, Takahashi M, Furuichi T. Calcium-dependent activator protein for secretion 2 interacts with the class II ARF small GTPases and regulates dense-core vesicle trafficking. FEBS J 2011; 279:384-94. [PMID: 22111578 DOI: 10.1111/j.1742-4658.2011.08431.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The Ca(2+) -dependent activator protein for secretion (CAPS) family consists of two members (CAPS1 and CAPS2) and regulates the exocytosis of catecholamine-containing or neuropeptide-containing dense-core vesicles (DCVs) at secretion sites such as nerve terminals. A large fraction of CAPS1, however, is localized in the cell soma, and we have recently shown the possible involvement of somal CAPS1 in DCV trafficking in the trans-Golgi network. CAPS1 and CAPS2 are differentially expressed in various regions of the mouse brain but exhibit similar expression patterns in other tissues, such as the spleen. Thus, in the present study we analyzed whether CAPS2 displays similar subcellular localization and functional roles in the cell soma as CAPS1. We found that somal CAPS2 is associated with the Golgi membrane, and mediates binding and recruitment of the GDP-bound form of ARF4 and ARF5 (members of the membrane-trafficking small GTPase family) to the Golgi membrane. CAPS2 knockdown and overexpression of CAPS2-binding-deficient ARF4/ARF5 both induced accumulation of the DCV resident protein chromogranin A around the Golgi apparatus. CAPS2 knockout mice have dilated trans-Golgi structures when viewed by electron microscopy. These results for CAPS2 strongly support our idea that the CAPS family proteins exert dual roles in DCV trafficking, mediating trafficking at both the secretion site for exocytosis and at the Golgi complex for biogenesis.
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Affiliation(s)
- Tetsushi Sadakata
- Advanced Scientific Research Leaders Development Unit, Gunma University, Japan
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Degeneracy and neuromodulation among thermosensory neurons contribute to robust thermosensory behaviors in Caenorhabditis elegans. J Neurosci 2011; 31:11718-27. [PMID: 21832201 DOI: 10.1523/jneurosci.1098-11.2011] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Animals must ensure that they can execute behaviors important for physiological homeostasis under constantly changing environmental conditions. The neural mechanisms that regulate this behavioral robustness are not well understood. The nematode Caenorhabditis elegans thermoregulates primarily via modulation of navigation behavior. Upon encountering temperatures higher than its cultivation temperature (T(c)), C. elegans exhibits negative thermotaxis toward colder temperatures using a biased random walk strategy. We find that C. elegans exhibits robust negative thermotaxis bias under conditions of varying T(c) and temperature ranges. By cell ablation and cell-specific rescue experiments, we show that the ASI chemosensory neurons are newly identified components of the thermosensory circuit, and that different combinations of ASI and the previously identified AFD and AWC thermosensory neurons are necessary and sufficient under different conditions to execute a negative thermotaxis strategy. ASI responds to temperature stimuli within a defined operating range defined by T(c), and signaling from AFD regulates the bounds of this operating range, suggesting that neuromodulation among thermosensory neurons maintains coherence of behavioral output. Our observations demonstrate that a negative thermotaxis navigational strategy can be generated via different combinations of thermosensory neurons acting degenerately, and emphasize the importance of defining context when analyzing neuronal contributions to a behavior.
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UNC-73/trio RhoGEF-2 activity modulates Caenorhabditis elegans motility through changes in neurotransmitter signaling upstream of the GSA-1/Galphas pathway. Genetics 2011; 189:137-51. [PMID: 21750262 DOI: 10.1534/genetics.111.131227] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Rho-family GTPases play regulatory roles in many fundamental cellular processes. Caenorhabditis elegans UNC-73 RhoGEF isoforms function in axon guidance, cell migration, muscle arm extension, phagocytosis, and neurotransmission by activating either Rac or Rho GTPase subfamilies. Multiple differentially expressed UNC-73 isoforms contain a Rac-specific RhoGEF-1 domain, a Rho-specific RhoGEF-2 domain, or both domains. The UNC-73E RhoGEF-2 isoform is activated by the G-protein subunit Gαq and is required for normal rates of locomotion; however, mechanisms of UNC-73 and Rho pathway regulation of locomotion are not clear. To better define UNC-73 function in the regulation of motility we used cell-specific and inducible promoters to examine the temporal and spatial requirements of UNC-73 RhoGEF-2 isoform function in mutant rescue experiments. We found that UNC-73E acts within peptidergic neurons of mature animals to regulate locomotion rate. Although unc-73 RhoGEF-2 mutants have grossly normal synaptic morphology and weak resistance to the acetylcholinesterase inhibitor aldicarb, they are significantly hypersensitive to the acetylcholine receptor agonist levamisole, indicating alterations in acetylcholine neurotransmitter signaling. Consistent with peptidergic neuron function, unc-73 RhoGEF-2 mutants exhibit a decreased level of neuropeptide release from motor neuron dense core vesicles (DCVs). The unc-73 locomotory phenotype is similar to those of rab-2 and unc-31, genes with distinct roles in the DCV-mediated secretory pathway. We observed that constitutively active Gαs pathway mutations, which compensate for DCV-mediated signaling defects, rescue unc-73 RhoGEF-2 and rab-2 lethargic movement phenotypes. Together, these data suggest UNC-73 RhoGEF-2 isoforms are required for proper neurotransmitter signaling and may function in the DCV-mediated neuromodulatory regulation of locomotion rate.
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Neuropeptide gene families in Caenorhabditis elegans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 692:98-137. [PMID: 21189676 DOI: 10.1007/978-1-4419-6902-6_6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Neuropeptides are short sequences ofamino acids that function in all multicellular organisms to communicate information between cells. The first sequence ofa neuropeptide was reported in 1970' and the number of identified neuropeptides remained relatively small until the 1990s when the DNA sequence of multiple genomes revealed treasure troves ofinformation. Byblasting away at the genome, gene families, the sizes ofwhich were previously unknown, could now be determined. This information has led to an exponential increase in the number of putative neuropeptides and their respective gene families. The molecular biology age greatly benefited the neuropeptide field in the nematode Caenorhabditis elegans. Its genome was among the first to be sequenced and this allowed us the opportunity to screen the genome for neuropeptide genes. Initially, the screeningwas slow, as the Genefinder and BLAST programs had difficulty identifying small genes and peptides. However, as the bioinformatics programs improved, the extent of the neuropeptide gene families in C. elegans gradually emerged.
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Lindsay TH, Thiele TR, Lockery SR. Optogenetic analysis of synaptic transmission in the central nervous system of the nematode Caenorhabditis elegans. Nat Commun 2011; 2:306. [PMID: 21556060 PMCID: PMC3935721 DOI: 10.1038/ncomms1304] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 04/06/2011] [Indexed: 02/06/2023] Open
Abstract
A reliable method for recording evoked synaptic events in identified neurons in Caenorhabditis elegans would greatly accelerate our understanding of its nervous system at the molecular, cellular and network levels. Here we describe a method for recording synaptic currents and potentials from identified neurons in nearly intact worms. Dissection and exposure of postsynaptic neurons is facilitated by microfabricated agar substrates, and ChannelRhodopsin-2 is used to stimulate presynaptic neurons. We used the method to analyse functional connectivity between a polymodal nociceptor and a command neuron that initiates a stochastic escape behaviour. We find that escape probability mirrors the time course of synaptic current in the command neuron. Moreover, synaptic input increases smoothly as stimulus strength is increased, suggesting that the overall input-output function of the connection is graded. We propose a model in which the energetic cost of escape behaviours in C. elegans is tuned to the intensity of the threat.
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Affiliation(s)
- Theodore H Lindsay
- Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403, USA
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Sadakata T, Shinoda Y, Sekine Y, Saruta C, Itakura M, Takahashi M, Furuichi T. Interaction of calcium-dependent activator protein for secretion 1 (CAPS1) with the class II ADP-ribosylation factor small GTPases is required for dense-core vesicle trafficking in the trans-Golgi network. J Biol Chem 2010; 285:38710-9. [PMID: 20921225 PMCID: PMC2992304 DOI: 10.1074/jbc.m110.137414] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 09/30/2010] [Indexed: 11/06/2022] Open
Abstract
Ca(2+)-dependent activator protein for secretion (CAPS) regulates exocytosis of catecholamine- or neuropeptide-containing dense-core vesicles (DCVs) at secretion sites, such as nerve terminals. However, large amounts of CAPS protein are localized in the cell soma, and the role of somal CAPS protein remains unclear. The present study shows that somal CAPS1 plays an important role in DCV trafficking in the trans-Golgi network. The anti-CAPS1 antibody appeared to pull down membrane fractions, including many Golgi-associated proteins, such as ADP-ribosylation factor (ARF) small GTPases. Biochemical analyses of the protein-protein interaction showed that CAPS1 interacted specifically with the class II ARF4/ARF5, but not with other classes of ARFs, via the pleckstrin homology domain in a GDP-bound ARF form-specific manner. The pleckstrin homology domain of CAPS1 showed high affinity for the Golgi membrane, thereby recruiting ARF4/ARF5 to the Golgi complex. Knockdown of either CAPS1 or ARF4/ARF5 expression caused accumulation of chromogranin, a DCV marker protein, in the Golgi, thereby reducing its DCV secretion. In addition, the overexpression of CAPS1 binding-deficient ARF5 mutants induced aberrant chromogranin accumulation in the Golgi and consequently reduced its DCV secretion. These findings implicate a functional role for CAPS1 protein in the soma, a major subcellular localization site of CAPS1 in many cell types, in regulating DCV trafficking in the trans-Golgi network; this activity occurs via protein-protein interaction with ARF4/ARF5 in a GDP-dependent manner.
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Affiliation(s)
- Tetsushi Sadakata
- From the Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Japan Science and Technology Agency/CREST, Kawaguchi, Saitama 332-0012, Japan, and
| | - Yo Shinoda
- From the Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Japan Science and Technology Agency/CREST, Kawaguchi, Saitama 332-0012, Japan, and
| | - Yukiko Sekine
- From the Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Chihiro Saruta
- From the Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Makoto Itakura
- Japan Science and Technology Agency/CREST, Kawaguchi, Saitama 332-0012, Japan, and
- the Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa 228-8555, Japan
| | - Masami Takahashi
- Japan Science and Technology Agency/CREST, Kawaguchi, Saitama 332-0012, Japan, and
- the Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa 228-8555, Japan
| | - Teiichi Furuichi
- From the Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Japan Science and Technology Agency/CREST, Kawaguchi, Saitama 332-0012, Japan, and
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Liu Y, Schirra C, Edelmann L, Matti U, Rhee J, Hof D, Bruns D, Brose N, Rieger H, Stevens DR, Rettig J. Two distinct secretory vesicle-priming steps in adrenal chromaffin cells. ACTA ACUST UNITED AC 2010; 190:1067-77. [PMID: 20855507 PMCID: PMC3101601 DOI: 10.1083/jcb.201001164] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The calcium-dependent activator proteins for secretion, CAPS1 and CAPS2, facilitate syntaxin opening during synaptic vesicle priming. Priming of large dense-core vesicles (LDCVs) is a Ca2+-dependent step by which LDCVs enter a release-ready pool, involving the formation of the soluble N-ethyl-maleimide sensitive fusion protein attachment protein (SNAP) receptor complex consisting of syntaxin, SNAP-25, and synaptobrevin. Using mice lacking both isoforms of the calcium-dependent activator protein for secretion (CAPS), we show that LDCV priming in adrenal chromaffin cells entails two distinct steps. CAPS is required for priming of the readily releasable LDCV pool and sustained secretion in the continued presence of high Ca2+ concentrations. Either CAPS1 or CAPS2 can rescue secretion in cells lacking both CAPS isoforms. Furthermore, the deficit in the readily releasable LDCV pool resulting from CAPS deletion is reversed by a constitutively open form of syntaxin but not by Munc13-1, a priming protein that facilitates the conversion of syntaxin to the open conformation. Our data indicate that CAPS functions downstream of Munc13s but also interacts functionally with Munc13s in the LDCV-priming process.
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Affiliation(s)
- Yuanyuan Liu
- Institut für Physiologie, Universität des Saarlandes, 66421 Homburg, Germany
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Sadakata T, Furuichi T. Ca2+-dependent activator protein for secretion 2 and autistic-like phenotypes. Neurosci Res 2010; 67:197-202. [DOI: 10.1016/j.neures.2010.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 11/16/2022]
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