重组NMDA受体通道的钙依赖性瞬时失活不涉及NR1亚基的高亲和力钙调蛋白结合位点。

The calcium-dependent transient inactivation of recombinant NMDA receptor-channel does not involve the high affinity calmodulin binding site of the NR1 subunit.

作者信息

Rafiki A, Gozlan H, Ben-Ari Y, Khrestchatisky M, Medina I

机构信息

INSERM U29, 123, Paris, France.

出版信息

Neurosci Lett. 1997 Feb 21;223(2):137-9. doi: 10.1016/s0304-3940(97)13413-9.

DOI:10.1016/s0304-3940(97)13413-9

PMID:9089692

Abstract

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.

摘要

N-甲基-D-天冬氨酸（NMDA）受体功能可通过钙调蛋白直接结合到NR1亚基C末端区域的低亲和力和高亲和力（C1外显子盒）位点来调节。为了评估高亲和力结合位点在细胞内钙引起的NMDA受体通道瞬时失活中的作用，已将NR1亚基的几种剪接变体分别与NR2A亚基共转染到HEK 293细胞中。无论NR1变体含有（NR1-1a、1b）还是缺乏（NR1-2a、2b、4a、4b）带有钙调蛋白高亲和力结合位点的C1外显子盒，异聚体受体的瞬时Ca2+诱导失活（40-50%）都是相似的。这表明该位点不参与NMDA受体的Ca2+依赖性瞬时失活。