Sequence and chromosomal assignment of a human novel cDNA: similarity to gamma-aminobutyric acid transporter
Sequence and chromosomal assignment of a human novel cDNA: similarity to gamma-aminobutyric acid transporter
复制标题
DOI：
10.1139/cjpp-79-12-977
复制
发表时间：
2001-12-01
影响因子：
2.1
通讯作者：
Minuk, GY
中科院分区：
文献类型：
--
作者：
Gong, YW;Zhang, MN;Minuk, GY
γ-氨基丁酸(GABA)是哺乳动物大脑中主要的抑制性神经递质。虽然最初被认为仅限于中枢神经系统，但GABA能活动也在全身其他组织中被描述。在本研究中，我们报道了人GABA转运蛋白基因的克隆和定位，并记录了其在人体不同组织中的表达。用P-32标记的小鼠脑内GABA转运蛋白3(GAT-3)的cDNA探针初步筛选人肝脏的cDNA文库，并利用Marathon-Ready(TM)人肾的全长cDNA克隆了人肝脏的全长cDNA。人GABA转运蛋白基因编码569个氨基酸的疏水蛋白，有12个跨膜区(TM)。对已发表的序列进行搜索，发现其与大鼠GAT-2、小鼠GAT-3、人溶质载体家族6成员13(SLC6A13)和人外周甜菜碱/GABA转运体具有高度的同源性。Northern印迹分析表明，人的GABA转运蛋白在肾脏中表达强烈，在肝脏和大脑中表达较少。该序列与人染色体12p13.3完全匹配，提示人GABA转运蛋白含有14个外显子。上述发现证实了人类组织中存在一种特定的GABA转运蛋白，并进一步确定了其特征。
Gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the mammalian brain. Although initially thought to be confined to the central nervous system, GABAergic activity has also been described in other tissues throughout the body. In the present study, we report the cloning and localization of human GABA transporter cDNA and document its expression in various human tissues. A human liver cDNA library was initially screened by a P-32-labeled murine brain GABA transporter 3 (GAT-3) cDNA probe, and full-length cDNA was cloned by employing Marathon-Ready(TM) human kidney cDNA. The human GABA transporter cDNA encoded a 569 amino acid hydrophobic protein with 12 transmembrane domains (TMs). Search of published sequences revealed high homology with rat GAT-2, murine GAT-3 cDNA, human solute carrier family 6 member 13 (SLC6A13), and a human peripheral betaine/GABA transporter. Northern blot analyses demonstrated that the human GABA transporter is expressed strongly in the kidney and to a lesser extent in the liver and brain. The sequence was well matched with human chromosome 12p13.3, suggesting the human GABA transporter contains 14 exons. The above findings confirm the existence of and further characterize a specific GABA transporter in human tissues.