title: Interaction of the synaptic protein PICK1 (protein interacting with C kinase 1) with the non-voltage gated sodium channels BNC1 (brain Na+ channel 1) and ASIC (acid-sensing ion channel).
abstract: Neuronal members of the degenerin/epithelial Na(+) channel (DEG/ENaC) family of cation channels include the mammalian brain Na(+) channel 1 (BNC1), acid-sensing ion channel (ASIC) and dorsal-root acid-sensing ion channel (DRASIC). Their response to acidic pH, their sequence similarity to nematode proteins involved in mechanotransduction and their modulation by neuropeptides suggest that they may function as receptors for a number of different stimuli. Using the yeast two-hybrid assay, we found that the PDZ domain-containing protein PICK1 (protein interacting with C kinase) interacts specifically with the C-termini of BNC1 and ASIC, but not DRASIC or the related alphaENaC or betaENaC. In both the yeast two-hybrid system and mammalian cells, deletion of the BNC1 and ASIC C-termini abolished the interaction with PICK1. Likewise, mutating the PDZ domain in PICK1 abolished its interaction with BNC1 and ASIC. In addition, in a heterologous expression system PICK1 altered the distribution of BNC1 channels; this effect was dependent on the PDZ domain of PICK1 and the C-terminus of BNC1. We found crude synaptosomal fractions of brain to be enriched in ASIC, suggesting a possible synaptic localization. Moreover, in transfected hippocampal neurons ASIC co-localized with PICK1 in a punctate pattern at synapses. These data suggest that PICK1 binds ASIC and BNC1 via its PDZ domain. This interaction may be important for the localization and/or function of these channels in both the central and peripheral nervous systems.
authors.affiliation: Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City, IA 52242, U.S.A.
authors.forename: Alesia M
authors.initials: AM
authors.lastname: Hruska-Hageman
authors.forename: John A
authors.initials: JA
authors.lastname: Wemmie
authors.forename: Margaret P
authors.initials: MP
authors.lastname: Price
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Welsh
mesh_terms: D062565:Acid Sensing Ion Channels; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D003598:Cytoskeletal Proteins; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels; D006624:Hippocampus / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D015222:Sodium Channels / Q000737:chemistry / Q000378:metabolism*; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: C568424:ASIC2 protein, human; C112231:ASIC3 protein, human; C568269:ASIC3 protein, rat; D062565:Acid Sensing Ion Channels; C568425:Asic2 protein, rat; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels; D007473:Ion Channels; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C498298:PICK1 protein, rat; D015222:Sodium Channels; D003094:Collagen; D004247:DNA