Soloviev M M, Brierley M J, Shao Z Y, Mellor I R, Volkova T M, Kamboj R, Ishimaru H, Sudan H, Harris J, Foldes R L, Grishin E V, Usherwood P N, Barnard E A
Molecular Neurobiology Unit, Royal Free Hospital School of Medicine, London NW3 2PF, United Kingdom.
J Biol Chem. 1996 Dec 20;271(51):32572-9. doi: 10.1074/jbc.271.51.32572.
A cDNA encoding a 100-kDa subunit (XenNR1) of the N-methyl-D-aspartate (NMDA) glutamate receptor type has been cloned from Xenopus central nervous system. When XenNR1 is coexpressed in a mammalian cell line with a recently cloned 51-kDa non-NMDA receptor subunit (XenU1), also from Xenopus, it forms a functional unitary receptor exhibiting the pharmacological properties characteristic of both NMDA and non-NMDA receptors. Firstly, XenU1 can replace NR2 subunits, in complementing XenNR1 to introduce the ligand binding properties of a complete NMDA receptor. Second, responses to both NMDA and non-NMDA receptor agonists and antagonists were obtained in patch-clamp recordings from the cotransfected cells, but no significant responses were recorded when the cells were singly transfected. Third, from solubilized cell membranes from the cotransfected cells, an antibody to the NR1 subunit coprecipitated the binding sites of the non-NMDA receptor subunit. The unitary glutamate receptor has a unique set of properties that denote intersubunit interaction, including a glycine requirement for the responses to non-NMDA as well as to NMDA receptor agonists and voltage-dependent block by Mg2+ of the non-NMDA agonist responses.
已从非洲爪蟾的中枢神经系统克隆出一种编码 N-甲基-D-天冬氨酸（NMDA）型谷氨酸受体 100 kDa 亚基（XenNR1）的互补 DNA。当 XenNR1 与同样来自非洲爪蟾且最近克隆出的 51 kDa 非 NMDA 受体亚基（XenU1）在哺乳动物细胞系中共表达时，它形成了一个功能性单一受体，展现出 NMDA 和非 NMDA 受体的药理学特性。首先，在补充 XenNR1 以引入完整 NMDA 受体的配体结合特性方面，XenU1 可以替代 NR2 亚基。其次，从共转染细胞的膜片钳记录中获得了对 NMDA 和非 NMDA 受体激动剂及拮抗剂的反应，但对单独转染的细胞进行记录时未观察到明显反应。第三，从共转染细胞的溶解细胞膜中，针对 NR1 亚基的抗体共沉淀出非 NMDA 受体亚基的结合位点。单一谷氨酸受体具有一组独特的特性，表明亚基间存在相互作用，包括对非 NMDA 以及 NMDA 受体激动剂反应所需的甘氨酸，以及 Mg2 +对非 NMDA 激动剂反应的电压依赖性阻断。
