Chen Y, Mestek A, Liu J, Yu L
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis 46202.
Biochem J. 1993 Nov 1;295 ( Pt 3)(Pt 3):625-8. doi: 10.1042/bj2950625.
By screening a rat brain cDNA library using a cloned mu opioid receptor cDNA as probe, a clone was identified that is very similar to both the mu and delta opioid receptor sequences. Transient expression of this clone in COS-7 cells showed that it encodes a kappa opioid receptor, designated KOR-1, which is capable of high-affinity binding to kappa-selective ligands. Treatment of transfected cell membranes with bremazocine, a kappa-selective agonist, resulted in a 53% decrease in adenylate cyclase activity, indicating that this kappa opioid receptor displays inhibitory coupling to adenylate cyclase. Thus, one member from each of the three opioid receptor types, mu, kappa and delta, has been molecularly cloned. Analysis of sequence similarities among these opioid receptors, as well as between opioid receptors and other G-protein-coupled receptors, revealed regions of sequence conservation that may underlie the ligand-binding and functional specificities of opioid receptors.
通过使用克隆的μ阿片受体cDNA作为探针筛选大鼠脑cDNA文库，鉴定出一个与μ和δ阿片受体序列都非常相似的克隆。该克隆在COS-7细胞中的瞬时表达表明它编码一种κ阿片受体，命名为KOR-1，它能够与κ选择性配体进行高亲和力结合。用κ选择性激动剂布马佐辛处理转染的细胞膜，导致腺苷酸环化酶活性降低53%，表明这种κ阿片受体与腺苷酸环化酶呈抑制性偶联。因此，μ、κ和δ这三种阿片受体类型中的每一种都有一个成员已被分子克隆。对这些阿片受体之间以及阿片受体与其他G蛋白偶联受体之间的序列相似性分析，揭示了可能是阿片受体配体结合和功能特异性基础的序列保守区域。
