Zeng D W, Harrison J K, D'Angelo D D, Barber C M, Tucker A L, Lu Z H, Lynch K R
Department of Pharmacology, University of Virginia School of Medicine, Charlottesville 22908.
Proc Natl Acad Sci U S A. 1990 Apr;87(8):3102-6. doi: 10.1073/pnas.87.8.3102.
Alpha 2-adrenergic receptors comprise a heterogeneous population based on pharmacologic and molecular evidence. We have isolated a cDNA clone (pRNG alpha 2) encoding a rat alpha 2-adrenergic receptor. A rat kidney cDNA library was screened with an oligonucleotide complementary to a highly conserved region found in all biogenic amine receptors described to date. The deduced amino acid sequence displays many features of guanyl nucleotide-binding protein-coupled receptors except it does not have a consensus N-linked glycosylation site near the amino terminus. Membranes prepared from COS cells transfected with pRNG alpha 2 DNA display high affinity and saturable binding to [3H]rauwolscine (Kd = 2 nM). Competition curve data analysis shows that RNG alpha 2 protein binds to a variety of adrenergic drugs with the following rank order of potency: yohimbine greater than or equal to chlorpromazine greater than or equal to prazosin greater than or equal to clonidine greater than norepinephrine greater than or equal to oxymetazoline. RNG alpha 2 RNA accumulates in both rat kidney and neonatal rat lung (predominant species is 4000 nucleotides). When a cysteine residue (Cys-169) that is conserved among all members of the seven-transmembrane-region superfamily is changed to phenylalanine, the RNG alpha 2 protein fails to bind [3H]rauwolscine after expression in COS cells. We conclude that pRNG alpha 2 likely represents a cDNA for a rat alpha 2B-adrenergic receptor.
基于药理学和分子学证据，α2 - 肾上腺素能受体构成了一个异质群体。我们分离出了一个编码大鼠α2 - 肾上腺素能受体的cDNA克隆（pRNGα2）。用与迄今为止所描述的所有生物胺受体中一个高度保守区域互补的寡核苷酸筛选大鼠肾脏cDNA文库。推导的氨基酸序列显示出许多鸟苷酸结合蛋白偶联受体的特征，但在氨基末端附近没有一致的N - 连接糖基化位点。用pRNGα2 DNA转染的COS细胞制备的膜对[3H]育亨宾显示出高亲和力和可饱和结合（Kd = 2 nM）。竞争曲线数据分析表明，RNGα2蛋白与多种肾上腺素能药物结合，其效力顺序如下：育亨宾≥氯丙嗪≥哌唑嗪≥可乐定≥去甲肾上腺素≥羟甲唑啉。RNGα2 RNA在大鼠肾脏和新生大鼠肺中均有积累（主要种类为4000个核苷酸）。当七跨膜区超家族所有成员中保守的一个半胱氨酸残基（Cys - 169）变为苯丙氨酸时，RNGα2蛋白在COS细胞中表达后不能结合[3H]育亨宾。我们得出结论，pRNGα2可能代表大鼠α2B - 肾上腺素能受体的一个cDNA。
