FUNCTIONAL EXPRESSION AND SUBCELLULAR-LOCALIZATION OF AN ANION-EXCHANGER CLONED FROM CHOROID-PLEXUS
FUNCTIONAL EXPRESSION AND SUBCELLULAR-LOCALIZATION OF AN ANION-EXCHANGER CLONED FROM CHOROID-PLEXUS
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DOI：
10.1073/pnas.87.14.5278
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发表时间：
1990-07-01
影响因子：
11.1
通讯作者：
KOPITO, RR
中科院分区：
文献类型：
--
作者：
LINDSEY, AE;SCHNEIDER, K;KOPITO, RR
我们已经分离了编码AE2的大鼠脑内的cDNA克隆，AE2是红细胞阴离子交换器带3(AE1)的同源物。免疫细胞化学和原位杂交显示，在脑内，AE2的表达局限于脉络丛上皮基外侧膜。在COS-7细胞中表达小鼠AE2全长基因后，细胞内pH发生了依赖于氯和碳酸氢盐的变化，表明AE2是一种氯/碳酸氢交换体。阳离子置换研究表明，AE2介导的交换不依赖于细胞外钠。表达突变的大鼠AE2cDNA克隆的COS-7细胞对阳离子和阴离子替代的反应相同，该克隆缺乏胞浆NH2末端660个氨基酸。这些结果表明，该结构域在转运蛋白正确插入质膜或阴离子交换中都不起重要作用。
We have isolated rat brain cDNA clones encoding AE2, a homologue of the erythrocyte anion exchanger, band 3 (AE1). Immunocytochemistry and in situ hybridization reveal that, in brain, AE2 expression is restricted to the basolateral membrane of the choroid plexus epithelium. Expression of a full-length mouse AE2cDNA in COS-7 cells resulted in chloride- and bicarbonate-dependent alterations in intracellular pH, demonstrating that AE2 is a Cl/HCO3 exchanger. Cation replacement studies indicate that AE2-mediated exchange is independent of extracellular sodium. COS-7 cells expressing a mutant rat AE2 cDNA clone that lacks the cytoplasmic NH2-terminal 660 amino acids exhibit identical responses to cation and anion substitution. These results indicate that this domain does not play a significant role in either correct insertion of the transporter into the plasma membrane or anion exchange.