Identification of a small-molecule inhibitor of the PICK1 PDZ domain that inhibits hippocampal LTP and LTD.
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.
Thorsen
Thor S
TS
Molecular Neuropharmacology Group and Center for Pharmacogenomics, Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, DK-2200 Copenhagen, Denmark.
Madsen
Kenneth L
KL
Rebola
Nelson
N
Rathje
Mette
M
Anggono
Victor
V
Bach
Anders
A
Moreira
Irina S
IS
Stuhr-Hansen
Nicolai
N
Dyhring
Tino
T
Peters
Dan
D
Beuming
Thijs
T
Huganir
Richard
R
Weinstein
Harel
H
Mulle
Christophe
C
Strømgaard
Kristian
K
Rønn
Lars Christian B
LC
Gether
Ulrik
U
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
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