The relative amount of cRNA coding for γ2 subunits affects stimulation by benzodiazepines in GABAA receptors expressed in Xenopus oocytes
The relative amount of cRNA coding for γ2 subunits affects stimulation by benzodiazepines in GABAA receptors expressed in Xenopus oocytes
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DOI：
10.1016/s0028-3908(02)00036-9
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发表时间：
2002-09-01
影响因子：
4.7
通讯作者：
Czajkowski, C
中科院分区：
文献类型：
--
作者：
Boileau, AJ;Baur, R;Czajkowski, C
重组GABA（A）受体中GABA激活的Cl-电流（I-GABA）的苯二氮卓（BZD）增强作用需要γ亚基的存在。当α 1、β 2和γ 2S cRNA在非洲爪蟾卵母细胞中以1：1：1的比例表达时，I-GABA的BZD增强作用是次最大的、可变的并随时间减弱。通过增加编码γ 2S亚基的cRNA的相对量，BZD的增强作用增加，更具重现性，并随时间推移而稳定。此外，α 1 β 2 γ 2（1：1：1）受体的GABA EC 50值介于α 1 β 2（1：1）和α 1 β 2 γ 2（1：1：10）受体的测量值之间。我们的结论是，共同表达的α 1，β 2和γ 2亚基在非洲爪蟾卵母细胞的相等比例产生的混合人口的α 1 β 2和α 1 β 2 γ 2受体。因此，为了准确测量BZD增强作用，有必要注射相对于α 1和β 2 cRNA更高比例的γ 2亚基cRNA。这导致更纯的α 1 β 2 γ 2受体群体。(C)2002爱思唯尔科技有限公司。保留所有权利。
Benzodiazepine (BZD) potentiation of GABA-activated Cl--current (I-GABA) in recombinant GABA(A) receptors requires the presence of the 7 subunit, When (alpha1, beta2 and gamma2S cRNA are expressed in a 1: 1: 1 ratio in Xenopus oocytes, BZD potentiation of I-GABA is submaximal, variable and diminishes over time. Potentiation by BZDs is increased, more reproducible and is stabilized over time by increasing the relative amount of cRNA coding for the gamma2S subunit. In addition, GABA EC50 values for alpha1beta2gamma2 (1:1:1) receptors are intermediate to values measured for alpha1beta2 (1:1) and (alpha1beta2gamma2 (1:1:10) receptors. We conclude that co-expression of equal ratios of alpha1, beta2 and gamma2 subunits in Xenopus oocytes produces a mixed population of alpha1beta2 and alpha1beta2gamma2 receptors. Therefore, for accurate measurements of BZD potentiation it is necessary to inject a higher ratio of gamma2 subunit cRNA relative to alpha1 and beta2 cRNA. This results in a purer population of alpha1beta2gamma2 receptors. (C) 2002 Elsevier Science Ltd. All rights reserved.