Laz T M, Forray C, Smith K E, Bard J A, Vaysse P J, Branchek T A, Weinshank R L
Synaptic Pharmaceutical Corporation, Paramus, New Jersey 07652.
Mol Pharmacol. 1994 Sep;46(3):414-22.
The cDNA for the rat alpha 1c-adrenergic receptor (AR) has been cloned using a probe derived from the bovine alpha 1c-AR sequence. Clone rB7a has a 2.6-kilobase insert with a 1390-base pair open reading frame and encodes a receptor of 466 amino acids. The cloned receptor has 91% amino acid identity with the bovine alpha 1c-AR. The rat alpha 1c-AR mRNA was detected in tissues known to be enriched for the alpha 1A-AR subtype, including vas deferens, heart, kidney, and hippocampus. Rat alpha 1c-AR mRNA was absent from liver and spleen when assayed by Northern blot analyses and RNase protection assays. In COS-7 cells transfected with cDNAs encoding the three rat alpha 1-ARs, WB-4101 and benoxathian had similar binding affinities for the alpha 1a/d-AR and the alpha 1c-AR and 10-fold lower affinities for the alpha 1b-AR. The affinity of 5-methylurapidil was found to be 10- and 30-fold higher at the alpha 1c-AR than at the alpha 1a/d- and alpha 1b-ARs, respectively. (S)-(+)-Niguldipine was found to have high affinity for the rat alpha 1c-AR, with 42- and 22-fold lower affinity at the alpha 1a/d- and alpha 1b-ARs, respectively. Treatment of intact transfected COS-7 cells with chlorethylclonidine resulted in the inactivation of 19% of the alpha 1c-ARs, in contrast to 72% and 85% inactivation of the alpha 1a/d- and alpha 1b-ARs, respectively. Similarly to the other two alpha 1-ARs, the rat alpha 1c-AR is coupled to the activation of phospholipase C. Our data suggest that the rat alpha 1c-AR cDNA encodes an alpha 1-AR with the pharmacological properties previously defined for the alpha 1A subtype found in tissues.
利用源自牛α1c - 肾上腺素能受体（AR）序列的探针克隆了大鼠α1c - 肾上腺素能受体的互补DNA（cDNA）。克隆体rB7a有一个2.6千碱基的插入片段，带有一个1390碱基对的开放阅读框，编码一个由466个氨基酸组成的受体。克隆的受体与牛α1c - AR有91%的氨基酸同一性。在已知富含α1A - AR亚型的组织中检测到大鼠α1c - AR信使核糖核酸（mRNA），包括输精管、心脏、肾脏和海马体。通过Northern印迹分析和核糖核酸酶保护试验检测时，肝脏和脾脏中没有大鼠α1c - AR mRNA。在用编码三种大鼠α1 - AR的cDNA转染的COS - 7细胞中，WB - 4101和贝诺沙噻对α1a/d - AR和α1c - AR具有相似的结合亲和力，而对α1b - AR的亲和力低10倍。发现5 - 甲基尿嘧啶在α1c - AR上的亲和力分别比在α1a/d - AR和α1b - AR上高10倍和30倍。发现（S）-（+）-尼鲁地平对大鼠α1c - AR具有高亲和力，在α1a/d - AR和α1b - AR上的亲和力分别低42倍和22倍。用氯乙可乐定处理完整的转染COS - 7细胞导致19%的α1c - AR失活，相比之下，α1a/d - AR和α1b - AR的失活率分别为72%和85%。与其他两种α1 - AR类似，大鼠α1c - AR与磷脂酶C的激活偶联。我们的数据表明，大鼠α1c - AR cDNA编码一种具有先前在组织中定义的α1A亚型药理学特性的α1 - AR。
