Ishibashi K, Sasaki S, Uchida S, Imai T, Marumo F
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Biochem Biophys Res Commun. 1993 Apr 30;192(2):561-7. doi: 10.1006/bbrc.1993.1452.
A new chloride channel has recently been identified by expression cloning (Paulmichl, M., et al. Nature 356: 238). To date there is no information available on the distribution of this channel in mammalian tissues. We cloned rat homologue of this Cl channel and found 92% identity in deduced amino-acid sequence. We studied the tissue distribution of its mRNA and regulation by protein kinases. Its mRNA was expressed in all 17 bovine tissues we studied, most abundantly in the brain. In the kidney, it was expressed more in the medulla than cortex. Dehydration up to 5 days did not change its mRNA level in the rat kidney. Both phorbol myristate acetate (PMA) and forskolin down regulated its expression in MDCK cells, suggesting that both PKC and PKA modulated its expression. The physiological role of this chloride channel remains to be clarified.
最近通过表达克隆鉴定出一种新的氯离子通道（保尔米希尔，M.等人，《自然》356：238）。迄今为止，关于该通道在哺乳动物组织中的分布尚无可用信息。我们克隆了该氯离子通道的大鼠同源物，发现推导的氨基酸序列中有92%的同一性。我们研究了其mRNA的组织分布以及蛋白激酶对其的调节作用。其mRNA在我们研究的所有17种牛组织中均有表达，在脑中表达最为丰富。在肾脏中，其在髓质中的表达多于皮质。长达5天的脱水并未改变大鼠肾脏中其mRNA水平。佛波酯肉豆蔻酸酯乙酸盐（PMA）和福斯高林均下调其在MDCK细胞中的表达，表明蛋白激酶C（PKC）和蛋白激酶A（PKA）均调节其表达。该氯离子通道的生理作用仍有待阐明。
