The Experts below are selected from a list of 1407 Experts worldwide ranked by ideXlab platform

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

  • potent pdz domain PICK1 inhibitors that modulate amyloid beta mediated synaptic dysfunction
    Scientific Reports, 2018
    Co-Authors: Laura Silvian, Douglas Marcotte, Charles C Banos, Timothy R Chan, Robert M Arduini, Fang Qian, Darren P Baker, Chris Bergeron, Catherine Hession, Richard L Huganir
    Abstract:

    Protein interacting with C kinase (PICK1) is a scaffolding protein that is present in dendritic spines and interacts with a wide array of proteins through its PDZ domain. The best understood function of PICK1 is regulation of trafficking of AMPA receptors at neuronal synapses via its specific interaction with the AMPA GluA2 subunit. Disrupting the PICK1-GluA2 interaction has been shown to alter synaptic plasticity, a molecular mechanism of learning and memory. Lack of potent, selective inhibitors of the PICK1 PDZ domain has hindered efforts at exploring the PICK1-GluA2 interaction as a therapeutic target for neurological diseases. Here, we report the discovery of PICK1 small molecule inhibitors using a structure-based drug design strategy. The inhibitors stabilized surface GluA2, reduced Aβ-induced rise in intracellular calcium concentrations in cultured neurons, and blocked long term depression in brain slices. These findings demonstrate that it is possible to identify potent, selective PICK1-GluA2 inhibitors which may prove useful for treatment of neurodegenerative disorders.

  • synapto depressive effects of amyloid beta require PICK1
    European Journal of Neuroscience, 2014
    Co-Authors: Stephanie Alfonso, Richard L Huganir, Charles C Banos, Timothy R Chan, Kevin Guckian, Helmut W Kessels, Gnanasambandam Kumaravel, Robert H Scannevin, Kenneth J Rhodes, Anthone W Dunah
    Abstract:

    Amyloid beta (Aβ), a key component in the pathophysiology of Alzheimer's disease, is thought to target excitatory synapses early in the disease. However, the mechanism by which Aβ weakens synapses is not well understood. Here we showed that the PDZ domain protein, protein interacting with C kinase 1 (PICK1), was required for Aβ to weaken synapses. In mice lacking PICK1, elevations of Aβ failed to depress synaptic transmission in cultured brain slices. In dissociated cultured neurons, Aβ failed to reduce surface α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit 2, a subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors that binds with PICK1 through a PDZ ligand-domain interaction. Lastly, a novel small molecule (BIO922) discovered through structure-based drug design that targets the specific interactions between GluA2 and PICK1 blocked the effects of Aβ on synapses and surface receptors. We concluded that GluA2-PICK1 interactions are a key component of the effects of Aβ on synapses.

  • PICK1 loss of function occludes homeostatic synaptic scaling
    The Journal of Neuroscience, 2011
    Co-Authors: Victor Anggono, Roger L Clem, Richard L Huganir
    Abstract:

    Homeostatic synaptic scaling calibrates neuronal excitability by adjusting synaptic strengths during prolonged changes in synaptic activity. The molecular mechanisms that regulate the trafficking of AMPA receptors (AMPARs) during synaptic scaling are largely unknown. Here, we show that chronic activity blockade reduces PICK1 protein level on a time scale that coincides with the accumulation of surface AMPARs. PICK1 loss of function alters the subunit composition and the abundance of GluA2-containing AMPARs. Due to aberrant trafficking of these receptors, the increase in synaptic strength in response to synaptic inactivity is occluded in neurons generated from PICK1 knock-out mouse. In agreement with electrophysiological recordings, no defect of AMPAR trafficking is observed in PICK1 knock-out neurons in response to elevated neuronal activity. Overall, our data reveal an important role of PICK1 in inactivity-induced synaptic scaling by regulating the subunit composition, abundance, and trafficking of GluA2-containing AMPARs.

  • developmental regulation of protein interacting with c kinase 1 PICK1 function in hippocampal synaptic plasticity and learning
    Proceedings of the National Academy of Sciences of the United States of America, 2010
    Co-Authors: Lenora J Volk, Kogo Takamiya, Yilin Yu, Richard L Huganir
    Abstract:

    AMPA-type glutamate receptors (AMPARs) mediate the majority of fast excitatory neurotransmission in the mammalian central nervous system. Modulation of AMPAR trafficking supports several forms of synaptic plasticity thought to underlie learning and memory. Protein interacting with C kinase 1 (PICK1) is an AMPAR-binding protein shown to regulate both AMPAR trafficking and synaptic plasticity at many distinct synapses. However, studies examining the requirement for PICK1 in maintaining basal synaptic transmission and regulating synaptic plasticity at hippocampal Schaffer collateral–cornu ammonis 1 (SC–CA1) synapses have produced conflicting results. In addition, the effect of PICK1 manipulation on learning and memory has not been investigated. In the present study we analyzed the effect of genetic deletion of PICK1 on basal synaptic transmission and synaptic plasticity at hippocampal Schaffer collateral–CA1 synapses in adult and juvenile mice. Surprisingly, we find that loss of PICK1 has no significant effect on synaptic plasticity in juvenile mice but impairs some forms of long-term potentiation and multiple distinct forms of long-term depression in adult mice. Moreover, inhibitory avoidance learning is impaired only in adult KO mice. These results suggest that PICK1 is selectively required for hippocampal synaptic plasticity and learning in adult rodents.

  • spinal cord protein interacting with c kinase 1 is required for the maintenance of complete freund s adjuvant induced inflammatory pain but not for incision induced post operative pain
    Pain, 2010
    Co-Authors: Fidelis E Atianjoh, Kogo Takamiya, Myron Yaster, Estelle B. Gauda, Xiuli Zhao, Richard L Huganir
    Abstract:

    Abstract Protein interacting with C kinase 1 (PICK1) is a PDZ-containing protein that binds to AMPA receptor (AMPAR) GluR2 subunit and protein kinase Cα (PKCα) in the central neurons. It functions as a targeting and transport protein, presents the activated form of PKCα to synaptic GluR2, and participates in synaptic AMPAR trafficking in the nervous system. Thus, PICK1 might be involved in many physiological and pathological processes triggered via the activation of AMPARs. We report herein that PICK1 knockout mice display impaired mechanical and thermal pain hypersensitivities during complete Freund’s adjuvant (CFA)-induced inflammatory pain maintenance. Acute transient knockdown of spinal cord PICK1 through intrathecal injection of PICK1 antisense oligodeoxynucleotide had a similar effect. In contrast, knockout and knockdown of spinal cord PICK1 did not affect incision-induced guarding pain behaviors or mechanical or thermal pain hypersensitivities. We also found that PICK1 is highly expressed in dorsal horn, where it interacts with GluR2 and PKCα. Injection of CFA into a hind paw, but not a hind paw incision, increased PKCα-mediated GluR2 phosphorylation at Ser880 and GluR2 internalization in dorsal horn. These increases were absent when spinal cord PICK1 was deficient. Given that dorsal horn PKCα-mediated GluR2 phosphorylation at Ser880 and GluR2 internalization contribute to the maintenance of CFA-induced inflammatory pain, our findings suggest that spinal PICK1 may participate in the maintenance of persistent inflammatory pain, but not in incision-induced post-operative pain, through promoting PKCα-mediated GluR2 phosphorylation and internalization in dorsal horn neurons.

Graham L Collingridge - One of the best experts on this subject based on the ideXlab platform.

  • the small gtpase arf1 modulates arp2 3 mediated actin polymerization via PICK1 to regulate synaptic plasticity
    Neuron, 2013
    Co-Authors: Daniel L Rocca, Nadia Jaafari, Jack R Mellor, Mascia Amici, Anna Antoniou, Elena Blanco M Suarez, Nagaraj Halemani, Kai Murk, Jennifer Mcgarvey, Graham L Collingridge
    Abstract:

    Inhibition of Arp2/3-mediated actin polymerization by PICK1 is a central mechanism to AMPA receptor (AMPAR) internalization and long-term depression (LTD), although the signaling pathways that modulate this process in response to NMDA receptor (NMDAR) activation are unknown. Here, we define a function for the GTPase Arf1 in this process. We show that Arf1-GTP binds PICK1 to limit PICK1-mediated inhibition of Arp2/3 activity. Expression of mutant Arf1 that does not bind PICK1 leads to reduced surface levels of GluA2-containing AMPARs and smaller spines in hippocampal neurons, which occludes subsequent NMDA-induced AMPAR internalization and spine shrinkage. In organotypic slices, NMDAR-dependent LTD of AMPAR excitatory postsynaptic currents is abolished in neurons expressing mutant Arf1. Furthermore, NMDAR stimulation downregulates Arf1 activation and binding to PICK1 via the Arf-GAP GIT1. This study defines Arf1 as a critical regulator of actin dynamics and synaptic function via modulation of PICK1.

  • s17 01 metabotropic glutamate receptor mediated ltd involves two interacting ca2 sensors ncs 1 and PICK1
    European Psychiatry, 2009
    Co-Authors: Jihoon Jo, Seok Heon, Yunkyung Park, Jeremy M Henley, Jamie L Weiss, Morgan Sheng, Graham L Collingridge
    Abstract:

    There are two major forms of long-term depression (LTD) of synaptic transmission in the central nervous system, which require activation of either N-methyl-D-aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). In synapses in the perirhinal cortex we have directly compared the Ca 2+ signalling mechanisms involved in NMDAR-LTD and mGluR-LTD. Whilst both forms of LTD involve Ca 2+ release from intracellular stores the Ca 2+ sensors involved are different; NMDAR-LTD involves calmodulin, whilst mGluR-LTD involves the neuronal Ca 2+ sensor (NCS) protein NCS-1. In addition, there is a specific requirement for IP3 and PKC as well as protein interacting with C-kinase (PICK-1) in mGluR-LTD. NCS-1 binds directly to PICK1, via its BAR domain, in a Ca 2+ -dependent manner. Furthermore, the NCS-1-PICK1 association is stimulated by activation of mGluRs, but not NMDARs, and introduction of a PICK1 BAR domain fusion protein specifically blocks mGluR-LTD. Thus, NCS-1 is a component of a novel mechanism involved in mGluR-LTD.

  • metabotropic glutamate receptor mediated ltd involves two interacting ca2 sensors ncs 1 and PICK1
    Neuron, 2008
    Co-Authors: Jihoon Jo, Seok Heon, Yunkyung Park, Jeremy M Henley, Jamie L Weiss, Morgan Sheng, Graham L Collingridge
    Abstract:

    There are two major forms of long-term depression (LTD) of synaptic transmission in the central nervous system that require activation of either N-methyl-D-aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). In synapses in the perirhinal cortex, we have directly compared the Ca2+ signaling mechanisms involved in NMDAR-LTD and mGluR-LTD. While both forms of LTD involve Ca2+ release from intracellular stores, the Ca2+ sensors involved are different; NMDAR-LTD involves calmodulin, while mGluR-LTD involves the neuronal Ca2+ sensor (NCS) protein NCS-1. In addition, there is a specific requirement for IP3 and PKC, as well as protein interacting with C kinase (PICK-1) in mGluR-LTD. NCS-1 binds directly to PICK1 via its BAR domain in a Ca2+-dependent manner. Furthermore, the NCS-1-PICK1 association is stimulated by activation of mGluRs, but not NMDARs, and introduction of a PICK1 BAR domain fusion protein specifically blocks mGluR-LTD. Thus, NCS-1 plays a distinct role in mGluR-LTD.

  • an essential role for PICK1 in nmda receptor dependent bidirectional synaptic plasticity
    Neuron, 2008
    Co-Authors: Graham L Collingridge, Akira Terashima, Kenneth A Pelkey, Katherine W Roche, Chris J Mcbain, John T R Isaac
    Abstract:

    Summary PICK1 is a calcium-sensing, PDZ domain-containing protein that interacts with GluR2 and GluR3 AMPA receptor (AMPAR) subunits and regulates their trafficking. Although PICK1 has been principally implicated in long-term depression (LTD), PICK1 overexpression in CA1 pyramidal neurons causes a CaMK- and PKC-dependent potentiation of AMPAR-mediated transmission and an increase in synaptic GluR2-lacking AMPARs, mechanisms associated with NMDA receptor (NMDAR)-dependent long-term potentiation (LTP). Here, we directly tested whether PICK1 participates in both hippocampal NMDAR-dependent LTP and LTD. We show that the PICK1 potentiation of AMPAR-mediated transmission is NMDAR dependent and fully occludes LTP. Conversely, blockade of PICK1 PDZ interactions or lack of PICK1 prevents LTP. These observations demonstrate an important role for PICK1 in LTP. In addition, deletion of PICK1 or blockade of PICK1 PDZ binding prevented NMDAR-dependent LTD. Thus, PICK1 plays a critical role in bidirectional NMDAR-dependent long-term synaptic plasticity in the hippocampus.

  • regulation of synaptic strength and ampa receptor subunit composition by PICK1
    The Journal of Neuroscience, 2004
    Co-Authors: Akira Terashima, Jeremy M Henley, Graham L Collingridge, Lucy Cotton, Guido Meyer, Shahid Zaman, Fabrice Duprat, John T R Isaac
    Abstract:

    PICK1 (protein interacting with C kinase-1) regulates the surface expression of the AMPA receptor (AMPAR) GluR2 subunit, however, the functional consequences of this interaction are not well understood. Previous work has suggested that PICK1 promotes the internalization of AMPARs. However, we found that when PICK1 is virally expressed in the CA1 region of hippocampal slices, it causes an increase in AMPAR-mediated EPSC amplitude. This effect is associated with increased AMPAR rectification and sensitivity to polyamine toxin. These effects are blocked by PKC or calcium/calmodulin-dependent protein kinase II inhibitors, indicating that the virally expressed PICK1 signals through an endogenous kinase cascade. In contrast, blockade of interactions with GluR2 at the N-ethylmaleimide-sensitive factor site did not cause a change in subunit composition, suggesting that the effects of PICK1 are not simply a nonspecific consequence of removing AMPARs from the surface. Immunocytochemical and biochemical analyses in dissociated cultured hippocampal neurons show that PICK1 causes a decrease in endogenous GluR2 surface expression but no change in GluR1 surface levels. To address the physiological role of PICK1, we virally expressed C-terminal GluR2 peptides. Blockade of endogenous PICK1 PDZ (postsynaptic density-95/Discs large/zona occludens-1) domain interactions produced opposite effects on synaptic strength and AMPAR rectification to those observed with PICK1 expression. This demonstrates that AMPAR subunit composition is physiologically regulated through a mechanism involving PICK1 PDZ domain interactions. These findings suggest that PICK1 acts to downregulate the GluR2 content of AMPARs at hippocampal CA1 synapses, thereby increasing synaptic strength at resting membrane potentials.

Jeremy M Henley - One of the best experts on this subject based on the ideXlab platform.

  • PICK1 inhibition of the arp2 3 complex controls dendritic spine size and synaptic plasticity
    The EMBO Journal, 2011
    Co-Authors: Yasuko Nakamura, Jeremy M Henley, Catherine L Wood, Andrew P Patton, Nadia Jaafari, Jack R Mellor, Jonathan G Hanley
    Abstract:

    Activity-dependent remodelling of dendritic spines is essential for neural circuit development and synaptic plasticity, but the precise molecular mechanisms that regulate this process are unclear. Activators of Arp2/3-mediated actin polymerisation are required for spine enlargement; however, during long-term depression (LTD), spines shrink via actin depolymerisation and Arp2/3 inhibitors in this process have not yet been identified. Here, we show that PICK1 regulates spine size in hippocampal neurons via inhibition of the Arp2/3 complex. PICK1 knockdown increases spine size, whereas PICK1 overexpression reduces spine size. NMDA receptor activation results in spine shrinkage, which is blocked by PICK1 knockdown or overexpression of a PICK1 mutant that cannot bind Arp2/3. Furthermore, we show that PICK1–Arp2/3 interactions are required for functional hippocampal LTD. This work demonstrates that PICK1 is a novel regulator of spine dynamics. Via Arp2/3 inhibition, PICK1 has complementary yet distinct roles during LTD to regulate AMPA receptor trafficking and spine size, and therefore functions as a crucial factor in both structural and functional plasticity.

  • PICK1 inhibition of the Arp2/3 complex controls dendritic spine size and synaptic plasticity
    The EMBO Journal, 2011
    Co-Authors: Yasuko Nakamura, Jeremy M Henley, Catherine L Wood, Andrew P Patton, Nadia Jaafari, Jack R Mellor, Jonathan G Hanley
    Abstract:

    Activity-dependent remodelling of dendritic spines is essential for neural circuit development and synaptic plasticity, but the precise molecular mechanisms that regulate this process are unclear. Activators of Arp2/3-mediated actin polymerisation are required for spine enlargement; however, during long-term depression (LTD), spines shrink via actin depolymerisation and Arp2/3 inhibitors in this process have not yet been identified. Here, we show that PICK1 regulates spine size in hippocampal neurons via inhibition of the Arp2/3 complex. PICK1 knockdown increases spine size, whereas PICK1 overexpression reduces spine size. NMDA receptor activation results in spine shrinkage, which is blocked by PICK1 knockdown or overexpression of a PICK1 mutant that cannot bind Arp2/3. Furthermore, we show that PICK1–Arp2/3 interactions are required for functional hippocampal LTD. This work demonstrates that PICK1 is a novel regulator of spine dynamics. Via Arp2/3 inhibition, PICK1 has complementary yet distinct roles during LTD to regulate AMPA receptor trafficking and spine size, and therefore functions as a crucial factor in both structural and functional plasticity.

  • s17 01 metabotropic glutamate receptor mediated ltd involves two interacting ca2 sensors ncs 1 and PICK1
    European Psychiatry, 2009
    Co-Authors: Jihoon Jo, Seok Heon, Yunkyung Park, Jeremy M Henley, Jamie L Weiss, Morgan Sheng, Graham L Collingridge
    Abstract:

    There are two major forms of long-term depression (LTD) of synaptic transmission in the central nervous system, which require activation of either N-methyl-D-aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). In synapses in the perirhinal cortex we have directly compared the Ca 2+ signalling mechanisms involved in NMDAR-LTD and mGluR-LTD. Whilst both forms of LTD involve Ca 2+ release from intracellular stores the Ca 2+ sensors involved are different; NMDAR-LTD involves calmodulin, whilst mGluR-LTD involves the neuronal Ca 2+ sensor (NCS) protein NCS-1. In addition, there is a specific requirement for IP3 and PKC as well as protein interacting with C-kinase (PICK-1) in mGluR-LTD. NCS-1 binds directly to PICK1, via its BAR domain, in a Ca 2+ -dependent manner. Furthermore, the NCS-1-PICK1 association is stimulated by activation of mGluRs, but not NMDARs, and introduction of a PICK1 BAR domain fusion protein specifically blocks mGluR-LTD. Thus, NCS-1 is a component of a novel mechanism involved in mGluR-LTD.

  • metabotropic glutamate receptor mediated ltd involves two interacting ca2 sensors ncs 1 and PICK1
    Neuron, 2008
    Co-Authors: Jihoon Jo, Seok Heon, Yunkyung Park, Jeremy M Henley, Jamie L Weiss, Morgan Sheng, Graham L Collingridge
    Abstract:

    There are two major forms of long-term depression (LTD) of synaptic transmission in the central nervous system that require activation of either N-methyl-D-aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). In synapses in the perirhinal cortex, we have directly compared the Ca2+ signaling mechanisms involved in NMDAR-LTD and mGluR-LTD. While both forms of LTD involve Ca2+ release from intracellular stores, the Ca2+ sensors involved are different; NMDAR-LTD involves calmodulin, while mGluR-LTD involves the neuronal Ca2+ sensor (NCS) protein NCS-1. In addition, there is a specific requirement for IP3 and PKC, as well as protein interacting with C kinase (PICK-1) in mGluR-LTD. NCS-1 binds directly to PICK1 via its BAR domain in a Ca2+-dependent manner. Furthermore, the NCS-1-PICK1 association is stimulated by activation of mGluRs, but not NMDARs, and introduction of a PICK1 BAR domain fusion protein specifically blocks mGluR-LTD. Thus, NCS-1 plays a distinct role in mGluR-LTD.

  • the pdz domain of PICK1 differentially accepts protein kinase c α and glur2 as interacting ligands
    Journal of Biological Chemistry, 2004
    Co-Authors: Shigetada Nakanishi, Jeremy M Henley
    Abstract:

    Abstract The C terminus (ct) of protein kinase C-α (PKCα) has a type I PDZ binding motif, whereas GluR2 has a type II PDZ binding motif. Both motifs are recognized by the PDZ domain of protein interacting with protein kinase C (PICK1), and PICK1-PKCα-controlled phosphorylation regulates the synaptic expression and function of GluR2. Here, we show that a specific mutation within the carboxylate-binding loop of the PDZ domain of PICK1 (K27E; PICK1-KE) results in a loss of interaction with GluR2 but not with PKCα. In GST pull-down studies, PICK1-WT (wild type) but not PICK1-KE was retained by GST-ct-GluR2. Furthermore, PICK1-WT co-immunoprecipitated both PKCα and GluR2, whereas PICK1-KE only co-immunoprecipitated PKCα. In heterologous cells, PICK1-WT, but not PICK1-KE, clustered GluR2 and also clustered GluR1 in a GluR2-dependent manner. However, neither PICK1-WT nor PICK1-KE altered the distribution of PKCα, even after phorbol ester-induced redistribution of PKCα to the membrane. Finally, PICK1-KE showed no mislocalization when compared with PICK1-WT in neurons. Taken together, it appears that the PDZ domain of PICK1 is less sensitive to mutations for PKCα when compared with GluR2 binding. These results suggest that the PDZ domain of PICK1 has distinct PKCα and GluR2 binding subsite(s).

Jonathan G Hanley - One of the best experts on this subject based on the ideXlab platform.

  • the PICK1 ca2 sensor modulates n methyl d aspartate nmda receptor dependent microrna mediated translational repression in neurons
    Journal of Biological Chemistry, 2017
    Co-Authors: Dipen Rajgor, Maria Fiuza, Gabrielle T Parkinson, Jonathan G Hanley
    Abstract:

    Abstract MicroRNAs (miRNAs) are important regulators of localized mRNA translation in neuronal dendrites. The presence of RNA-induced silencing complex proteins in these compartments and the dynamic miRNA expression changes that occur in response to neuronal stimulation highlight their importance in synaptic plasticity. Previously, we demonstrated a novel interaction between the major RNA-induced silencing complex component Argounaute-2 (Ago2) and the BAR (bin/amphiphysin/rvs) domain protein PICK1. PICK1 recruits Ago2 to recycling endosomes in dendrites, where it inhibits miRNA-mediated translational repression. Chemical induction of long-term depression via NMDA receptor activation causes the dissociation of Ago2 from PICK1 and a consequent increase in dendritic miRNA-mediated gene silencing. The mechanism that underlies the regulation of PICK1-Ago2 binding is unknown. In this study, we demonstrate that the PICK1-Ago2 interaction is directly sensitive to Ca2+ ions so that high [Ca2+]free reduces PICK1 binding to Ago2. Mutating a stretch of C-terminal Ca2+-binding residues in PICK1 results in a complete block of NMDA-induced PICK1-Ago2 disassociation in cortical neurons. Furthermore, the same mutant also blocks NMDA-stimulated miRNA-mediated gene silencing. This study defines a novel mechanism whereby elevated [Ca2+] induced by NMDA receptor activation modulates Ago2 and miRNA activity via PICK1. Our work suggests a Ca2+-dependent process to regulate miRNA activity in neurons in response to the induction of long-term depression.

  • PICK1 inhibition of the arp2 3 complex controls dendritic spine size and synaptic plasticity
    The EMBO Journal, 2011
    Co-Authors: Yasuko Nakamura, Jeremy M Henley, Catherine L Wood, Andrew P Patton, Nadia Jaafari, Jack R Mellor, Jonathan G Hanley
    Abstract:

    Activity-dependent remodelling of dendritic spines is essential for neural circuit development and synaptic plasticity, but the precise molecular mechanisms that regulate this process are unclear. Activators of Arp2/3-mediated actin polymerisation are required for spine enlargement; however, during long-term depression (LTD), spines shrink via actin depolymerisation and Arp2/3 inhibitors in this process have not yet been identified. Here, we show that PICK1 regulates spine size in hippocampal neurons via inhibition of the Arp2/3 complex. PICK1 knockdown increases spine size, whereas PICK1 overexpression reduces spine size. NMDA receptor activation results in spine shrinkage, which is blocked by PICK1 knockdown or overexpression of a PICK1 mutant that cannot bind Arp2/3. Furthermore, we show that PICK1–Arp2/3 interactions are required for functional hippocampal LTD. This work demonstrates that PICK1 is a novel regulator of spine dynamics. Via Arp2/3 inhibition, PICK1 has complementary yet distinct roles during LTD to regulate AMPA receptor trafficking and spine size, and therefore functions as a crucial factor in both structural and functional plasticity.

  • PICK1 inhibition of the Arp2/3 complex controls dendritic spine size and synaptic plasticity
    The EMBO Journal, 2011
    Co-Authors: Yasuko Nakamura, Jeremy M Henley, Catherine L Wood, Andrew P Patton, Nadia Jaafari, Jack R Mellor, Jonathan G Hanley
    Abstract:

    Activity-dependent remodelling of dendritic spines is essential for neural circuit development and synaptic plasticity, but the precise molecular mechanisms that regulate this process are unclear. Activators of Arp2/3-mediated actin polymerisation are required for spine enlargement; however, during long-term depression (LTD), spines shrink via actin depolymerisation and Arp2/3 inhibitors in this process have not yet been identified. Here, we show that PICK1 regulates spine size in hippocampal neurons via inhibition of the Arp2/3 complex. PICK1 knockdown increases spine size, whereas PICK1 overexpression reduces spine size. NMDA receptor activation results in spine shrinkage, which is blocked by PICK1 knockdown or overexpression of a PICK1 mutant that cannot bind Arp2/3. Furthermore, we show that PICK1–Arp2/3 interactions are required for functional hippocampal LTD. This work demonstrates that PICK1 is a novel regulator of spine dynamics. Via Arp2/3 inhibition, PICK1 has complementary yet distinct roles during LTD to regulate AMPA receptor trafficking and spine size, and therefore functions as a crucial factor in both structural and functional plasticity.

  • molecular mechanisms for regulation of ampar trafficking by PICK1
    Biochemical Society Transactions, 2006
    Co-Authors: Jonathan G Hanley
    Abstract:

    AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) receptor trafficking is a fundamental mechanism for regulating synaptic strength, and hence may underlie cellular processes involved in learning and memory. PICK1 ( p rotein that i nteracts with protein C - k inase) has recently emerged as a key regulator of AMPAR (AMPA receptor) traffic, and the precise molecular mechanisms of PICK1's action are just beginning to be unravelled. In this review, I summarize recent findings that describe some important molecular characteristics of PICK1 with respect to AMPAR cell biology. Abbreviations: AMPA, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid; AMPAR, AMPA receptor; ABP, AMPAR-binding protein; BAR, Bin/amphiphysin/Rvs; LTD, long-term depression; GRIP, glutamate receptor-interacting protein; LTP, long-term potentiation; NMDA, N-methyl-D-aspartate; NMDAR, NMDA receptor; NSF, N-ethylmaleimide-sensitive fusion; PICK, protein that interacts with C-kinase; PKC, protein kinase C; SNAP, soluble NSF protein-attachment protein; SNARE, SNAP receptor

  • nsf atpase and α β snaps disassemble the ampa receptor PICK1 complex
    Neuron, 2002
    Co-Authors: Jonathan G Hanley, Latika Khatri, Phyllis I Hanson, Edward B Ziff
    Abstract:

    Abstract AMPA receptor (AMPAR) trafficking is crucial for synaptic plasticity that may be important for learning and memory. NSF and PICK1 bind the AMPAR GluR2 subunit and are involved in trafficking of AMPARs. Here, we show that GluR2, PICK1, NSF, and α-/β-SNAPs form a complex in the presence of ATPγS. Similar to SNARE complex disassembly, NSF ATPase activity disrupts PICK1-GluR2 interactions in this complex. α- and β-SNAP have differential effects on this reaction. SNAP overexpression in hippocampal neurons leads to corresponding changes in AMPAR trafficking by acting on GluR2-PICK1 complexes. This demonstrates that the previously reported synaptic stabilization of AMPARs by NSF involves disruption of GluR2-PICK1 interactions. Furthermore, we are reporting a non-SNARE substrate for NSF disassembly activity.

Kenneth L. Madsen - One of the best experts on this subject based on the ideXlab platform.

  • administration of a novel high affinity PICK1 pdz domain inhibitor attenuates cocaine seeking in rats
    Neuropharmacology, 2020
    Co-Authors: Christopher A Turner, Kenneth L. Madsen, Marta De Luca, Jordan Wolfheimer, Nicole S Hernandez, Heath D Schmidt
    Abstract:

    Abstract Protein interacting with C kinase-1 (PICK1) regulates intra-cellular trafficking of GluA2-containing AMPA receptors, a process known to play a critical role in cocaine-seeking behavior. This suggests that PICK1 may represent a molecular target for developing novel pharmacotherapies to treat cocaine craving-induced relapse. Emerging evidence indicates that inhibition of PICK1 attenuates the reinstatement of cocaine-seeking behavior, an animal model of relapse. Here, we show that systemic administration of TAT-P4-(DATC5)2, a novel high-affinity peptide inhibitor of the PICK1 PDZ domain, dose-dependently attenuated the reinstatement of cocaine seeking in rats at doses that did not produce operant learning deficits or suppress locomotor activity. We also show that systemic TAT-P4-(DATC5)2 penetrated the brain where it was visualized in the nucleus accumbens shell. Consistent with these effects, infusions of TAT-P4-(DATC5)2 directly into the accumbens shell reduced cocaine, but not sucrose, seeking. The effects of TAT-P4-(DATC5)2 on cocaine seeking are likely due, in part, to inhibition of PICK1 in medium spiny neurons (MSNs) of the accumbens shell as TAT-P4-(DATC5)2 was shown to accumulate in striatal neurons and bind PICK1. Taken together, these findings highlight a novel role for PICK1 in the reinstatement of cocaine seeking and support future studies examining the efficacy of peptide inhibitors of PICK1 in animal and human models of cocaine relapse.

  • the bar domain protein PICK1 controls vesicle number and size in adrenal chromaffin cells
    The Journal of Neuroscience, 2014
    Co-Authors: Paulo S Pinheiro, Kenneth L. Madsen, Ulrik Gether, Anna M Jansen, Bassam Tawfik, Matthijs Verhage, Jakob B Sorensen
    Abstract:

    Protein Interacting with C Kinase 1 (PICK1) is a Bin/Amphiphysin/Rvs (BAR) domain protein involved in AMPA receptor trafficking. Here, we identify a selective role for PICK1 in the biogenesis of large, dense core vesicles (LDCVs) in mouse chromaffin cells. PICK1 colocalized with syntaxin-6, a marker for immature granules. In chromaffin cells isolated from a PICK1 knockout (KO) mouse the amount of exocytosis was reduced, while release kinetics and Ca2+ sensitivity were unaffected. Vesicle-fusion events had a reduced frequency and released lower amounts of transmitter per vesicle (i.e., reduced quantal size). This was paralleled by a reduction in the mean single-vesicle capacitance, estimated by averaging time-locked capacitance traces. EM confirmed that LDCVs were fewer and of markedly reduced size in the PICK1 KO, demonstrating that all phenotypes can be explained by reductions in vesicle number and size, whereas the fusion competence of generated vesicles was unaffected by the absence of PICK1. Viral rescue experiments demonstrated that long-term re-expression of PICK1 is necessary to restore normal vesicular content and secretion, while short-term overexpression is ineffective, consistent with an upstream role for PICK1. Disrupting lipid binding of the BAR domain (2K-E mutation) or of the PDZ domain (CC-GG mutation) was sufficient to reproduce the secretion phenotype of the null mutant. The same mutations are known to eliminate PICK1 function in receptor trafficking, indicating that the multiple functions of PICK1 involve a conserved mechanism. Summarized, our findings demonstrate that PICK1 functions in vesicle biogenesis and is necessary to maintain normal vesicle numbers and size.

  • PICK1 deficiency impairs secretory vesicle biogenesis and leads to growth retardation and decreased glucose tolerance
    PLOS Biology, 2013
    Co-Authors: Birgitte Holst, Kenneth L. Madsen, Anna M Jansen, Gunnar Sorensen, Mattias Rickhag, Viktor K Lund, Morten Jensen, Vikram K Bhatia, Andreas N Madsen, Siri K Moller
    Abstract:

    Secretory vesicles in endocrine cells store hormones such as growth hormone (GH) and insulin before their release into the bloodstream. The molecular mechanisms governing budding of immature secretory vesicles from the trans-Golgi network (TGN) and their subsequent maturation remain unclear. Here, we identify the lipid binding BAR (Bin/amphiphysin/Rvs) domain protein PICK1 (protein interacting with C kinase 1) as a key component early in the biogenesis of secretory vesicles in GH-producing cells. Both PICK1-deficient Drosophila and mice displayed somatic growth retardation. Growth retardation was rescued in flies by reintroducing PICK1 in neurosecretory cells producing somatotropic peptides. PICK1-deficient mice were characterized by decreased body weight and length, increased fat accumulation, impaired GH secretion, and decreased storage of GH in the pituitary. Decreased GH storage was supported by electron microscopy showing prominent reduction in secretory vesicle number. Evidence was also obtained for impaired insulin secretion associated with decreased glucose tolerance. PICK1 localized in cells to immature secretory vesicles, and the PICK1 BAR domain was shown by live imaging to associate with vesicles budding from the TGN and to possess membrane-sculpting properties in vitro. In mouse pituitary, PICK1 co-localized with the BAR domain protein ICA69, and PICK1 deficiency abolished ICA69 protein expression. In the Drosophila brain, PICK1 and ICA69 co-immunoprecipitated and showed mutually dependent expression. Finally, both in a Drosophila model of type 2 diabetes and in high-fat-diet-induced obese mice, we observed up-regulation of PICK1 mRNA expression. Our findings suggest that PICK1, together with ICA69, is critical during budding of immature secretory vesicles from the TGN and thus for vesicular storage of GH and possibly other hormones. The data link two BAR domain proteins to membrane remodeling processes in the secretory pathway of peptidergic endocrine cells and support an important role of PICK1/ICA69 in maintenance of metabolic homeostasis.

  • serine 77 in the pdz domain of PICK1 is a protein kinase cα phosphorylation site regulated by lipid membrane binding
    Biochemistry, 2012
    Co-Authors: Ina Ammendrupjohnsen, Thor S. Thorsen, Ulrik Gether, Kenneth L. Madsen
    Abstract:

    : PICK1 (protein interacting with C kinase 1) contains an N-terminal protein binding PDZ domain and a C-terminal lipid binding BAR domain. PICK1 plays a key role in several physiological processes, including synaptic plasticity. However, little is known about the cellular mechanisms governing the activity of PICK1 itself. Here we show that PICK1 is a substrate in vitro both for PKCα (protein kinase Cα), as previously shown, and for CaMKIIα (Ca(2+)-calmodulin-dependent protein kinase IIα). By mutation of predicted phosphorylation sites, we identify Ser77 in the PDZ domain as a major phosphorylation site for PKCα. Mutation of Ser77 reduced the level of PKCα-mediated phosphorylation ~50%, whereas no reduction was observed upon mutation of seven other predicted sites. Addition of lipid vesicles increased the level of phosphorylation of Ser77 10-fold, indicating that lipid binding is critical for optimal phosphorylation. Binding of PKCα to the PICK1 PDZ domain was not required for phosphorylation, but a PDZ domain peptide ligand reduced the overall level of phosphorylation ~30%. The phosphomimic S77D reduced the extent of cytosolic clustering of eYFP-PICK1 in COS7 cells and thereby conceivably its lipid binding and/or polymerization capacity. We propose that PICK1 is phosphorylated at Ser77 by PKCα preferentially when bound to membrane vesicles and that this phosphorylation in turn modulates its cellular distribution.

  • Protein interacting with C kinase 1 (PICK1) reduces reinsertion rates of interaction partners sorted to Rab11-dependent slow recycling pathway
    Journal of Biological Chemistry, 2012
    Co-Authors: Kenneth L. Madsen, Troels Rahbek-clemmensen, Jacob Eriksen, Thor S. Thorsen, Ulrik Gether
    Abstract:

    The scaffolding protein PICK1 (protein interacting with C kinase 1) contains an N-terminal PSD-95/Discs large/ZO-1 (PDZ) domain and a central lipid-binding Bin/amphiphysin/Rvs (BAR) domain. PICK1 is thought to regulate trafficking of its PDZ binding partners but different and even opposing functions have been suggested. Here, we apply ELISA-based assays and confocal microscopy in HEK293 cells with inducible PICK1 expression to assess in an isolated system the ability of PICK1 to regulate trafficking of natural and engineered PDZ binding partners. The dopamine transporter (DAT), which primarily sorts to degradation upon internalization, did not form perinuclear clusters with PICK1, and PICK1 did not affect DAT internalization/recycling. However, transfer of the PICK1-binding DAT C terminus to the β(2)-adrenergic receptor, which sorts to recycling upon internalization, led to formation of PICK1 co-clusters in Rab11-positive compartments. Furthermore, PICK1 inhibited Rab11-mediated recycling of the receptor in a BAR and PDZ domain-dependent manner. In contrast, transfer of the DAT C terminus to the δ-opioid receptor, which sorts to degradation, did not result in PICK1 co-clusters or any change in internalization/recycling. Further support for a role of PICK1 determined by its PDZ cargo was obtained for the PICK1 interaction partner prolactin-releasing peptide receptor (GPR10). GPR10 co-localized with Rab11 and clustered with PICK1 upon constitutive internalization but co-localized with the late endosomal marker Rab7 and did not cluster with PICK1 upon agonist-induced internalization. Our data suggest a selective role of PICK1 in clustering and reducing the recycling rates of PDZ domain binding partners sorted to the Rab11-dependent recycling pathway.