Wu X, Prasad P D, Leibach F H, Ganapathy V
Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912, USA.
Biochem Biophys Res Commun. 1998 May 29;246(3):589-95. doi: 10.1006/bbrc.1998.8669.
We have cloned OCTN2, a new member of the organic cation transporter family, from a human placental trophoblast cell line. The hOCTN2 cDNA codes for a protein of 557 amino acids with twelve putative transmembrane domains. The octn2 gene, located on human chromosome 5q31, consists of ten exons. The OCTN2-specific transcript, 3.5 kb in size, is expressed widely in human tissues and in cell lines of human origin. At the level of amino acid sequence, OCTN2 is more closely related to OCTN1 than to OCT1, OCT2 and OCT3. When expressed heterologously in HeLa cells, OCTN2 mediates the transport of tetraethylammonium, a prototypical organic cation, in a pH-dependent manner. Several organic cations, including the neurotoxins 1-methyl-4-phenylpyridinium, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and methamphetamine, compete for the OCTN2-mediated transport process.
我们从人胎盘滋养层细胞系中克隆出有机阳离子转运体家族的一个新成员OCTN2。hOCTN2 cDNA编码一种含557个氨基酸的蛋白质，有12个推定的跨膜结构域。位于人类5号染色体q31的octn2基因由10个外显子组成。大小为3.5 kb的OCTN2特异性转录本在人类组织和人源细胞系中广泛表达。在氨基酸序列水平上，OCTN2与OCTN1的关系比与OCT1、OCT2和OCT3的关系更密切。当在HeLa细胞中异源表达时，OCTN2以pH依赖的方式介导原型有机阳离子四乙铵的转运。几种有机阳离子，包括神经毒素1-甲基-4-苯基吡啶鎓、1-甲基-4-苯基-1,2,3,6-四氢吡啶和甲基苯丙胺，竞争OCTN2介导的转运过程。
