Gorbulev V, Büchner H, Akhundova A, Fahrenholz F
Max-Planck-Institut für Biophysik, Frankfurt, Germany.
Eur J Biochem. 1993 Jul 1;215(1):1-7. doi: 10.1111/j.1432-1033.1993.tb18000.x.
[Arg8]vasopressin and oxytocin are the two main members of the neurohypophysial hormone family found to be present in nearly all mammals. [Lys8]vasopressin ([Lys8]VP) has been identified as the antidiuretic hormone in pig and some marsupial families. The porcine-derived kidney epithelial cell line, LLC-PK1, expresses both [Lys8]VP receptors coupled to the activation of adenylate cyclase (V2 receptors) and oxytocin receptors. Here we report the molecular cloning of the V2 [Lys8]VP receptor and the oxytocin receptor from LLC-PK1 cells. The cloned V2 [Lys8]VP receptor differs from human and rat V2 [Arg8] receptors mainly in its N-terminal region, in residues located in the extracellular loops and in intracellular phosphorylation sites. When expressed in COS7 cells, the V2 [Lys8]VP receptor exhibits the relative order of ligand affinity [Lys8]VP = [Arg8]VP >> 1-deamino[D-Arg8]VP > or = oxytocin and adenylate-cyclase stimulation, expected for the porcine V2 [Lys8]VP receptor but different from V2 [Arg8]VP receptors. Adenylate-cyclase activation by [Lys8]VP was inhibited in COS7 cells by a V2 antagonist. The cloned oxytocin receptor exhibits in COS7 cells a ligand specificity typical of mammalian oxytocin receptors. mRNA-distribution analysis revealed a single 5.5-kb transcript in the uterus from pregnant guinea pig.
[精氨酸8]加压素和催产素是在几乎所有哺乳动物中都存在的神经垂体激素家族的两个主要成员。[赖氨酸8]加压素（[赖氨酸8]VP）已被确定为猪和一些有袋类动物家族中的抗利尿激素。源自猪的肾上皮细胞系LLC-PK1表达与腺苷酸环化酶激活偶联的[赖氨酸8]VP受体（V2受体）和催产素受体。在此，我们报告了从LLC-PK1细胞中克隆V2[赖氨酸8]VP受体和催产素受体。克隆的V2[赖氨酸8]VP受体与人和大鼠的V2[精氨酸8]受体的主要差异在于其N端区域、位于细胞外环的残基以及细胞内磷酸化位点。当在COS7细胞中表达时，V2[赖氨酸8]VP受体表现出配体亲和力的相对顺序为[赖氨酸8]VP = [精氨酸8]VP >> 1-脱氨基[D-精氨酸8]VP ≥ 催产素以及腺苷酸环化酶刺激，这是猪V2[赖氨酸8]VP受体所预期的，但不同于V2[精氨酸8]VP受体。在COS7细胞中，[赖氨酸8]VP对腺苷酸环化酶的激活被V2拮抗剂抑制。克隆的催产素受体在COS7细胞中表现出典型的哺乳动物催产素受体的配体特异性。mRNA分布分析显示，怀孕豚鼠子宫中有一个单一的5.5 kb转录本。
