Ymer S, Schofield P R, Draguhn A, Werner P, Köhler M, Seeburg P H
Laboratory of Molecular Neuroendocrinology, University of Heidelberg, FRG.
EMBO J. 1989 Jun;8(6):1665-70. doi: 10.1002/j.1460-2075.1989.tb03557.x.
Cloned cDNAs encoding two new beta subunits of the rat and bovine GABAA receptor have been isolated using a degenerate oligonucleotide probe based on a highly conserved peptide sequence in the second transmembrane domain of GABAA receptor subunits. The beta 2 and beta 3 subunits share approximately 72% sequence identity with the previously characterized beta 1 polypeptide. Northern analysis showed that both beta 2 and beta 3 mRNAs are more abundant in the brain than beta 1 mRNA. All three beta subunit encoding cDNAs were also identified in a library constructed from adrenal medulla RNA. Each beta subunit, when co-expressed in Xenopus oocytes with an alpha subunit, forms functional GABAA receptors. These results, together with the known alpha subunit heterogeneity, suggest that a variety of related but functionally distinct GABAA receptor subtypes are generated by different subunit combinations.
利用基于γ-氨基丁酸A型（GABAA）受体亚基第二跨膜结构域高度保守肽序列的简并寡核苷酸探针，已分离出编码大鼠和牛GABAA受体两个新β亚基的克隆互补DNA（cDNA）。β2和β3亚基与先前鉴定的β1多肽具有约72%的序列同一性。Northern分析表明，β2和β3信使核糖核酸（mRNA）在脑中比β1 mRNA更为丰富。在由肾上腺髓质RNA构建的文库中也鉴定出了所有三个编码β亚基的cDNA。当每个β亚基与一个α亚基在非洲爪蟾卵母细胞中共表达时，均可形成功能性GABAA受体。这些结果，连同已知的α亚基异质性，表明不同的亚基组合可产生多种相关但功能不同的GABAA受体亚型。
