title: Identification of a small-molecule inhibitor of the PICK1 PDZ domain that inhibits hippocampal LTP and LTD.
abstract: Proteins containing PSD-95/Discs-large/ZO-1 homology (PDZ) domains play key roles in the assembly and regulation of cellular signaling pathways and represent putative targets for new pharmacotherapeutics. Here we describe the first small-molecule inhibitor (FSC231) of the PDZ domain in protein interacting with C kinase 1 (PICK1) identified by a screening of approximately 44,000 compounds in a fluorescent polarization assay. The inhibitor bound the PICK1 PDZ domain with an affinity similar to that observed for endogenous peptide ligands (K(i) approximately 10.1 microM). Mutational analysis, together with computational docking of the compound in simulations starting from the PDZ domain structure, identified the binding mode of FSC231. The specificity of FSC231 for the PICK1 PDZ domain was supported by the lack of binding to PDZ domains of postsynaptic density protein 95 (PSD-95) and glutamate receptor interacting protein 1 (GRIP1). Pretreatment of cultured hippocampal neurons with FSC231 inhibited coimmunopreciptation of the AMPA receptor GluR2 subunit with PICK1. In agreement with inhibiting the role of PICK1 in GluR2 trafficking, FSC231 accelerated recycling of pHluorin-tagged GluR2 in hippocampal neurons after internalization in response to NMDA receptor activation. FSC231 blocked the expression of both long-term depression and long-term potentiation in hippocampal CA1 neurons from acute slices, consistent with inhibition of the bidirectional function of PICK1 in synaptic plasticity. Given the proposed role of the PICK1/AMPA receptor interaction in neuropathic pain, excitotoxicity, and cocaine addiction, FSC231 might serve as a lead in the future development of new therapeutics against these conditions.
authors.affiliation: Molecular Neuropharmacology Group and Center for Pharmacogenomics, Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, DK-2200 Copenhagen, Denmark.
authors.forename: Thor S
authors.initials: TS
authors.lastname: Thorsen
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Madsen
authors.forename: Nelson
authors.initials: N
authors.lastname: Rebola
authors.forename: Mette
authors.initials: M
authors.lastname: Rathje
authors.forename: Victor
authors.initials: V
authors.lastname: Anggono
authors.forename: Anders
authors.initials: A
authors.lastname: Bach
authors.forename: Irina S
authors.initials: IS
authors.lastname: Moreira
authors.forename: Nicolai
authors.initials: N
authors.lastname: Stuhr-Hansen
authors.forename: Tino
authors.initials: T
authors.lastname: Dyhring
authors.forename: Dan
authors.initials: D
authors.lastname: Peters
authors.forename: Thijs
authors.initials: T
authors.lastname: Beuming
authors.forename: Richard
authors.initials: R
authors.lastname: Huganir
authors.forename: Harel
authors.initials: H
authors.lastname: Weinstein
authors.forename: Christophe
authors.initials: C
authors.lastname: Mulle
authors.forename: Kristian
authors.initials: K
authors.lastname: Strømgaard
authors.forename: Lars Christian B
authors.initials: LC
authors.lastname: Rønn
authors.forename: Ulrik
authors.initials: U
authors.lastname: Gether
mesh_terms: D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002219:Carbamates / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002522:Chlorocebus aethiops; D002934:Cinnamates / Q000737:chemistry / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008958:Models, Molecular; D015394:Molecular Structure; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054731:PDZ Domains; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D002219:Carbamates; D002352:Carrier Proteins; D002934:Cinnamates; D003598:Cytoskeletal Proteins; C547580:FSC 231; D009687:Nuclear Proteins; C498298:PICK1 protein, rat; D010455:Peptides; D018091:Receptors, AMPA; D011993:Recombinant Fusion Proteins; C104722:glutamate receptor ionotropic, AMPA 2