Wang H, Singh D, Yang W, Dyck J R, Fliegel L
Department of Biochemistry, Faculty of Medicine, University of Alberta, Edmonton, Canada.
Mol Cell Biochem. 1996 Dec 20;165(2):155-9. doi: 10.1007/BF00229478.
The Na+/H+ exchanger is a widely distributed integral membrane protein that is responsible for pH regulation in mammalian tissues. We have cloned and analyzed the NHE1 isoform of the mouse genomic Na+/H+ exchanger. A clone from a mouse genomic library contained the NHE1 promoter region and the 5'-untranslated region. It also contained the first 121 amino acids of the coding region of the Na+/H+ exchanger. A splice site occurred after amino acid 121, at the same region as in the human NHE1 gene. The deduced amino terminal coding sequence was 76 and 88% identical to the human and rat NHE1 sequences respectively. The 5'-untranslated region was highly homologous to that of other species and two minicistrons contained in the human Na+/H+ exchanger were present in the mouse sequence. The results show that the deduced protein sequence of the mouse NHE1 gene has a high level of homology with other species and that the splice site of the first intron is conserved. These results suggest that the first large intron may play an important role in the NHE1 gene expression.
钠氢交换体是一种广泛分布的整合膜蛋白，负责哺乳动物组织中的pH调节。我们已经克隆并分析了小鼠基因组钠氢交换体的NHE1亚型。从小鼠基因组文库中获得的一个克隆包含NHE1启动子区域和5'非翻译区。它还包含钠氢交换体编码区的前121个氨基酸。在第121个氨基酸之后出现了一个剪接位点，与人类NHE1基因中的区域相同。推导的氨基末端编码序列与人类和大鼠NHE1序列的同源性分别为76%和88%。5'非翻译区与其他物种的高度同源，并且人类钠氢交换体中包含的两个小顺反子存在于小鼠序列中。结果表明，小鼠NHE1基因推导的蛋白质序列与其他物种具有高度同源性，并且第一个内含子的剪接位点是保守的。这些结果表明，第一个大内含子可能在NHE1基因表达中起重要作用。
