Meng F, Xie G X, Chalmers D, Morgan C, Watson S J, Akil H
Mental Health Research Institute, University of Michigan, Ann Arbor 48109.
Brain Res Mol Brain Res. 1994 Oct;26(1-2):143-55. doi: 10.1016/0169-328x(94)90085-x.
Three full-length cDNA clones encoding the guinea pig A1 adenosine receptor have been isolated by polymerase chain reaction (PCR) and low-stringency hybridization screening of a guinea pig brain cDNA library. These three cDNAs, though differing in their 5' untranslated regions, contain the same open reading frame encoding a 326 amino acid residue protein with seven hydrophobic alpha-helices long enough to form the transmembrane domains, suggesting that it belongs to the G protein-coupled receptor superfamily. This protein is highly homologous to the A1 adenosine receptors previously cloned from other species. Pharmacological characterization of this receptor transiently expressed in mammalian cells demonstrates that, despite its high homology to A1 adenosine receptors of other species, the guinea pig A1 adenosine receptor displays a unique pharmacological profile: high affinity for the A1-selective antagonist CPX, yet very low affinity for some A1-selective agonists such as CCPA, CHA and R-PIA. Northern blotting for different guinea pig tissues and in situ hybridization for guinea pig brain sections reveal an abundant and broad distribution of mRNA of this A1 subtype receptor in the brain.
通过聚合酶链反应（PCR）和对豚鼠脑cDNA文库进行低严谨度杂交筛选，已分离出三个编码豚鼠A1腺苷受体的全长cDNA克隆。这三个cDNA虽然在其5'非翻译区有所不同，但包含相同的开放阅读框，编码一个326个氨基酸残基的蛋白质，该蛋白质具有七个足够长的疏水α-螺旋以形成跨膜结构域，表明它属于G蛋白偶联受体超家族。该蛋白质与先前从其他物种克隆的A1腺苷受体高度同源。对在哺乳动物细胞中瞬时表达的该受体进行药理学表征表明，尽管豚鼠A1腺苷受体与其他物种的A1腺苷受体高度同源，但它显示出独特的药理学特征：对A1选择性拮抗剂CPX具有高亲和力，但对一些A1选择性激动剂如CCPA、CHA和R-PIA的亲和力非常低。对不同豚鼠组织进行Northern印迹分析以及对豚鼠脑切片进行原位杂交显示，该A1亚型受体的mRNA在脑中分布丰富且广泛。
