Noble P J, Anderson S M, De Souza R J, Cross A J, Stephenson F A
Department of Pharmaceutical Chemistry, School of Pharmacy, London, England.
J Neurochem. 1993 Aug;61(2):752-5. doi: 10.1111/j.1471-4159.1993.tb02182.x.
A previous report has described the presence of t-[35S]-butylbicyclophosphorothionate binding sites and GABA-gated Cl- flux in the human neuroblastoma IMR-32 cell line. We now report the further characterisation of this binding site and, even more important, the identification of the GABAA receptor alpha 3 sub-unit expressed in these cells. Cell membranes prepared from IMR-32 cells were screened by immunoblotting for reactivity with various GABAA receptor alpha subunit-specific antibodies. Of these, only anti-Cys alpha 3 454-467 antibodies recognised specifically and in a dose-dependent manner an immunoreactive band. This M(r) 58,000 immunoreactive species and the N-deglycosylated derivatives were both coincident with the respective homologues found in both calf cerebral cortex membranes and purified receptor preparations. This is the first report of the identification of a specific GABAA receptor subunit expressed in a human cell line, and it therefore provides a convenient model for the study of receptor structure and regulation.
先前的一份报告描述了在人神经母细胞瘤IMR - 32细胞系中存在t - [35S] - 丁基双环硫代磷酸酯结合位点以及GABA门控的Cl-通量。我们现在报告该结合位点的进一步特征，更重要的是，鉴定这些细胞中表达的GABAA受体α3亚基。通过免疫印迹法筛选从IMR - 32细胞制备的细胞膜，以检测其与各种GABAA受体α亚基特异性抗体的反应性。其中，只有抗Cysα3 454 - 467抗体能特异性地、以剂量依赖的方式识别一条免疫反应带。这种分子量为58,000的免疫反应性物质及其N - 去糖基化衍生物与在小牛大脑皮层膜和纯化的受体制剂中发现的各自同源物均一致。这是首次在人细胞系中鉴定出特定GABAA受体亚基的报告，因此它为研究受体结构和调节提供了一个便利的模型。
