TY - JOUR
T1 - N-methyl-D-aspartate receptor-dependent regulation of the glutamate transporter excitatory amino acid carrier 1
AU - Waxman, Elisa A.
AU - Baconguis, Isabelle
AU - Lynch, David R.
AU - Robinson, Michael B.
PY - 2007/6/15
Y1 - 2007/6/15
N2 - The neuronal transporter excitatory amino acid carrier 1 (EAAC1) is enriched in perisynaptic regions, where it may regulate synaptic spillover of glutamate. In this study we examined potential interactions between EAAC1 and ionotropic glutamate receptors. N-Methyl-D-aspartate (NMDA) receptor subunits NR1, NR2A, and NR2B, but not the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunit GluR2, were co-immunoprecipitated with EAAC1 from neuron-enriched hippocampal cultures. A similar interaction was observed in C6 glioma and human embryonic kidney cells after co-transfection with Myc epitope-tagged EAAC1 and NMDA receptor subunits. Co-transfection of C6 glioma with the combination of NR1 and NR2 subunits dramatically increased (∼3-fold) the amount of Myc-EAAC1 that can be labeled with a membrane-impermeable biotinylating reagent. In hippocampal cultures, brief (5 min), robust (100 μM NMDA, 10 μM glycine) activation of the NMDA receptor decreased biotinylated EAAC1 to ∼50% of control levels. This effect was inhibited by an NMDA receptor antagonist, intracellular or extracellular calcium chelators, or hypertonic sucrose. Glutamate, α-amino-3-hydroxy-5-methyl- 4-isoxazole propionic acid with cyclothiazide, and thapsigargin mimicked the effects of NMDA. These studies suggest that NMDA receptors interact with EAAC1, facilitate cell surface expression of EAAC1 under basal conditions, and control internalization of EAAC1 upon activation. This NMDA receptor-dependent regulation of EAAC1 provides a novel mechanism that may shape excitatory signaling during synaptic plasticity and/or excitotoxicity.
AB - The neuronal transporter excitatory amino acid carrier 1 (EAAC1) is enriched in perisynaptic regions, where it may regulate synaptic spillover of glutamate. In this study we examined potential interactions between EAAC1 and ionotropic glutamate receptors. N-Methyl-D-aspartate (NMDA) receptor subunits NR1, NR2A, and NR2B, but not the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunit GluR2, were co-immunoprecipitated with EAAC1 from neuron-enriched hippocampal cultures. A similar interaction was observed in C6 glioma and human embryonic kidney cells after co-transfection with Myc epitope-tagged EAAC1 and NMDA receptor subunits. Co-transfection of C6 glioma with the combination of NR1 and NR2 subunits dramatically increased (∼3-fold) the amount of Myc-EAAC1 that can be labeled with a membrane-impermeable biotinylating reagent. In hippocampal cultures, brief (5 min), robust (100 μM NMDA, 10 μM glycine) activation of the NMDA receptor decreased biotinylated EAAC1 to ∼50% of control levels. This effect was inhibited by an NMDA receptor antagonist, intracellular or extracellular calcium chelators, or hypertonic sucrose. Glutamate, α-amino-3-hydroxy-5-methyl- 4-isoxazole propionic acid with cyclothiazide, and thapsigargin mimicked the effects of NMDA. These studies suggest that NMDA receptors interact with EAAC1, facilitate cell surface expression of EAAC1 under basal conditions, and control internalization of EAAC1 upon activation. This NMDA receptor-dependent regulation of EAAC1 provides a novel mechanism that may shape excitatory signaling during synaptic plasticity and/or excitotoxicity.
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U2 - 10.1074/jbc.M702278200
DO - 10.1074/jbc.M702278200
M3 - Article
C2 - 17459877
AN - SCOPUS:34547116203
SN - 0021-9258
VL - 282
SP - 17594
EP - 17607
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 24
ER -