Structure, tissue expression pattern, and function of the amino acid transporter rat PAT2
Structure, tissue expression pattern, and function of the amino acid transporter rat PAT2
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DOI：
10.1016/s0006-291x(03)00648-x
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发表时间：
2003-05-16
影响因子：
3.1
通讯作者：
Thwaites, DT
中科院分区：
文献类型：
--
作者：
Chen, Z;Kennedy, DJ;Thwaites, DT
从大鼠肺cDNA文库中分离出H+偶联、pH依赖性、Na+非依赖性氨基酸转运蛋白PAT（质子偶联氨基酸转运蛋白）家族的第二个成员。大鼠PAT 2基因cDNA全长2396 bp，包括70 bp的5 '非翻译区和一个poly（A）尾。转运蛋白基因位于大鼠染色体10 q22上，由10个外显子组成。该cDNA编码481个氨基酸的蛋白质，与大鼠PAT 1具有72%的同一性（超过449个氨基酸）。组织表达研究表明，mRNA丰度通常较低，在肺和脾中检测到最高水平，在脑、心脏、肾和骨骼肌中检测到较低水平。在哺乳动物细胞或非洲爪蟾卵母细胞中的功能表达表明，大鼠PAT 2介导甘氨酸、脯氨酸和α（甲基）氨基异丁酸（MeAIB）的pH依赖性、Na+非依赖性摄取。总之，与PAT 1相比，PAT 2具有有限的组织分布、更高的亲和力（甘氨酸摄取的Michaelis-Menten常数在0.49和0.69 mM之间）和不同的底物特异性。(C)2003 Elsevier Science（美国）。All rights reserved.
The second member of the PAT (proton-coupled amino acid transporter) family of H+-coupled, pH-dependent, Na+-independent amino acid transporters was isolated from a rat lung cDNA library. The cDNA for rat PAT2 is 2396 bp in length, including 70 bp of 5'UTR and a poly(A) tail. The transporter gene, consisting of 10 exons, is located on rat chromosome 10q22. The cDNA codes for a protein of 481 amino acids with 72% identity (over 449 amino acids) with rat PAT1. Tissue expression studies demonstrate that mRNA abundance is generally low with highest levels being detected in lung and spleen, with lower levels in the brain, heart, kidney, and skeletal muscle. Functional expression in either mammalian cells or Xenopus laevis oocytes demonstrates that rat PAT2 mediates pH-dependent, Na+-independent uptake of glycine, proline, and alpha(methyl)aminoisobutyric acid (MeAIB). In conclusion PAT2 has a limited tissue distribution, higher affinity (Michaelis-Menten constant for glycine uptake between 0.49 and 0.69 mM), and distinct substrate specificity compared to PAT1. (C) 2003 Elsevier Science (USA). All rights reserved.