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Grochowska KM, Gomes GM, Raman R, Kaushik R, Sosulina L, Kaneko H, Oelschlegel AM, Yuanxiang P, Reyes‐Resina I, Bayraktar G, Samer S, Spilker C, Woo MS, Morawski M, Goldschmidt J, Friese MA, Rossner S, Navarro G, Remy S, Reissner C, Karpova A, Kreutz MR. Jacob-induced transcriptional inactivation of CREB promotes Aβ-induced synapse loss in Alzheimer's disease. EMBO J 2023; 42:e112453. [PMID: 36594364 PMCID: PMC9929644 DOI: 10.15252/embj.2022112453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 01/04/2023] Open
Abstract
Synaptic dysfunction caused by soluble β-amyloid peptide (Aβ) is a hallmark of early-stage Alzheimer's disease (AD), and is tightly linked to cognitive decline. By yet unknown mechanisms, Aβ suppresses the transcriptional activity of cAMP-responsive element-binding protein (CREB), a master regulator of cell survival and plasticity-related gene expression. Here, we report that Aβ elicits nucleocytoplasmic trafficking of Jacob, a protein that connects a NMDA-receptor-derived signalosome to CREB, in AD patient brains and mouse hippocampal neurons. Aβ-regulated trafficking of Jacob induces transcriptional inactivation of CREB leading to impairment and loss of synapses in mouse models of AD. The small chemical compound Nitarsone selectively hinders the assembly of a Jacob/LIM-only 4 (LMO4)/ Protein phosphatase 1 (PP1) signalosome and thereby restores CREB transcriptional activity. Nitarsone prevents impairment of synaptic plasticity as well as cognitive decline in mouse models of AD. Collectively, the data suggest targeting Jacob protein-induced CREB shutoff as a therapeutic avenue against early synaptic dysfunction in AD.
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Affiliation(s)
- Katarzyna M Grochowska
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Guilherme M Gomes
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Rajeev Raman
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Rahul Kaushik
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Liudmila Sosulina
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Hiroshi Kaneko
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | | | - PingAn Yuanxiang
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | | | - Gonca Bayraktar
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Sebastian Samer
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Christina Spilker
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Marcel S Woo
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Markus Morawski
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Jürgen Goldschmidt
- Department of Systems Physiology of Learning and MemoryLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Manuel A Friese
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Steffen Rossner
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Gemma Navarro
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food ScienceUniversity of BarcelonaBarcelonaSpain
- Institut de Neurociències de la Universitat de BarcelonaBarcelonaSpain
| | - Stefan Remy
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Carsten Reissner
- Institute of Anatomy and Molecular NeurobiologyWestfälische Wilhelms‐UniversityMünsterGermany
| | - Anna Karpova
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Michael R Kreutz
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
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Mikhaylova M, Bär J, van Bommel B, Schätzle P, YuanXiang P, Raman R, Hradsky J, Konietzny A, Loktionov EY, Reddy PP, Lopez-Rojas J, Spilker C, Kobler O, Raza SA, Stork O, Hoogenraad CC, Kreutz MR. Caldendrin Directly Couples Postsynaptic Calcium Signals to Actin Remodeling in Dendritic Spines. Neuron 2018; 97:1110-1125.e14. [PMID: 29478916 DOI: 10.1016/j.neuron.2018.01.046] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/18/2017] [Accepted: 01/26/2018] [Indexed: 11/19/2022]
Abstract
Compartmentalization of calcium-dependent plasticity allows for rapid actin remodeling in dendritic spines. However, molecular mechanisms for the spatio-temporal regulation of filamentous actin (F-actin) dynamics by spinous Ca2+-transients are still poorly defined. We show that the postsynaptic Ca2+ sensor caldendrin orchestrates nano-domain actin dynamics that are essential for actin remodeling in the early phase of long-term potentiation (LTP). Steep elevation in spinous [Ca2+]i disrupts an intramolecular interaction of caldendrin and allows cortactin binding. The fast on and slow off rate of this interaction keeps cortactin in an active conformation, and protects F-actin at the spine base against cofilin-induced severing. Caldendrin gene knockout results in higher synaptic actin turnover, altered nanoscale organization of spinous F-actin, defects in structural spine plasticity, LTP, and hippocampus-dependent learning. Collectively, the data indicate that caldendrin-cortactin directly couple [Ca2+]i to preserve a minimal F-actin pool that is required for actin remodeling in the early phase of LTP.
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Affiliation(s)
- Marina Mikhaylova
- Emmy Noether Group "Neuronal Protein Transport," Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany; RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany; Cell Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands.
| | - Julia Bär
- Emmy Noether Group "Neuronal Protein Transport," Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany; RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Bas van Bommel
- Emmy Noether Group "Neuronal Protein Transport," Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Philipp Schätzle
- Cell Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - PingAn YuanXiang
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Rajeev Raman
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Johannes Hradsky
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Anja Konietzny
- Emmy Noether Group "Neuronal Protein Transport," Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Egor Y Loktionov
- State Lab for Photon Energetics, Bauman Moscow State University, Moscow 105005, Russia
| | | | - Jeffrey Lopez-Rojas
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Christina Spilker
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany
| | - Oliver Kobler
- Combinatorial Neuroimaging Core Facility (CNI), Leibniz Institute for Neurobiology, Magdeburg 39118, Germany
| | - Syed Ahsan Raza
- Institute of Biology, Otto von Guericke University, Magdeburg 39120, Germany
| | - Oliver Stork
- Institute of Biology, Otto von Guericke University, Magdeburg 39120, Germany
| | - Casper C Hoogenraad
- Cell Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Michael R Kreutz
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg 39118, Germany; Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany.
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Spilker C, Grochowska KM, Kreutz MR. What do we learn from the murine Jacob/Nsmf gene knockout for human disease? Rare Dis 2016; 4:e1241361. [PMID: 27803842 PMCID: PMC5070631 DOI: 10.1080/21675511.2016.1241361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/05/2016] [Accepted: 09/21/2016] [Indexed: 02/08/2023] Open
Abstract
Mutations in the NSMF gene have been related to Kallmann syndrome. Conflicting results have been reported on the subcellular localization of Jacob/NELF, the protein encoded by the NSMF gene. Some reports indicate an extracellular localization and a function as a guidance molecule for migration of GnRH-positive neurons from the olfactory placode to the hypothalamus. Other studies have shown protein transport of Jacob from synapse-to-nucleus and indicate a role of the protein in neuronal activity-dependent gene expression. A recent publication casts doubts on a major role of Jacob/NELF in Kallmann syndrome and neuronal migration of GnRH-positive neurons during early development. Instead a murine NSMF gene knockout results in hippocampal dysplasia, impaired BDNF-signaling during dendritogenesis, and phenotypes related to the lack of BDNF-induced nuclear import of Jacob in early postnatal development.
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Affiliation(s)
- Christina Spilker
- RG Neuroplasticity, Leibniz-Institute for Neurobiology , Magdeburg, Germany
| | | | - Michael R Kreutz
- RG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg, Germany; Leibniz Group "Dendritic Organelles and Synaptic Function", Hamburg, Germany
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Spilker C, Nullmeier S, Grochowska KM, Schumacher A, Butnaru I, Macharadze T, Gomes GM, Yuanxiang P, Bayraktar G, Rodenstein C, Geiseler C, Kolodziej A, Lopez-Rojas J, Montag D, Angenstein F, Bär J, D’Hanis W, Roskoden T, Mikhaylova M, Budinger E, Ohl FW, Stork O, Zenclussen AC, Karpova A, Schwegler H, Kreutz MR. A Jacob/Nsmf Gene Knockout Results in Hippocampal Dysplasia and Impaired BDNF Signaling in Dendritogenesis. PLoS Genet 2016; 12:e1005907. [PMID: 26977770 PMCID: PMC4792503 DOI: 10.1371/journal.pgen.1005907] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 02/08/2016] [Indexed: 11/18/2022] Open
Abstract
Jacob, the protein encoded by the Nsmf gene, is involved in synapto-nuclear signaling and docks an N-Methyl-D-Aspartate receptor (NMDAR)-derived signalosome to nuclear target sites like the transcription factor cAMP-response-element-binding protein (CREB). Several reports indicate that mutations in NSMF are related to Kallmann syndrome (KS), a neurodevelopmental disorder characterized by idiopathic hypogonadotropic hypogonadism (IHH) associated with anosmia or hyposmia. It has also been reported that a protein knockdown results in migration deficits of Gonadotropin-releasing hormone (GnRH) positive neurons from the olfactory bulb to the hypothalamus during early neuronal development. Here we show that mice that are constitutively deficient for the Nsmf gene do not present phenotypic characteristics related to KS. Instead, these mice exhibit hippocampal dysplasia with a reduced number of synapses and simplification of dendrites, reduced hippocampal long-term potentiation (LTP) at CA1 synapses and deficits in hippocampus-dependent learning. Brain-derived neurotrophic factor (BDNF) activation of CREB-activated gene expression plays a documented role in hippocampal CA1 synapse and dendrite formation. We found that BDNF induces the nuclear translocation of Jacob in an NMDAR-dependent manner in early development, which results in increased phosphorylation of CREB and enhanced CREB-dependent Bdnf gene transcription. Nsmf knockout (ko) mice show reduced hippocampal Bdnf mRNA and protein levels as well as reduced pCREB levels during dendritogenesis. Moreover, BDNF application can rescue the morphological deficits in hippocampal pyramidal neurons devoid of Jacob. Taken together, the data suggest that the absence of Jacob in early development interrupts a positive feedback loop between BDNF signaling, subsequent nuclear import of Jacob, activation of CREB and enhanced Bdnf gene transcription, ultimately leading to hippocampal dysplasia.
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Affiliation(s)
- Christina Spilker
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Sven Nullmeier
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | | | - Anne Schumacher
- Department of Experimental Obstetrics and Gynaecology, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Ioana Butnaru
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Tamar Macharadze
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Guilherme M. Gomes
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - PingAn Yuanxiang
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Gonca Bayraktar
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Carolin Rodenstein
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Carolin Geiseler
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Angela Kolodziej
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Jeffrey Lopez-Rojas
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Dirk Montag
- Special Laboratory Neurogenetics, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Frank Angenstein
- Functional Neuroimaging Group, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), and Special Laboratory for Noninvasive Brain Imaging, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Julia Bär
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology, ZMNH, Emmy-Noether Group 'Neuronal Protein Transport', Hamburg, Germany
| | - Wolfgang D’Hanis
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Thomas Roskoden
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Marina Mikhaylova
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology, ZMNH, Emmy-Noether Group 'Neuronal Protein Transport', Hamburg, Germany
| | - Eike Budinger
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Frank W. Ohl
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Oliver Stork
- Institute of Biology, Otto von Guericke University, Magdeburg, Germany
| | - Ana C. Zenclussen
- Department of Experimental Obstetrics and Gynaecology, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Anna Karpova
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Herbert Schwegler
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Michael R. Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology, ZMNH, Leibniz Group 'Dendritic Organelles and Synaptic Function', Hamburg, Germany
- * E-mail:
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Reddy PP, Raghuram V, Hradsky J, Spilker C, Chakraborty A, Sharma Y, Mikhaylova M, Kreutz MR. Molecular dynamics of the neuronal EF-hand Ca2+-sensor Caldendrin. PLoS One 2014; 9:e103186. [PMID: 25058677 PMCID: PMC4110014 DOI: 10.1371/journal.pone.0103186] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/29/2014] [Indexed: 11/18/2022] Open
Abstract
Caldendrin, L- and S-CaBP1 are CaM-like Ca2+-sensors with different N-termini that arise from alternative splicing of the Caldendrin/CaBP1 gene and that appear to play an important role in neuronal Ca2+-signaling. In this paper we show that Caldendrin is abundantly present in brain while the shorter splice isoforms L- and S-CaBP1 are not detectable at the protein level. Caldendrin binds both Ca2+ and Mg2+ with a global Kd in the low µM range. Interestingly, the Mg2+-binding affinity is clearly higher than in S-CaBP1, suggesting that the extended N-terminus might influence Mg2+-binding of the first EF-hand. Further evidence for intra- and intermolecular interactions of Caldendrin came from gel-filtration, surface plasmon resonance, dynamic light scattering and FRET assays. Surprisingly, Caldendrin exhibits very little change in surface hydrophobicity and secondary as well as tertiary structure upon Ca2+-binding to Mg2+-saturated protein. Complex inter- and intramolecular interactions that are regulated by Ca2+-binding, high Mg2+- and low Ca2+-binding affinity, a rigid first EF-hand domain and little conformational change upon titration with Ca2+ of Mg2+-liganted protein suggest different modes of binding to target interactions as compared to classical neuronal Ca2+-sensors.
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Affiliation(s)
| | - Vijeta Raghuram
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Centre for Cellular and Molecular Biology, CSIR, Hyderabad, India
| | - Johannes Hradsky
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Christina Spilker
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | | | - Yogendra Sharma
- Centre for Cellular and Molecular Biology, CSIR, Hyderabad, India
| | - Marina Mikhaylova
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Cell Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Michael R. Kreutz
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- * E-mail:
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Karpova A, Mikhaylova M, Bera S, Bär J, Reddy P, Behnisch T, Rankovic V, Spilker C, Bethge P, Sahin J, Kaushik R, Zuschratter W, Kähne T, Naumann M, Gundelfinger E, Kreutz M. Encoding and Transducing the Synaptic or Extrasynaptic Origin of NMDA Receptor Signals to the Nucleus. Cell 2013; 152:1119-33. [DOI: 10.1016/j.cell.2013.02.002] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 12/11/2012] [Accepted: 02/01/2013] [Indexed: 10/27/2022]
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Schmeisser MJ, Ey E, Wegener S, Bockmann J, Stempel AV, Kuebler A, Janssen AL, Udvardi PT, Shiban E, Spilker C, Balschun D, Skryabin BV, Dieck ST, Smalla KH, Montag D, Leblond CS, Faure P, Torquet N, Le Sourd AM, Toro R, Grabrucker AM, Shoichet SA, Schmitz D, Kreutz MR, Bourgeron T, Gundelfinger ED, Boeckers TM. Autistic-like behaviours and hyperactivity in mice lacking ProSAP1/Shank2. Nature 2012; 486:256-60. [PMID: 22699619 DOI: 10.1038/nature11015] [Citation(s) in RCA: 463] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/08/2012] [Indexed: 01/22/2023]
Abstract
Autism spectrum disorders comprise a range of neurodevelopmental disorders characterized by deficits in social interaction and communication, and by repetitive behaviour. Mutations in synaptic proteins such as neuroligins, neurexins, GKAPs/SAPAPs and ProSAPs/Shanks were identified in patients with autism spectrum disorder, but the causative mechanisms remain largely unknown. ProSAPs/Shanks build large homo- and heteromeric protein complexes at excitatory synapses and organize the complex protein machinery of the postsynaptic density in a laminar fashion. Here we demonstrate that genetic deletion of ProSAP1/Shank2 results in an early, brain-region-specific upregulation of ionotropic glutamate receptors at the synapse and increased levels of ProSAP2/Shank3. Moreover, ProSAP1/Shank2(-/-) mutants exhibit fewer dendritic spines and show reduced basal synaptic transmission, a reduced frequency of miniature excitatory postsynaptic currents and enhanced N-methyl-d-aspartate receptor-mediated excitatory currents at the physiological level. Mutants are extremely hyperactive and display profound autistic-like behavioural alterations including repetitive grooming as well as abnormalities in vocal and social behaviours. By comparing the data on ProSAP1/Shank2(-/-) mutants with ProSAP2/Shank3αβ(-/-) mice, we show that different abnormalities in synaptic glutamate receptor expression can cause alterations in social interactions and communication. Accordingly, we propose that appropriate therapies for autism spectrum disorders are to be carefully matched to the underlying synaptopathic phenotype.
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Cosgrove J, Spilker C, Smith RA. . West J Med 2012; 344:e852-e852. [DOI: 10.1136/bmj.e852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
Small Rap guanosine-tri-phosphate (GTP)ases are crucially involved in many cellular processes, including cell proliferation, differentiation, survival, adhesion and movement. In line, it has been shown that Rap signalling is involved in various aspects of neuronal differentiation, like the establishment of neuronal polarity or axonal growth cone movement. Rap GTPases can be activated by a wide variety of external stimuli, and this is mediated by specific guanine nucleotide exchange factors (RapGEFs). Inactivation of RapGTP can be achieved with the aid of specific GTPase-activating proteins (RapGAPs). In the brain, the most prominent RapGAPs are Rap1GAP and those of the spine-associated RapGAP (SPAR) family. This latter family consists of three members (SPAR1-3), from which two of them, namely SPAR1 and 2, have been investigated in more detail. As such, the localization of RapGAPs is crucially important in regulating Rap signalling at various sites in the cell and, for both SPAR1 and 2, enrichment at synaptic sites has been demonstrated. In recent years particularly the role of SPAR1 in shaping dendritic spine morphology has attracted considerable interest. In this review we will summarize the described actions of different RapGAPs expressed in the brain, and we will focus in particular on the SPAR family members.
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Affiliation(s)
- Christina Spilker
- Project Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
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Dieterich DC, Karpova A, Mikhaylova M, Zdobnova I, König I, Landwehr M, Kreutz M, Smalla KH, Richter K, Landgraf P, Reissner C, Boeckers TM, Zuschratter W, Spilker C, Seidenbecher CI, Garner CC, Gundelfinger ED, Kreutz MR. Caldendrin-Jacob: a protein liaison that couples NMDA receptor signalling to the nucleus. PLoS Biol 2008; 6:e34. [PMID: 18303947 PMCID: PMC2253627 DOI: 10.1371/journal.pbio.0060034] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 01/03/2008] [Indexed: 11/18/2022] Open
Abstract
NMDA (N-methyl-D-aspartate) receptors and calcium can exert multiple and very divergent effects within neuronal cells, thereby impacting opposing occurrences such as synaptic plasticity and neuronal degeneration. The neuronal Ca2+ sensor Caldendrin is a postsynaptic density component with high similarity to calmodulin. Jacob, a recently identified Caldendrin binding partner, is a novel protein abundantly expressed in limbic brain and cerebral cortex. Strictly depending upon activation of NMDA-type glutamate receptors, Jacob is recruited to neuronal nuclei, resulting in a rapid stripping of synaptic contacts and in a drastically altered morphology of the dendritic tree. Jacob's nuclear trafficking from distal dendrites crucially requires the classical Importin pathway. Caldendrin binds to Jacob's nuclear localization signal in a Ca2+-dependent manner, thereby controlling Jacob's extranuclear localization by competing with the binding of Importin-alpha to Jacob's nuclear localization signal. This competition requires sustained synapto-dendritic Ca2+ levels, which presumably cannot be achieved by activation of extrasynaptic NMDA receptors, but are confined to Ca2+ microdomains such as postsynaptic spines. Extrasynaptic NMDA receptors, as opposed to their synaptic counterparts, trigger the cAMP response element-binding protein (CREB) shut-off pathway, and cell death. We found that nuclear knockdown of Jacob prevents CREB shut-off after extrasynaptic NMDA receptor activation, whereas its nuclear overexpression induces CREB shut-off without NMDA receptor stimulation. Importantly, nuclear knockdown of Jacob attenuates NMDA-induced loss of synaptic contacts, and neuronal degeneration. This defines a novel mechanism of synapse-to-nucleus communication via a synaptic Ca2+-sensor protein, which links the activity of NMDA receptors to nuclear signalling events involved in modelling synapto-dendritic input and NMDA receptor-induced cellular degeneration.
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Affiliation(s)
- Daniela C Dieterich
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Anna Karpova
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Marina Mikhaylova
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Irina Zdobnova
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Imbritt König
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Marco Landwehr
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Martin Kreutz
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Karl-Heinz Smalla
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Karin Richter
- Institute for Medical Neurobiology, Otto-von-Guericke University, Magdeburg, Germany
| | - Peter Landgraf
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Carsten Reissner
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Tobias M Boeckers
- Institute for Anatomy and Cell Biology, University of Ulm, Ulm, Germany
| | - Werner Zuschratter
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Christina Spilker
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Constanze I Seidenbecher
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Craig C Garner
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
| | - Eckart D Gundelfinger
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
| | - Michael R Kreutz
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry and Molecular Biology, Leibniz-Institute for Neurobiology, Magdeburg, Germany
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11
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Abstract
Spine-associated RapGAP 2 (SPAR2) is a novel GTPase activating protein (GAP) for the small GTPase Rap that shows significant sequence homology to SPAR, a synaptic RapGAP that was reported to regulate spine morphology in hippocampal neurons. SPAR2, like SPAR, interacts with the recently described synaptic scaffolding protein ProSAP-interacting protein (ProSAPiP), which in turn binds to the PDZ domain of ProSAP/Shank post-synaptic density proteins. In subcellular fractionation experiments, SPAR2 is enriched in synaptosomes and post-synaptic density fractions indicating that it is a synaptic protein. Furthermore, we could show using in vitro GAP assays that SPAR2 has GAP activity for Rap1 and Rap2. Expression in COS-7 cells, however, revealed different actin-binding properties of SPAR2 and SPAR. Additionally, over-expression of SPAR2 in cultured hippocampal neurons did not affect spine morphology as it was reported for SPAR. In situ hybridization studies also revealed a differential tissue distribution of SPAR and SPAR2 with SPAR2 transcripts being mainly expressed in cerebellar and hippocampal granule cells. Moreover, in the cerebellum SPAR2 is developmentally regulated with a peak of expression around the period of synapse formation. Our results imply that SPAR2 is a new RapGAP with specific functions in cerebellar and hippocampal granule cells.
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Affiliation(s)
- Christina Spilker
- Project Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.
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12
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Sandoval M, Sandoval R, Thomas U, Spilker C, Smalla KH, Falcon R, Marengo JJ, Calderón R, Saavedra V, Heumann R, Bronfman F, Garner CC, Gundelfinger ED, Wyneken U. Antagonistic effects of TrkB and p75NTRon NMDA receptor currents in post-synaptic densities transplanted into Xenopus oocytes. J Neurochem 2007; 101:1672-84. [PMID: 17394529 DOI: 10.1111/j.1471-4159.2007.04519.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are essential regulators of synaptic function in the adult CNS. A TrkB-mediated effect at excitatory synapses is enhancement of NMDA receptor (NMDA-R)-mediated currents. Recently, opposing effects of TrkB and the pan-neurotrophin receptor p75(NTR) on long-term synaptic depression and long-term potentiation have been reported in the hippocampus. To further study the regulation of NMDA-Rs by neurotrophin receptors in their native protein environment, we micro-transplanted rat forebrain post-synaptic densities (PSDs) into Xenopus oocytes. One-minute incubations of oocytes with BDNF led to dual effects on NMDA-R currents: either TrkB-dependent potentiation or TrkB-independent inhibition were observed. Pro-nerve growth factor, a ligand for p75(NTR) but not for TrkB, produced a reversible, dose-dependent, TrkB-independent and p75(NTR)-dependent inhibition of NMDA-Rs. Fractionation experiments showed that p75(NTR) is highly enriched in the PSD protein fraction. Immunoprecipitation and pull-down experiments further revealed that p75(NTR) is a core component of the PSD, where it interacts with the PDZ3 domain of the scaffolding protein SAP90/PSD-95. Our data provide striking evidence for a rapid inhibitory effect of p75(NTR) on NMDA-R currents that antagonizes TrkB-mediated NMDA-R potentiation. These opposing mechanisms might be present in a large proportion of forebrain synapses and may contribute importantly to synaptic plasticity.
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Affiliation(s)
- Mauricio Sandoval
- Laboratorio de Neurociencias, Universidad de Los Andes, Santiago, Chile
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13
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Wendholt D, Spilker C, Schmitt A, Dolnik A, Smalla KH, Proepper C, Bockmann J, Sobue K, Gundelfinger ED, Kreutz MR, Boeckers TM. ProSAP-interacting protein 1 (ProSAPiP1), a novel protein of the postsynaptic density that links the spine-associated Rap-Gap (SPAR) to the scaffolding protein ProSAP2/Shank3. J Biol Chem 2006; 281:13805-13816. [PMID: 16522626 DOI: 10.1074/jbc.m601101200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ProSAPs/Shanks are a family of proteins that have a major scaffolding function for components of the postsynaptic density (PSD) of excitatory brain synapses. Members of the family harbor a variety of domains for protein-protein interactions, one of which is a unique PDZ domain that differs significantly from those of other proteins. We have identified a novel binding partner for this PDZ domain, termed ProSAPiP1, that is highly enriched in the PSD and shares significant sequence homology with the PSD protein PSD-Zip70. Both molecules code for a Fez1 domain that can be found in a total of four related proteins. ProSAPiP1 is widely expressed in rat brain and co-localizes with ProSAP2/Shank3 in excitatory spines and synapses. ProSAP2/Shank3 co-immunoprecipitates with ProSAPiP1 but not with PSD-Zip70. Both proteins, however, bind and recruit SPAR to synapses with a central coiled-coil region that harbors a leucine zipper motif. This region is also responsible for homo- and heteromultimerization of ProSAPiP1 and PSD-Zip70. Thus, ProSAPiP1 and PSD-Zip70 are founders of a novel family of scaffolding proteins, the "Fezzins," which adds further complexity to the organization of the PSD protein network.
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Affiliation(s)
- Doreen Wendholt
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Christina Spilker
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Angelika Schmitt
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Anna Dolnik
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Karl-Heinz Smalla
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry/Molecular Biology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Christian Proepper
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Juergen Bockmann
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
| | - Kenji Sobue
- Department of Neuroscience, Osaka University School of Medicine, Suita, Osaka 565, Japan
| | - Eckart D Gundelfinger
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry/Molecular Biology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Michael R Kreutz
- AG Molecular Mechanisms of Plasticity, Department of Neurochemistry/Molecular Biology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany,.
| | - Tobias M Boeckers
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany.
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14
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Blazejczyk M, Wojda U, Sobczak A, Spilker C, Bernstein HG, Gundelfinger ED, Kreutz MR, Kuznicki J. Ca2+-independent binding and cellular expression profiles question a significant role of calmyrin in transduction of Ca2+-signals to Alzheimer's disease-related presenilin 2 in forebrain. Biochim Biophys Acta Mol Basis Dis 2005; 1762:66-72. [PMID: 16257512 DOI: 10.1016/j.bbadis.2005.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 09/27/2005] [Accepted: 09/27/2005] [Indexed: 01/06/2023]
Abstract
The interaction between the EF-hand Ca(2+)-binding protein calmyrin and presenilin 2 (PS2) has been suggested to play a role in Alzheimer's disease (AD). We now report that calmyrin binds specifically endogenous PS2 and not PS1. However, binding appears to be Ca(2+)-independent and calmyrin does not exhibit a Ca(2+)-dependent translocation to intracellular membranes as demonstrated in a Ca(2+)-myristoyl switch assay. Moreover, calmyrin is only present at very low levels in brain areas associated with the onset of AD. In rat, forebrain calmyrin is localized only in a subset of principal neurons, similarly as in human forebrain. Finally, subcellular fractionation demonstrates only a limited overlap of calmyrin and PS2 at neuronal membranes. We therefore conclude that calmyrin will not contribute significantly as a Ca(2+)-sensor that transduces Ca(2+)-signaling events to PS2 in forebrain.
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Affiliation(s)
- Magdalena Blazejczyk
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
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15
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Boeckers TM, Liedtke T, Spilker C, Dresbach T, Bockmann J, Kreutz MR, Gundelfinger ED. C-terminal synaptic targeting elements for postsynaptic density proteins ProSAP1/Shank2 and ProSAP2/Shank3. J Neurochem 2005; 92:519-24. [PMID: 15659222 DOI: 10.1111/j.1471-4159.2004.02910.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Synapses are specialized contact sites mediating communication between neurons. Synaptogenesis requires the specific assembly of protein clusters at both sides of the synaptic contact by mechanisms that are barely understood. We studied the synaptic targeting of multi-domain proteins of the ProSAP/Shank family thought to serve as master scaffolding molecules of the postsynaptic density. In contrast to Shank1, expression of green-fluorescent protein (GFP)-tagged ProSAP1/Shank2 and ProSAP2/Shank3 deletion constructs in hippocampal neurons revealed that their postsynaptic localization relies on the integrity of the C-termini. The shortest construct that was perfectly targeted to synaptic sites included the last 417 amino acids of ProSAP1/Shank2 and included the C-terminal sterile alpha motif (SAM) domain. Removal of 54 residues from the N-terminus of this construct resulted in a diffuse distribution in the cytoplasm. Altogether, our data delineate a hitherto unknown targeting signal in both ProSAP1/Shank2 and ProSAP2/Shank3 and provide evidence for an implication of these proteins and their close homologue, Shank1, in distinct molecular pathways.
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Affiliation(s)
- Tobias M Boeckers
- Institute of Anatomy and Cell Biology, University of Ulm, Albert Einstein Allee 11, 89081 Ulm, Germany.
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16
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Spilker C, Braunewell KH. Calcium–myristoyl switch, subcellular localization, and calcium-dependent translocation of the neuronal calcium sensor protein VILIP-3, and comparison with VILIP-1 in hippocampal neurons☆. Mol Cell Neurosci 2003; 24:766-78. [PMID: 14664824 DOI: 10.1016/s1044-7431(03)00242-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Neuronal calcium sensor (NCS) proteins including the subfamily of visinin-like-proteins (VILIPs) are involved in regulation of various signaling cascades. One molecular regulation mechanism is the calcium-myristoyl switch. VILIPs show a calcium-dependent membrane association in brain homogenates; however, differences in calcium-induced conformation changes and degree of membrane association are reported. Little is known about differences in the calcium-myristoyl switch in living cells leading to localization of VILIPs to distinct subcellular compartments. Therefore, we studied the calcium-dependent localization of green fluorescent protein (GFP)-tagged VILIP-3 in living cell lines and hippocampal neurons and compared it with that of GFP-VILIP-1. Interestingly, the observed fast and reversible calcium-myristoyl switch of VILIP-3-GFP and VILIP-1-GFP differed, e.g., in calcium-dependent translocation to Golgi membranes. Similarily, the calcium-dependent localization of endogenously expressed VILIP-3 and -1 in dendrites differed. Thus, VILIPs co-expressed in the same neuron show clear differences in calcium-dependent localization which may allow neurons a highly selective response to various calcium stimuli.
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Affiliation(s)
- Christina Spilker
- Signal Transduction Research Group, Neuroscience Research Center/Institute for Physiology of the Charite, Humboldt University Berlin, Tucholskystrasse 2, D-10117 Berlin, Germany
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17
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Dresbach T, Hempelmann A, Spilker C, tom Dieck S, Altrock WD, Zuschratter W, Garner CC, Gundelfinger ED. Functional regions of the presynaptic cytomatrix protein bassoon: significance for synaptic targeting and cytomatrix anchoring. Mol Cell Neurosci 2003; 23:279-91. [PMID: 12812759 DOI: 10.1016/s1044-7431(03)00015-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Exocytosis of neurotransmitter from synaptic vesicles is restricted to specialized sites of the presynaptic plasma membrane called active zones. A complex cytomatrix of proteins exclusively assembled at active zones, the CAZ, is thought to form a molecular scaffold that organizes neurotransmitter release sites. Here, we have analyzed synaptic targeting and cytomatrix association of Bassoon, a major scaffolding protein of the CAZ. By combining immunocytochemistry and transfection of cultured hippocampal neurons, we show that the central portion of Bassoon is crucially involved in synaptic targeting and CAZ association. An N-terminal region harbors a distinct capacity for N-myristoylation-dependent targeting to synaptic vesicle clusters, but is not incorporated into the CAZ. Our data provide the first experimental evidence for the existence of distinct functional regions in Bassoon and suggest that a centrally located CAZ targeting function may be complemented by an N-terminal capacity for targeting to membrane-bounded synaptic organelles.
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Affiliation(s)
- Thomas Dresbach
- Leibniz Institute for Neurobiology, Brenneckestrasse 6, D-39118, Magdeburg, Germany
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18
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Bernstein HG, Becker A, Keilhoff G, Spilker C, Gorczyca WA, Braunewell KH, Grecksch G. Brain region-specific changes in the expression of calcium sensor proteins after repeated applications of ketamine to rats. Neurosci Lett 2003; 339:95-8. [PMID: 12614903 DOI: 10.1016/s0304-3940(02)01482-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the cellular distribution of three calcium sensor proteins, visinin-like protein-1 (VILIP-1), VILIP-3, and hippocalcin, in different rat brain areas after repeated administration of the non-competitive N-methyl-D-aspartate receptor antagonist ketamine. In comparison to controls we observed an increase in the density of VILIP-1 immunoreactive (IR) hippocampal interneurons and presubicular nerve cells in ketamine treated rats, whereas the density of VILIP-1 expressing cells was decreased in the Nuc. accumbens of these rats. No alterations were seen in the distribution patterns of VILIP-3. The density of hippocalcin-expressing neurons was increased in the cingulate cortex of drug-treated rats. Our experiments show that repeated injections of subanesthetic doses of ketamine induce subtle changes in the cellular distribution of calcium sensor proteins which in part resemble those recently described in postmortem brains of human schizophrenics [Bernstein, H.-G., Braunewell, K.-H., Spilker, C., Danos, P., Baumann, B., Funke, S., Diekmann, S., Gundelfinger, E.D. and Bogerts, B., NeuroReport, 13 (2002) 393-396].
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Affiliation(s)
- Hans-Gert Bernstein
- Department of Psychiatry, University of Magdeburg, Leipziger Strasse 44, D-39120, Magdeburg, Germany.
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19
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Spilker C, Gundelfinger ED, Braunewell KH. Evidence for different functional properties of the neuronal calcium sensor proteins VILIP-1 and VILIP-3: from subcellular localization to cellular function. Biochim Biophys Acta 2002; 1600:118-27. [PMID: 12445467 DOI: 10.1016/s1570-9639(02)00452-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The visinin-like-proteins VILIP-1 and -3 are EF-hand calcium-binding proteins and belong to the family of neuronal calcium sensor (NCS) proteins. Members of this family are involved in the calcium-dependent regulation of signal transduction cascades mainly in the nervous system. VILIP-1 and VILIP-3 are expressed in different populations of neuronal cells. To gain insights into the different functional characteristics of VILIP-1 and -3, we have compared the localization of the proteins in intact cells and the calcium-dependent membrane association in subcellular fractions. Furthermore, we have investigated the different functional properties of the two proteins in activating cGMP signal pathways and have defined different sets of protein interaction partners. Our data indicate that VILIP-3, which is mainly expressed in Purkinje cells, and VILIP-1, which is expressed in granule cells in the cerebellum, show a different calcium-dependent subcellular localization, may activate different cellular signaling pathways, and thus have signaling functions which seem to be cell-type specific.
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Affiliation(s)
- C Spilker
- Signal Transduction Research Group, Leibniz Institute for Neurobiology, Germany
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20
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Spilker C, Dresbach T, Braunewell KH. Reversible translocation and activity-dependent localization of the calcium-myristoyl switch protein VILIP-1 to different membrane compartments in living hippocampal neurons. J Neurosci 2002; 22:7331-9. [PMID: 12196554 PMCID: PMC6757958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
Visinin-like protein-1 (VILIP-1) belongs to the family of neuronal calcium sensor (NCS) proteins, a neuronal subfamily of EF-hand [corrected] calcium-binding proteins that are myristoylated at their N termini. NCS proteins are discussed to play roles in calcium-dependent signal transduction of physiological and pathological processes in the CNS. The calcium-dependent membrane association, the so-called calcium-myristoyl switch, localizes NCS proteins to a distinct cellular signaling compartment and thus may be a critical mechanism for the coordinated regulation of signaling cascades. To study whether the biochemically defined calcium-myristoyl switch of NCS proteins can occur in living neuronal cells, the reversible and stimulus-dependent translocation of green fluorescent protein (GFP)-tagged VILIP-1 to subcellular targets was examined by fluorescence microscopy in transfected cell lines and hippocampal primary neurons. In transiently transfected NG108-15 and COS-7 cells, a translocation of diffusely distributed VILIP-1-GFP but not of myristoylation-deficient VILIP-1-GFP to the plasma membrane and to intracellular targets, such as Golgi membranes, occurred after raising the intracellular calcium concentration with a calcium ionophore. The observed calcium-dependent localization was completely reversed after depletion of intracellular calcium by EGTA. Interestingly, a fast and reversible translocation of VILIP-1-GFP and translocation of endogenous VILIP-1 to specialized membrane structures was also observed after a depolarizing stimulus or activation of glutamate receptors in hippocampal neurons. These results show for the first time the reversibility and stimulus-dependent occurrence of the calcium-myristoyl switch in living neurons, suggesting a physiological role as a signaling mechanism of NCS proteins, enabling them to activate specific targets localized in distinct membrane compartments.
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Affiliation(s)
- Christina Spilker
- Neuroscience Research Center-Institute for Physiology of the Charite, Humboldt University Berlin, Signal Transduction Research Group, D-10117 Berlin, Germany
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21
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Bernstein HG, Braunewell KH, Spilker C, Danos P, Baumann B, Funke S, Diekmann S, Gundelfinger ED, Bogerts B. Hippocampal expression of the calcium sensor protein visinin-like protein-1 in schizophrenia. Neuroreport 2002; 13:393-6. [PMID: 11930147 DOI: 10.1097/00001756-200203250-00006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hippocampal cytoarchitectural abnormalities may be part of the cerebral substrate of schizophrenia. Amongst the chemical components being abnormal in brains of schizophrenics are altered calcium concentrations and reduced expression of the neurotrophin receptor, trkB. We studied by immunohistochemical methods the distribution of visinin-like protein-1 (VILIP-1), which is a calcium sensor protein and at the same time a trkB mRNA binding protein, in hippocampi of nine schizophrenic patients and nine matched control subjects. In normal hippocampi VILIP-1 immunoreactivity was found in multiple pyramidal cells and interneurons. A portion of VILIP-1 immunoreactive interneurons co-express calretinin (60%) and parvalbumin (<10%). In schizophrenics fewer pyramidal cells but more interneurons were immunostained. Our data point to an involvement of the protein in the altered hippocampal circuitry in schizophrenia.
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Affiliation(s)
- Hans-Gert Bernstein
- Department of Psychiatry of the University Magdeburg, Leipziger Str. 44, D-39120, Germany
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22
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Braunewell KH, Brackmann M, Schaupp M, Spilker C, Anand R, Gundelfinger ED. Intracellular neuronal calcium sensor (NCS) protein VILIP-1 modulates cGMP signalling pathways in transfected neural cells and cerebellar granule neurones. J Neurochem 2001; 78:1277-86. [PMID: 11579136 DOI: 10.1046/j.1471-4159.2001.00506.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The family of intracellular neuronal calcium-sensors (NCS) belongs to the superfamily of EF-hand proteins. Family members have been shown by in vitro assays to regulate signal cascades in retinal photoreceptor cells. To study the functions of NCS proteins not expressed in photoreceptor cells we examined Visinin-like protein-1 (VILIP-1) effects on signalling pathways in living neural cells. Visinin-like protein-1 expression increased cGMP levels in transfected C6 and PC12 cells. Interestingly, in transfected PC12 cells stimulation was dependent on the subcellular localization of VILIP-1. In cells transfected with membrane-associated wild-type VILIP-1 particulate guanylyl cyclase (GC) was stimulated more strongly than soluble GC. In contrast, deletion of the N-terminal myristoylation site resulted in cytosolic localization of VILIP-1 and enhanced stimulation of soluble GC. To study the molecular mechanisms underlying GC stimulation VILIP-1 was examined to see if it can physically interact with GCs. A direct physical interaction of VILIP-1 with the recombinant catalytic domain of particulate GCs-A, B and with native GCs enriched from rat brain was observed in GST pull-down as well as in surface plasmon resonance interaction studies. Furthermore, following trituration of recombinant VILIP-1 protein into cerebellar granule cells the protein influenced only signalling by GC-B. Together with the observed colocalization of GC-B, but not GC-A, with VILIP-1 in cerebellar granule cells, these results suggest that VILIP-1 may be a physiological regulator of GC-B.
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Affiliation(s)
- K H Braunewell
- Signal Transduction Research Group, Leibniz Institute for Neurobiology Magdeburg, Germany.
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23
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Braunewell K, Riederer P, Spilker C, Gundelfinger ED, Bogerts B, Bernstein HG. Abnormal localization of two neuronal calcium sensor proteins, visinin-like proteins (vilips)-1 and -3, in neocortical brain areas of Alzheimer disease patients. Dement Geriatr Cogn Disord 2001; 12:110-6. [PMID: 11173883 DOI: 10.1159/000051244] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The anatomical distribution of the neuronal calcium sensor proteins visinin-like protein-1 and -3 (VILIP-1 and -3) was investigated in various neocortical areas of Alzheimer's disease (AD) patients and controls. In AD and normal brains their cellular localization was confined to pyramidal and non-pyramidal neurons. In AD brains the intracellular immunostaining for VILIP-1 and to a lesser extent for VILIP-3 was found to be reduced in comparison to controls. Also, significantly less VILIP-1-immunoreactive neurons were found in the temporal cortex of AD patients as compared to normal brains. Accordingly, Western blot analysis revealed that immunoreactivity for VILIP-1 is less concentrated in tissue extracts of the temporal cortex of AD patients compared to controls. Extracellularly, VILIP-1 and VILIP-3 immunoreactive material was detected in close association with typical pathologic hallmarks of AD such as dystrophic nerve cell processes, amorphous and neuritic plaques, and extracellular tangles. In control brains an extraneuronal localization of VILIP-1 or VILIP-3 was never observed. Our morphological and neurochemical findings point to an involvement of these two neuronal calcium sensor proteins in pathology and possibly pathophysiology of changed calcium homeostasis in AD.
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Affiliation(s)
- K Braunewell
- Leibniz Institute for Neurobiology, Department of Neurochemistry/Molecular Biology, Magdeburg, Germany
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24
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Spilker C, Richter K, Smalla KH, Manahan-Vaughan D, Gundelfinger ED, Braunewell KH. The neuronal EF-hand calcium-binding protein visinin-like protein-3 is expressed in cerebellar Purkinje cells and shows a calcium-dependent membrane association. Neuroscience 2000; 96:121-9. [PMID: 10683417 DOI: 10.1016/s0306-4522(99)00536-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visinin-like protein-3 is a member of the family of intracellular neuronal calcium sensors belonging to the superfamily of EF-hand proteins. Members of this family are involved in the calcium-dependent regulation of signal transduction cascades. To gain insights into the characteristics of visinin-like protein-3, we have generated specific antibodies against visinin-like protein-3 and determined the developmental and tissue distribution of the protein and its exact cellular and subcellular localization. Expression of visinin-like protein-3 protein appeared late in development mainly in the cerebellum. It is strongly expressed in cerebellar Purkinje cells. The protein expression results were further confirmed by in situ hybridization and compared with hippocalcin messenger RNA localization. Native cerebellar visinin-like protein-3 was shown to bind calcium and to associate in a calcium-dependent manner with membrane fractions during subcellular fractionation. Recombinant wild-type visinin-like protein-3 was shown to be N-terminally myristoylated in transfected cells. The membrane association was strongly reduced for the non-myristoylated mutant of visinin-like protein-3 in transfected cells. These results suggest that visinin-like protein-3, which is mainly expressed in Purkinje cells in vivo, shows a calcium-dependent association with cell membranes which is mediated by a calcium-myristoyl switch.
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Affiliation(s)
- C Spilker
- Leibniz Institute for Neurobiology, P.O. Box 1860, D-39008, Magdeburg, Germany
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Braunewell KH, Spilker C, Behnisch T, Gundelfinger ED. The neuronal calcium-sensor protein VILIP modulates cyclic AMP accumulation in stably transfected C6 glioma cells: amino-terminal myristoylation determines functional activity. J Neurochem 1997; 68:2129-39. [PMID: 9109541 DOI: 10.1046/j.1471-4159.1997.68052129.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
VILIP (visinin-like protein) is a member of the neuronal subfamily of EF-hand calcium sensor proteins. Members of this family are involved in the calcium-dependent regulation of the desensitization of signal cascades in retinal photoreceptors. To gain insight into the function of VILIP in cell signaling, we have transfected wild-type VILIP and mutant VILIP lacking the myristoylation consensus sequence into C6 glioma cells. Expression of wild-type VILIP did not significantly influence the desensitization of beta-adrenergic receptors, which are coupled to adenylyl cyclase in C6 cells. However, VILIP expression increased the beta-adrenergic receptor-stimulated cyclic AMP (cAMP) level in these cells severalfold. The stimulatory effect was also observed after direct stimulation of the adenylyl cyclase with forskolin, indicating that VILIP acts downstream of receptor and G protein in the beta-adrenergic signaling pathway in C6 cells. In contrast, the nonmyristoylated mutant of VILIP reduced cellular cAMP levels in C6 cells. Myristoylated wild-type VILIP was associated in a calcium-dependent manner with membrane fractions during subcellular fractionation, presumably owing to a calcium-myristoyl switch. In contrast, association of nonmyristoylated mutant VILIP with membranes was strongly reduced. Thus, myristoylation and most likely the calcium-dependent membrane association of VILIP are important prerequisites for the activating effect of wild-type VILIP on cAMP accumulation in C6 cells. These results suggest that VILIP acts as a calcium sensor molecule that modulates cell signaling cascades, possibly by direct or indirect regulation of adenylyl cyclase activity.
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Affiliation(s)
- K H Braunewell
- Department of Neurochemistry and Molecular Biology, Federal Institute for Neurobiology, Magdeburg, Germany
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Spilker C, Gundelfinger ED, Braunewell KH. Calcium- and myristoyl-dependent subcellular localization of the neuronal calcium-binding protein VILIP in transfected PC12 cells. Neurosci Lett 1997; 225:126-8. [PMID: 9147390 DOI: 10.1016/s0304-3940(97)00201-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Wild-type neuronal calcium-binding protein VILIP (visinin-like protein), and a myristoylation mutant of VILIP which lacks the consensus sequence for N-terminal myristoylation, have been stably transfected in PC12 cells. Immunocytochemical studies of VILIP-transfected PC12 cells have revealed the wild-type VILIP is strongly concentrated at the cell membrane, particularly at cell-cell contact sites, but is also distributed throughout the cytosol at moderate levels. In contrast, myristoylation-mutant VILIP shows a more even distribution, with significantly less association at cell-cell contact sites. Western blot analysis of subcellular fractions has shown that wild-type VILIP associates in a calcium-dependent manner with membrane fractions, whereas the myristoylation mutant only weakly associates with this fraction. Therefore, a calcium-myristoyl switch seems to be a major, but not sole determinant for the association of VILIP with membranes in living cells.
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Affiliation(s)
- C Spilker
- Department of Molecular Biology and Neurochemistry, Federal Institute for Neurobiology, Magdeburg, Germany
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Abstract
The purpose of this report is to present, in nontechnical terms, the purpose and history of the American College of Radiology and National Electrical Manufacturers Association (ACR-NEMA) Digital Imaging and Communications Standard (ACR-NEMA Standards Publication no. 300-1985), an explanation of what the standard is, the characteristics of the standard, possible applications of the standard, and ongoing standardization efforts. It is assumed that the reader has at least a basic understanding of the concepts and technologies described collectively as picture archiving and communication systems (PACS). For information on PACS, please refer to the NEMA PACS Primer and the list of suggested reading contained therein (for copies, write or call NEMA, 2101 L St, Suite 300, Washington, DC 20037, ATTN: Ms Cindy Fuscoe; telephone 202-457-1965).
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Affiliation(s)
- C Spilker
- Siemens Medical Systems, Inc., Iselin, NJ 08830
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Spilker C. Medical imaging: merging picture archives and communications. Inform 1987; 1:24-7. [PMID: 10281392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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