The calcium-dependent transient inactivation of recombinant NMDA receptor-channel does not involve the high affinity calmodulin binding site of the NR1 subunit.
N-methyl-D-aspartate (NMDA) receptor function can be regulated by direct binding of calmodulin to a low and high affinity (C1 exon cassette) site in the C-terminal region of the NR1 subunit. To evaluate the involvement of the high affinity binding site in the transient inactivation of the NMDA receptor-channels by intracellular calcium, several splice variants of the NR1 subunit have been individually co-transfected with the NR2A subunit in HEK 293 cells. The transient Ca2+ induced inactivation (40-50%) of the heteromeric receptors was similar whether the NR1 variants contained (NR1-1a, 1b) or lacked (NR1-2a, 2b, 4a, 4b) the C1 exon cassette bearing the high affinity binding site for calmodulin. This demonstrates that this site is not involved in the Ca2+ dependent transient inactivation of NMDA receptors.
Rafiki
A
A
INSERM U29, 123, Paris, France.
Gozlan
H
H
Ben-Ari
Y
Y
Khrestchatisky
M
M
Medina
I
I
D001667:Binding, Competitive; D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000378:metabolism*; D002461:Cell Line, Transformed; D006801:Humans; D007473:Ion Channels / Q000037:antagonists & inhibitors*; D018408:Patch-Clamp Techniques; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D011994:Recombinant Proteins; D013997:Time Factors
D002147:Calmodulin; D007473:Ion Channels; D016194:Receptors, N-Methyl-D-Aspartate; D011994:Recombinant Proteins; D002118:Calcium