Pentameric subunit stoichiometry of a neuronal glutamate receptor
Pentameric subunit stoichiometry of a neuronal glutamate receptor
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DOI：
10.1073/pnas.93.7.2741
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发表时间：
1996-04-02
影响因子：
11.1
通讯作者：
Montal, M
中科院分区：
文献类型：
--
作者：
FerrerMontiel, AV;Montal, M
离子型谷氨酸受体是介导中枢神经系统兴奋性突触传递的神经递质激活的离子通道，是未知亚基化学计量的寡聚膜蛋白，为了确定亚基化学计量，我们使用了基于两个α-氨基-3-羟基-5-甲基-4-异恶唑丙酸酯/红藻氨酸受体亚基1（GluR 1）的阻断的功能测定。选择性工程改造的突变亚基对开放通道阻断剂苯环利定和地唑平（MK-801）表现出不同的敏感性，将弱敏感性与高敏感性亚基互补RNA共注射到两栖动物卵母细胞中产生具有混合阻断剂敏感性的功能性异聚体通道，增加的高度敏感的亚基的分数增强药物敏感的受体的比例，使用基于随机聚集的受体亚基的模型的数据分析，使我们能够确定一个五聚体的GluR 1的化学计量。这一发现支持了这样的观点，即五聚体亚基组织的神经元离子型谷氨酸受体基因家族的结构。
Ionotropic glutamate receptors, neurotransmitter-activated ion channels that mediate excitatory synaptic transmission in the central nervous system, are oligomeric membrane proteins of unknown subunit stoichiometry, To determine the subunit stoichiometry we have used a functional assay based on the blockade of two alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor subunit 1 (GluR1) mutant subunits selectively engineered to exhibit differential sensitivity to the open channel blockers phencyclidine and dizolcipine (MK-801), Coinjection into amphibian oocytes of weakly sensitive with highly sensitive subunit complementary RNAs produces functional heteromeric channels with mixed blocker sensitivities, Increasing the fraction of the highly sensitive subunit augmented the proportion of drug-sensitive receptors, Analysis of the data using a model based on random aggregation of receptor subunits allowed us to determine a pentameric stoichiometry for GluR1. This finding supports the view that a pentameric subunit organization underlies the structure of the neuronal ionotropic glutamate receptor gene family.