Molecular cloning of urea transporters from the kidneys of baleen and toothed whales
Molecular cloning of urea transporters from the kidneys of baleen and toothed whales
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DOI：
10.1016/j.cbpb.2006.11.033
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发表时间：
2008-02-01
影响因子：
2.2
通讯作者：
Urano, Akihisa
中科院分区：
文献类型：
--
作者：
Birukawa, Naoko;Ando, Hironori;Urano, Akihisa
肾脏中的尿素转运对于浓缩尿的产生很重要。这一过程由两个基因UT-A（Slc 14 a2）和UT-B（Slc 14 a1）编码的尿素转运蛋白（UTs）介导。我们以前的研究表明，鲸目动物比陆地哺乳动物产生高浓度的尿液，须鲸比抹香鲸显示出更高浓度的尿尿素。因此，我们假设鲸类具有独特的UTs行动，以维持海洋栖息地的流体稳态。本文报道了尖吻须鲸（Balaenoptera acutorostrata），sei（B. borealis）、Bryde's（B. brydei）和抹香鲸（Physeter macrocephalus）的基因组序列，以确定编码UT的mRNA的核苷酸序列。2.5kb的cDNA序列编码397个氨基酸的蛋白质，其与哺乳动物UT-A2具有90-94%的同一性。两个假定的糖基化位点之间的鲸鱼和陆地哺乳动物是保守的，而蛋白激酶的共识网站是不完全保守的，只有一个单一的蛋白激酶A共识网站被确定在鲸鱼UT-A2。两个蛋白激酶C的共识网站存在于须鲸UT A2，然而，一个单一的蛋白激酶C的共识网站被确定在抹香鲸UT-A2。鲸鱼UT-A2的这些不同的磷酸化位点可能通过反映它们的尿素渗透性而导致鲸鱼中尿尿素的高浓度。(C)2007爱思唯尔公司All rights reserved.
Urea transport in the kidney is important for the production of concentrated urine. This process is mediated by urea transporters (UTs) encoded by two genes, UT-A (Slc14a2) and UT-B (Slc14a1). Our previous study demonstrated that cetaceans produce highly concentrated urine than terrestrial mammals, and that baleen whales showed higher concentrations of urinary urea than sperm whales. Therefore, we hypothesized that cetaceans have unique actions of UTs to maintain fluid homeostasis in marine habitat. Kidney samples of common minke (Balaenoptera acutorostrata), sei (B. borealis), Bryde's (B. brydei) and sperm whales (Physeter macrocephalus) were obtained to determine the nucleotide sequences of mRNAs encoding UT. The sequences of 2.5-kb cDNAs encode 397-amino acid proteins, which are 90-94% identical to the mammalian UT-A2s. Two putative glycosylation sites are conserved between the whales and the terrestrial mammals, whereas consensus sites for protein kinases are not completely conserved; only a single protein kinase A consensus site was identified in the whale UT-A2s. Two protein kinase C consensus sites are present in the baleen whale UT A2s, however, a single protein kinase C consensus site was identified in the sperm whale UT-A2. These different phosphorylation sites of whale UT-A2s may result in the high concentrations of urinary urea in whales, by reflecting their urea permeability. (C) 2007 Elsevier Inc. All rights reserved.