Molecular mechanisms of drug transports via amino acid transporters

通过氨基酸转运蛋白转运药物的分子机制

• 批准号: 12670095
• 负责人: KANAI Yoshikatsu
• 金额: $ 2.56万
• 依托单位: Kyorin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670095/
• 关键词: transporter; amino acids; drug transport; thyroid hormone; triiodothyronine; melphalan; L-dopa; α-methyldopa; サイロキシン; 血液・脳関門; メチル水銀; モノカルボン酸

The purpose of this study is to reveal the mechanisms of drug transports via amino acid transporters. In this study, system L transporters LAT1 and LAT2 were investigated using Xenopus oocyte expression system, T24 human bladder carcinoma cells expressing high-level of LAT1 and mouse S2 cell-lines stably transfecting human LAT 1 and LAT2. It was demonstrated that LAT1 transports aromatic-amino-acid derivatives including L-dopa, α-methyldopa, α- methyltyrosine, gabapentin, thyroid hormones such as triiodothyronine and thyroxine, and anti-cancer drug melphalan. Based on the experimental and semi-empirical computational analyses, it is proposed that, in order for an aromatic amino acid to be a LAT1 substrate, it must have a free carboxyl and an amino group. In addition, the hydrophobic interaction between the substrate side chain and the substrate binding site of LAT1 seems to be crucial for the substrate binding. Because of this multispecific property, LAT1 has been established as a drug … More transporter.LAT1 has been demonstrated to be upregulated in cancer cells and its inhibition results in the inhibition of cancer cell growth. Based on the pharmacological properties of LAT1, we have designed and generated new compounds (KYT0193, KYT0206 and KYT0213) with high affinity to LATI, which can be candidates for anti-cancer agents.It has been proposed that the amino acid transporters are the major routes for methylmercury mobilization. In the present study it was found that LAT1 and LAT2 transport methylmercury as a cysteine-conjugate. We have further found that a classical system L inhibitor BCH rescued T24 human bladder carcinoma cells expressing LAT1 form the toxicity of methylmercury-cysteine conjugate, indicating that the cytotoxicity of methylmercury is mediated by system L transporters.In addition, we have identified novel aromatic amino acid transporter TAT1 (T-type amino acid transporter 1) and two members of heterodimeric amino acid transporters Asc-2 and AGT 1 proposed to be associated with unknown heavy chains. Less

本研究旨在揭示药物通过氨基酸转运体转运的机制。本研究利用非洲爪哇卵母细胞表达系统对系统L转运蛋白LAT1和LAT2、高水平表达LAT1的人膀胱癌T24细胞和稳定转染人LAT1和LAT2的小鼠S2细胞系进行了研究。研究表明，LAT1能转运L-多巴、α-甲基多巴、α-甲基酪氨酸、加巴喷丁等芳香族氨基酸衍生物、三碘甲腺原氨酸、甲状腺素等甲状腺激素以及抗癌药物马法兰。在实验和半经验计算分析的基础上，提出芳香族氨基酸作为LAT1底物必须含有游离的羧基和氨基。此外，LAT1的底物侧链和底物结合部位之间的疏水相互作用似乎是底物结合的关键。由于这种多特异性，LAT1已被确立为药物…更多的转运蛋白。LAT1已被证明在癌细胞中上调，其抑制结果是抑制癌细胞的生长。根据LAT1的药理性质，我们设计并合成了与Lati具有高亲和力的新化合物(KYT0193、KYT0206和KYT0213)，认为氨基酸转运体是甲基汞动员的主要途径。在目前的研究中，发现LAT1和LAT2以半胱氨酸偶联物的形式运输甲基汞。我们进一步发现经典的L系统抑制剂Bch使表达LAT1的T24人膀胱癌细胞免于甲基汞-半胱氨酸结合物的毒性，表明甲基汞的细胞毒性是由L系统转运蛋白介导的。此外，我们还鉴定了新的芳香族氨基酸转运蛋白TAT1(T型氨基酸转运蛋白1)和两个与未知重链相关的异二聚体氨基酸转运蛋白ASC-2和AGT1。较少

项目成果

Cha, S.H., Sekine, T., Fukushima, J., Kanai, Y., Kobayashi, Y., Goya, T., and Endou, H.: "Identification and characterization of human organic anion transporter 3 expressing predominantly in the kidney"Mol. Pharmacol. 59. 1277-1286 (2001)

Cha, S.H.、Sekine, T.、Fukushima, J.、Kanai, Y.、Kobayashi, Y.、Goya, T. 和 Endou, H.：“主要在肾脏表达的人类有机阴离子转运蛋白 3 的鉴定和表征

Nakajima, N: "Developmental changes in multispecific organic anion transporter 1 expression in the rat kidney"Kidney Int.. 57. 1608-1616 (2000)

Nakajima, N：“大鼠肾脏中多特异性有机阴离子转运蛋白 1 表达的发育变化”Kidney Int.. 57. 1608-1616 (2000)

Fukasawa,Y, Segawa,H, Kim,JY, Chairoungdua,A, Kim,DK, Matsuo,H, Cha,SH, Endou,H, and Kanai,Y: "ldentification and characterization of a Na^+-independent neutral amino acid transporter that associates with the 4F2 heavy chain and exhibits substrate selecti

Fukasawa,Y, Sekawa,H, Kim,JY, Chairoungdua,A, Kim,DK, Matsuo,H, Cha,SH, Endou,H 和 Kanai,Y：“Na^-独立中性氨基酸的鉴定和表征

Matsuo,H, Kanai,Y, Kim,JY, Chairoungdua,A, Kim,DK, inatomi,J, Shigeta,Y, Ishimine,H, Chaekuntode,S; Tachampa,K, Choi,HW, Babu,E, Fukuda,J, and Endou,H: "Identification of a novel Na^+-independent acidic amino acid transporter with structural similarity to

松尾，H，金井，Y，金，JY，Chairoungdua，A，Kim，DK，inatomi，J，Shigeta，Y，Ishimine，H，Chaekuntode，S；

Enomoto A, Wempe MF, Tsuchida H, Shin HJ, Cha SH, Anzai N, Goto A, Sakamoto A, Niwa T, Kanai Y, Anders MW, Endou H.: "Molecular identification of a novel carnitine transporter specific to human testis : Insights into the mechanism of carnitine recognition

Enomoto A、Wempe MF、Tsuchida H、Shin HJ、Cha SH、Anzai N、Goto A、Sakamoto A、Niwa T、Kanai Y、Anders MW、Endou H.：“人类睾丸特异性新型肉碱转运蛋白的分子鉴定：