Molecular cloning of an anuran V2 type [Arg8] vasotocin receptor and mesotocin receptor:: functional characterization and tissue expression in the Japanese tree frog (Hyla japonica)
Molecular cloning of an anuran V2 type [Arg8] vasotocin receptor and mesotocin receptor:: functional characterization and tissue expression in the Japanese tree frog (Hyla japonica)
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DOI：
10.1016/s0016-6480(03)00140-0
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发表时间：
2003-07-01
影响因子：
2.7
通讯作者：
Iguchi, T
中科院分区：
文献类型：
--
作者：
Kohno, S;Kamishima, Y;Iguchi, T
在大多数两栖动物中，[Arg(8)] 催产素 (VT) 具有抗利尿作用，该作用与腺苷酸环化酶的激活有关。相比之下，中产素 (MT) 具有利尿作用，并通过两栖动物中的磷酸肌醇/钙信号通路发挥作用。为了进一步阐明 VT 和 MT 激活的机制，我们报告了来自日本树蛙 Hyla japonica 的 VT 受体（VTR）和 MT 受体（MTR）的分子克隆。树蛙VTR或MTR cDNA编码363或389个氨基酸，其氨基酸序列分别与哺乳动物加压素V-2（51-52％同一性）或蟾蜍MT（94％同一性）受体非常相似。使用转染树蛙VTR的CHO-K1细胞，我们观察到细胞暴露于VT或其他神经垂体激素后细胞内cAMP浓度升高，而转染MTR的细胞并未表现出cAMP浓度改变。用VTR转染的细胞表现出以下cAMP积累效率：VT = Hydrin 1 大于或等于Hydrin 1 大于或等于Hydrin 2 > MT = 催产素> 异产素。 VTR 或 MTR mRNA 分别表现出单个 2.2-kb 或 5.5-kb 转录带，并且两者均在各种组织中表达。 VTR mRNA 在脑、心脏、肾、骨盆皮肤斑和膀胱中清晰表达，而脑、脂肪体、心脏、肾和膀胱表达 MTR mRNA。具体而言，骨盆斑块中的 VTR mRNA 或背部皮肤中的 MTR mRNA 在皮肤中的水平升高。 VTR 和 MTR 在渗透调节器官上的特征分布表明这些受体的配体将介导多种功能。此外，VTR在皮肤中的分布会导致日本树蛙皮肤吸水率对VT的反应存在区域差异。 (C) 2003 年爱思唯尔科学（美国）。版权所有。
In most amphibians, [Arg(8)] vasotocin (VT) has an antidiuretic effect that is coupled to the activation of adenylate cyclase. In contrast, mesotocin (MT) has a diuretic effect and acts via the inositol phosphate/calcium signaling pathway in amphibians. To further clarify the mechanisms of VT and MT activation, we report the molecular cloning of a VT receptor (VTR) and a MT receptor (MTR) from the Japanese tree frog, Hyla japonica. Tree frog VTR or MTR cDNA encoded 363 or 389 amino acids, and their amino acid sequences revealed close similarity to the mammalian vasopressin V-2 (51-52% identity) or toad MT (94% identity) receptors, respectively. Using CHO-K1 cells transfected with tree frog VTR, we observed elevated concentrations of intracellular cAMP following exposure of the cells to VT or other neurohypophysial hormones, whereas the cells transfected with MTR did not exhibit altered cAMP concentrations. The cells transfected with VTR exhibited the following efficiency for cAMP accumulation: VT = hydrin 1 greater than or equal to vasopressin greater than or equal to hydrin 2 > MT = oxytocin > isotocin. VTR or MTR mRNA exhibits a single 2.2- or 5.5-kb transcription band, respectively, and both are expressed in various tissues. VTR mRNA is clearly expressed in brain, heart, kidney, pelvic patch of skin, and urinary bladder, whereas brain, fat body, heart, kidney, and urinary bladder express MTR mRNA. Specifically, VTR mRNA in the pelvic patch or MTR mRNA in the dorsal skin is present at elevated levels in the skin. Characteristic distribution of VTR and MTR on osmoregulating organs indicates the ligands for these receptors would mediate a variety of functions. Further, the distribution of VTR in the skin would make the regional difference on cutaneous water absorption in response to VT in the Japanese tree frog. (C) 2003 Elsevier Science (USA). All rights reserved.