Xie G X, Meng F, Mansour A, Thompson R C, Hoversten M T, Goldstein A, Watson S J, Akil H
Mental Health Research Institute, University of Michigan, Ann Arbor 48109.
Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3779-83. doi: 10.1073/pnas.91.9.3779.
A full-length cDNA encoding the guinea pig kappa opioid (dynorphin) receptor has been isolated. The deduced protein contains 380 aa and seven hydrophobic alpha-helices characteristic of the G protein-coupled receptors. This receptor is 90% identical to the mouse and rat kappa receptors, with the greatest level of divergence in the N-terminal region. When expressed in COS-7 cells, the receptor displays high affinity and stereospecificity toward dynorphin peptides and other kappa-selective opioid ligands such as U50, 488. It does not bind the mu- and delta-selective opioid ligands. The expressed receptor is functionally coupled to G protein(s) to inhibit adenylyl cyclase and Ca2+ channels. The guinea pig kappa receptor mRNA is expressed in many brain areas, including the cerebellum, a pattern that agrees well with autoradiographic maps of classical guinea pig kappa binding sites. Species differences in the pharmacology and mRNA distribution between the cloned guinea pig and rat kappa receptors may be worthy of further examination.
编码豚鼠κ阿片样物质（强啡肽）受体的全长cDNA已被分离出来。推导的蛋白质含有380个氨基酸，具有G蛋白偶联受体特有的7个疏水α螺旋。该受体与小鼠和大鼠κ受体有90%的同一性，在N端区域差异最大。当在COS-7细胞中表达时，该受体对强啡肽肽和其他κ选择性阿片样物质配体（如U50,488）表现出高亲和力和立体特异性。它不结合μ和δ选择性阿片样物质配体。表达的受体在功能上与G蛋白偶联以抑制腺苷酸环化酶和Ca2+通道。豚鼠κ受体mRNA在包括小脑在内的许多脑区表达，这种模式与经典豚鼠κ结合位点的放射自显影片图谱非常吻合。克隆的豚鼠和大鼠κ受体在药理学和mRNA分布上的种属差异可能值得进一步研究。
