TY - JOUR
T1 - Interaction of the N-methyl-D-aspartate receptor complex with a novel synapse-associated protein, SAP102
AU - Lau, Lit Fui
AU - Mammen, Andrew
AU - Enters, Michael D.
AU - Kindler, Stefan
AU - Chung, Wook Joon
AU - Garner, Craig C.
AU - Huganirt, Richard L.
PY - 1996
Y1 - 1996
N2 - Ionotropic glutamate receptors are known to cluster at high concentration on the postsynaptic membrane of excitatory synapses, but the mechanism by which this occurs is poorly understood. Studies on the neuromuscular junction and central inhibitory synapses suggest that clustering of neurotransmitter receptors requires its interaction with a cytoplasmic protein. Recently, in vitro studies have shown that members of the N-methylo-aspartate (NMDA) class of glutamate receptors interact with a synapse-associated protein, SAP90 (PSD-95). However, evidence for the in vivo interaction of MDA receptors with SAPs is still lacking. In the present study, we demonstrate the specific interaction between SAP102, a novel synapse-associated protein, and the NMDA receptor complex from the rat cortical synaptic plasma membranes using co-immunoprecipitation techniques. No association was observed between SAP102 and GluR1, a member of the α- amino-3-hydroxy-5-methyl-4-isoxazolepropionate class of glutamate receptors. To identify the domain on the NMDA receptor responsible for this interaction, we constructed hexahistidine fusion proteins from different regions of the NRla and NR2 subunits of the NMDA receptor. Immunoblot overlay experiments showed that while the C-terminal domain of the NR2 subunit displayed strong binding, the NRla intracellular C-terminal tail did not interact with SAP102. The site of interaction was more precisely located to the last 20 amino acids of the NR2 subunit as indicated by the interaction of the synthetic peptide with SAP102. In summary, we demonstrate here for the first time an in vivo interaction between the native NMDA receptor complex and a synapse-associated protein. These results suggest that SAP102 may play an important role in NMDA receptor clustering and immobilization at excitatory synapses.
AB - Ionotropic glutamate receptors are known to cluster at high concentration on the postsynaptic membrane of excitatory synapses, but the mechanism by which this occurs is poorly understood. Studies on the neuromuscular junction and central inhibitory synapses suggest that clustering of neurotransmitter receptors requires its interaction with a cytoplasmic protein. Recently, in vitro studies have shown that members of the N-methylo-aspartate (NMDA) class of glutamate receptors interact with a synapse-associated protein, SAP90 (PSD-95). However, evidence for the in vivo interaction of MDA receptors with SAPs is still lacking. In the present study, we demonstrate the specific interaction between SAP102, a novel synapse-associated protein, and the NMDA receptor complex from the rat cortical synaptic plasma membranes using co-immunoprecipitation techniques. No association was observed between SAP102 and GluR1, a member of the α- amino-3-hydroxy-5-methyl-4-isoxazolepropionate class of glutamate receptors. To identify the domain on the NMDA receptor responsible for this interaction, we constructed hexahistidine fusion proteins from different regions of the NRla and NR2 subunits of the NMDA receptor. Immunoblot overlay experiments showed that while the C-terminal domain of the NR2 subunit displayed strong binding, the NRla intracellular C-terminal tail did not interact with SAP102. The site of interaction was more precisely located to the last 20 amino acids of the NR2 subunit as indicated by the interaction of the synthetic peptide with SAP102. In summary, we demonstrate here for the first time an in vivo interaction between the native NMDA receptor complex and a synapse-associated protein. These results suggest that SAP102 may play an important role in NMDA receptor clustering and immobilization at excitatory synapses.
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U2 - 10.1074/jbc.271.35.21622
DO - 10.1074/jbc.271.35.21622
M3 - Article
C2 - 8702950
AN - SCOPUS:0029788216
SN - 0021-9258
VL - 271
SP - 21622
EP - 21628
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 35
ER -