The Experts below are selected from a list of 18642 Experts worldwide ranked by ideXlab platform

Gina G. Turrigiano - One of the best experts on this subject based on the ideXlab platform.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

Richard L Huganir - One of the best experts on this subject based on the ideXlab platform.

  • serine racemase activation by Glutamate neurotransmission via Glutamate receptor interacting Protein and mediation of neuronal migration
    Proceedings of the National Academy of Sciences of the United States of America, 2005
    Co-Authors: Paul M Kim, Richard L Huganir, Roxanne K Barrow, Hiroyuki Aizawa, Peter S Kim, Alex S Huang, Sasrutha R Wickramasinghe, Amir H Kashani, Anirvan Ghosh
    Abstract:

    Serine racemase (SR), localized to astrocytic glia that ensheathe synapses, converts l-serine to d-serine, an endogenous ligand of the NMDA receptor. We report the activation of SR by Glutamate neurotransmission involving α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors via Glutamate receptor interacting Protein (GRIP) and the physiologic regulation of cerebellar granule cell migration by SR. GRIP physiologically binds SR, augmenting SR activity and d-serine release. GRIP infection of neonatal mouse cerebellum in vivo enhances granule cell migration. Selective degradation of d-serine by d-amino acid oxidase and pharmacologic inhibition of SR impede migration, whereas d-serine activates the process. Thus, in neuronal migration, Glutamate stimulates Bergmann glia to form and release d-serine, which, together with Glutamate, activates NMDA receptors on granule neurons, chemokinetically enhancing migration.

  • A direct functional link between the multi-PDZ domain Protein GRIP1 and the Fraser syndrome Protein Fras1
    Nature Genetics, 2004
    Co-Authors: Kogo Takamiya, Vassiliki Kostourou, Shalini Jadeja, Georges Chalepakis, Susanne Adams, Peter J. Scambler, Richard L Huganir, Ralf H. Adams
    Abstract:

    Cell adhesion to extracellular matrix (ECM) Proteins is crucial for the structural integrity of tissues and epithelial-mesenchymal interactions mediating organ morphogenesis^ 1 , 2 . Here we describe how the loss of a cytoplasmic multi-PDZ scaffolding Protein, Glutamate receptor interacting Protein 1 (GRIP1), leads to the formation of subepidermal hemorrhagic blisters, renal agenesis, syndactyly or polydactyly and permanent fusion of eyelids (cryptophthalmos). Similar malformations are characteristic of individuals with Fraser syndrome and animal models of this human genetic disorder, such as mice carrying the blebbed mutation ( bl ) in the gene encoding the Fras1 ECM Protein^ 3 , 4 . GRIP1 can physically interact with Fras1 and is required for the localization of Fras1 to the basal side of cells. In one animal model of Fraser syndrome, the eye-blebs ( eb ) mouse, Grip1 is disrupted by a deletion of two coding exons. Our data indicate that GRIP1 is required for normal cell-matrix interactions during early embryonic development and that inactivation of Grip1 causes Fraser syndrome–like defects in mice.

  • Glutamate receptor subunit 2 serine 880 phosphorylation modulates synaptic transmission and mediates plasticity in ca1 pyramidal cells
    The Journal of Neuroscience, 2003
    Co-Authors: Kenneth J Seidenman, Richard L Huganir, Jordan P Steinberg, Roberto Malinow
    Abstract:

    The cytoplasmic C termini of AMPA receptor subunits contain PDZ (postsynaptic density 95/Discs large/zona occludens 1) ligand domains that can control their synaptic trafficking during plasticity. The Glutamate receptor subunit 2 (GluR2) PDZ ligand domain can be phosphorylated at serine 880 (S880), and this disrupts interactions with GRIP/ABP (Glutamate Receptor-Interacting Protein/AMPA-binding Protein) but not with PICK1 (PKC-interacting Protein 1). Here, the impact of GluR2 S880 phosphorylation on synaptic transmission and plasticity was explored by expressing, in hippocampal slice cultures, GluR2 subunits containing point mutations that mimic or prevent phosphorylation at this residue. Our results indicate that mimicking GluR2 S880 phosphorylation excludes these receptors from synapses, depresses transmission, and partially occludes long-term depression (LTD). Conversely, mutations that prevent phosphorylation reduce LTD. Disruption of the interaction between GluR2 and GRIP/ABP by S880 phosphorylation may thus facilitate removal of synaptic AMPA receptors and mediate some forms of activity-dependent synaptic depression.

  • molecular mechanisms of Glutamate receptor clustering at excitatory synapses
    Current Opinion in Neurobiology, 1998
    Co-Authors: Richard Obrien, Richard L Huganir
    Abstract:

    Abstract The targeting of AMPA- and NMDA-type Glutamate receptors to synapses in the central nervous system is essential for efficient excitatory synaptic transmission. Recent studies have indicated that Protein—Protein interactions of these receptors with synaptic Proteins that contain PDZ domains are crucial for receptor targeting. NMDA receptors have been found to bind to the PSD-95 family of Proteins, whereas AMPA receptors interact with the PDZ-domain-containing Protein GRIP (Glutamate receptor interacting Protein). PSD-95 and GRIP contain multiple PDZ domains as well as other Protein—Protein interactions motifs that help to form large macromolecular complexes that may be important for the formation and plasticity of synapses.

  • grip a synaptic pdz domain containing Protein that interacts with ampa receptors
    Nature, 1997
    Co-Authors: Hualing Dong, Richard Obrien, Eric T Fung, Anthony Lanahan, Paul F Worley, Richard L Huganir
    Abstract:

    AMPA Glutamate receptors mediate the majority of rapid excitatory synaptic transmission in the central nervous system1,2 and play a role in the synaptic plasticity underlying learning and memory3,4. AMPA receptors are heteromeric complexes of four homologous subunits (GluRl–4) that differentially combine to form a variety of AMPA receptor subtypes1,2. These subunits are thought to have a large extracellular amino-terminal domain, three transmembrane domains and an intracellular carboxy-terminal domain5. AMPA receptors are localized at excitatory synapses and are not found on adjacent inhibitory synapses enriched in GABAA receptors6. The targeting of neurotransmitter receptors, such as AMPA receptors, and ion channels to synapses is essential for efficient transmission7,8. A Protein motif called a PDZ domain is important in the targeting of a variety of membrane Proteins to cell–cell junctions including synapses8–10. Here we identify a synaptic PDZ domain-containing Protein GRIP (Glutamate receptor interacting Protein) that specifically interacts with the C termini of AMPA receptors. GRIP is a new member of the PDZ domain-containing Protein family which has seven PDZ domains and no catalytic domain. GRIP appears to serve as an adapter Protein that links AMPA receptors to other Proteins and may be critical for the clustering of AMPA receptors at excitatory synapses in the brain.

Margaret A Gainey - One of the best experts on this subject based on the ideXlab platform.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

Marc Nahmani - One of the best experts on this subject based on the ideXlab platform.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

Vedakumar Tatavarty - One of the best experts on this subject based on the ideXlab platform.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.

  • activity dependent synaptic grip1 accumulation drives synaptic scaling up in response to action potential blockade
    Proceedings of the National Academy of Sciences of the United States of America, 2015
    Co-Authors: Margaret A Gainey, Marc Nahmani, Vedakumar Tatavarty, Gina G. Turrigiano
    Abstract:

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding Protein Glutamate Receptor-Interacting Protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up.