Functional regulation of Na+‐dependent neutral amino acid transporter ASCT2 by S‐nitrosothiols and nitric oxide in Caco‐2 cells
Functional regulation of Na+‐dependent neutral amino acid transporter ASCT2 by S‐nitrosothiols and nitric oxide in Caco‐2 cells
复制标题
DOI：
10.1016/j.febslet.2005.03.065
复制
发表时间：
2005-04
期刊：
影响因子：
3.5
通讯作者：
T. Uchiyama;Yasuyuki Matsuda;Miyuki Wada;Satoru Takahashi;T. Fujita
中科院分区：
文献类型：
--
作者：
T. Uchiyama;Yasuyuki Matsuda;Miyuki Wada;Satoru Takahashi;T. Fujita
我们描述了人肠细胞系 Caco-2 中 Na+ 依赖性中性氨基酸转运蛋白 ASCT2 通过一氧化氮 (NO) 的调节机制。将 Caco-2 细胞暴露于 S-亚硝基硫醇，例如 S-亚硝基-N-乙酰基-dl-青霉胺 (SNAP) 和 S-亚硝基谷胱甘肽，以及 NO 供体 NOC12，浓度和时间依赖性增加 Na+ 依赖性丙氨酸摄取。动力学分析表明，SNAP 增加了 Caco-2 细胞中 Na+ 依赖性丙氨酸摄取的最大速度 (Vmax)，而不影响 Michaelis-Menten 常数 (Kt)。放线菌素 D 和放线菌酮部分消除了刺激作用。 SNAP 增加的 Na+ 依赖性丙氨酸吸收被 NO 清除剂、2-(4-羧基苯基)-4,4,5,5-四甲基咪唑啉-1-氧基 3-氧化物钠盐 (羧基-PTIO) 和 N-(二硫代羧基)肌氨酸二钠盐 (DTCS) 以及 NADPH 氧化酶抑制剂二亚苯基碘部分消除。 RT-PCR显示Caco-2细胞表达Na+依赖性中性氨基酸转运蛋白ASCT2，但不表达其他Na+依赖性中性氨基酸转运蛋白ATB0、+和B0AT1。这些结果表明，SNAP 对 ASCT2 的功能上调可能部分与通过从头合成增加转运蛋白密度有关。
We describe the regulation mechanisms of the Na+-dependent neutral amino acid transporter ASCT2 via nitric oxide (NO) in the human intestinal cell line, Caco-2. Exposure of Caco-2 cells to S-nitrosothiol, such as S-nitroso-N-acetyl-dl-penicillamine (SNAP) and S-nitrosoglutathione, and the NO-donor, NOC12, concentration- and time-dependently increased Na+-dependent alanine uptake. Kinetic analyses indicated that SNAP increases the maximal velocity (Vmax) of Na+-dependent alanine uptake in Caco-2 cells without affecting the Michaelis–Menten constant (Kt). The stimulatory effect was partially eliminated by actinomycin D and cycloheximide. Increased Na+-dependent alanine uptake by SNAP was partially abolished by the NO scavengers, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide sodium salt (carboxy-PTIO) and N-(dithiocarboxy)sarcosine disodium salts (DTCS), as well as the NADPH oxidase inhibitor, diphenyleneiodonium. RT-PCR revealed that Caco-2 cells expressed the Na+-dependent neutral amino acid transporter ASCT2, but not the other Na+-dependent neutral amino acid transporters ATB0,+and B0AT1. These results suggested that functional up-regulation of ASCT2 by SNAP might be partially associated with an increase in the density of transporter protein via de novo synthesis.