Molecular cloning of bullfrog D2 dopamine receptor cDNA: Tissue distribution of three isoforms of D2 dopamine receptor mRNA
Molecular cloning of bullfrog D2 dopamine receptor cDNA: Tissue distribution of three isoforms of D2 dopamine receptor mRNA
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DOI：
10.1016/j.ygcen.2010.04.016
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发表时间：
2010-08-01
影响因子：
2.7
通讯作者：
Kobayashi, Tetsuya
中科院分区：
文献类型：
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作者：
Nakano, Masaki;Hasunuma, Itaru;Kobayashi, Tetsuya
从牛蛙脑垂体远端叶中克隆了编码D2多巴胺受体的基因。牛蛙02多巴胺受体(BfD2a)的氨基酸序列由444个氨基酸组成，具有其他动物所克隆的D2受体的典型特征。它与大鼠、火鸡、非洲爪哇和罗非鱼的相似性高达75%-87%。进一步的核苷酸序列分析表明，该基因含有D2多巴胺受体亚型bfD2B和bfD2C，其核苷酸序列分别缺少bfD2A编码区的12和99个核苷酸。序列比对分析表明，bfD2C亚型与在哺乳动物和鸟类中克隆的D2(S)亚型相近，而bfD2A和bfD2B亚型与哺乳动物和禽类D2(L)亚型相近，与非洲爪哇的两种亚型同源。这是首次报道在同一物种中存在两个D2(L)样异构体和一个D2(S)样异构体的mRNAs。负责产生异构体的氨基酸序列存在于第三胞内环，已被证明在与G蛋白的偶联中发挥重要作用。因此，三种异构体与G蛋白的偶联方式存在差异。用RT-PCR方法分析三种异构体在器官和组织中的表达。在脑、远侧部和神经中间部，三种异构体的mRNAs均有表达，而外周器官和组织中只有bfD2CmRNAs的表达。(C)2010 Elsevier Inc.保留所有权利。
The cDNA encoding D2 dopamine receptor was cloned from the distal lobe of the bullfrog pituitary. The deduced amino acid sequence of the bullfrog 02 dopamine receptor (bfD2A) spanned 444 amino acids and exhibited typical features of those of D2 dopamine receptors cloned in other animals to date. It showed a high similarity of 75-87% with rat, turkey, Xenopus and tilapia counterparts. Further analysis of nucleotide sequence of the cDNA revealed the presence of putative truncated D2 dopamine receptor isoforms, bfD2B and bfD2C, of which nucleotide sequences lacked 12 and 99 nucleotides of the coding region for bfD2A, respectively. The alignment analysis indicated that putative bfD2C isoform was close to D2(S) subtype cloned in mammals and birds, whereas bfD2A and putative bfD2B isoforms were close to mammalian and avian D2(L), subtype and homologous to two isoforms of Xenopus. This is the first report of the presence of mRNAs for two D2(L)-like isoforms and one D2(S)-like isoform in a single species. The amino acid sequence responsible for producing isoforms is present in the third intracellular loop, which has been shown to play an important role in the coupling with G protein. Accordingly, differences in the mode of coupling with G protein among three isoforms were suggested. The expression of three isoforms mRNA in organs and tissues was analyzed by RT-PCR. In the brain, pars distalis and pars neurointermedia, mRNAs for three isoforms were invariably expressed, whereas only putative bfD2C mRNA was expressed in peripheral organs and tissues. (C) 2010 Elsevier Inc. All rights reserved.