Molecular cloning and functional expression of cDNAs encoding a human Na+-nucleoside cotransporter (hCNT1).
Molecular cloning and functional expression of cDNAs encoding a human Na+-nucleoside cotransporter (hCNT1).
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DOI：
10.1152/ajpcell.1997.272.2.c707
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发表时间：
1997-02
期刊：
影响因子：
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通讯作者：
M. Ritzel;S. Yao;M.-Y. Huang;J. Elliott;C. Cass;J. Young
中科院分区：
文献类型：
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作者：
M. Ritzel;S. Yao;M.-Y. Huang;J. Elliott;C. Cass;J. Young
我们通过分子克隆和 cDNA 的功能表达鉴定了一种新的人类核苷转运蛋白。此前，我们使用非洲爪蟾卵母细胞中的表达选择从大鼠空肠上皮中分离出编码嘧啶选择性 Na+ 依赖性核苷转运蛋白 rCNT1 的 cDNA（Q.-Q. Huang、S. Y. M. Yao、M. W. L. Ritzel、A. R. P. Paterson、C. E. Cass 和 J. D. Young. J. Biol. Chem. 269： 17757-17760, 1994)。 rCNT1 的人类同源物（称为 hCNT1）的 cDNA 已通过杂交克隆和逆转录酶聚合酶链式反应扩增策略从人类肾脏中分离出来。 hCNT1 与 rCNT1 的氨基酸序列有 83% 的相同性，并且在非洲爪蟾卵母细胞中表达时，表现出 Na+ 依赖性核苷转运蛋白的转运特性，对嘧啶核苷和腺苷具有选择性。进行肾净分泌的脱氧腺苷和鸟苷的渗透物较差。然而，hCNT1 确实转运 3'-叠氮基-3'-脱氧胸苷。这是首次证明CNT家族成员存在于人体细胞中，并提供了它们参与生理核苷和核苷药物的肾脏转运的证据。 hCNT1 基因定位于染色体 15q25-26。
We report identification of a new human nucleoside transporter protein by molecular cloning and functional expression of its cDNA. Previously, we used expression selection in Xenopus oocytes to isolate a cDNA from rat jejunal epithelium encoding the pyrimidine-selective Na+-dependent nucleoside transporter rCNT1 (Q.-Q. Huang, S. Y. M. Yao, M. W. L. Ritzel, A. R. P. Paterson, C. E. Cass, and J. D. Young. J. Biol. Chem. 269: 17757-17760, 1994). cDNAs for a human homologue of rCNT1, designated hCNT1, have been isolated from human kidney by hybridization cloning and reverse transcriptase polymerase chain reaction amplification strategies. hCNT1 was 83% identical to rCNT1 in amino acid sequence and exhibited the transport characteristics of an Na+-dependent nucleoside transporter with selectivity for pyrimidine nucleosides and adenosine when expressed in Xenopus oocytes. Deoxyadenosine, which undergoes net renal secretion, and guanosine were poor permeants. hCNT1 did, however, transport 3'-azido-3'-deoxythymidine. This is the first demonstration that members of the CNT family exist in human cells and provides evidence of their involvement in the renal transport of physiological nucleosides and nucleoside drugs. The hCNT1 gene was mapped to chromosome 15q25-26.