克隆和表征两个K +的内向整流钾离子通道(吉珥)1.1同系物从人类肾脏(Kir1.2和Kir1.3)。
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剥去我,πTM、烈性黑啤酒JH Slightom杰,李KS, Bienkowski乔丹
克隆和表征两个K +的内向整流钾离子通道(吉珥)1.1同系物从人类肾脏(Kir1.2和Kir1.3)。
生物化学杂志。1997年1月3;272 (1):586 - 93。
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8995301 (在PubMed]
- 文摘
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老鼠大脑内的DNA序列编码rectifier-10 K +通道从老鼠大脑RNA放大使用逆转录-聚合酶链反应和用于克隆人类的相同器官。低严格筛选人体肾脏cDNA图书馆和随后的DNA序列分析确定了两个相关的K +内向整流的互补、称为Kir1.2 Kir1.3,来源于不同的人类基因的转录。Kir1.2代表了人类同族体鼠BIRK-10序列,而Kir1.3是独特而所有可用的序列数据基地。的基因编码Kir1.2和Kir1.3映射到人类染色体1和21岁的分别。两个基因型显示组织表达分析时北方的屁股。Kir1.2只是大脑> >肾脏和检测中发现高水平的大脑区域检查。Kir1.3最容易检测到肺肾和胰腺也表达了>。预测的氨基酸序列比较分析Kir1.2和Kir1.3显示他们62%相同。最显著的区别这两种多肽是沃克共识绑定类型主题出现在Kir1.1和Kir1.2并不守恒Kir1.3序列。Kir1.2多肽的表达非洲爪蟾蜍卵母细胞导致的K +通道选择性合成展出一个内心整流电流电压关系,抑制了外部媒体+和c +。 Kir1.2 current amplitude was reduced by >85% when the pH was decreased from pH 7.4 to 5.9 using the membrane-permeant buffer acetate but was relatively unaffected when pH was similarly lowered using membrane-impermeant biphthalate. The inhibition by intracellular protons was voltage-independent with an IC50 of pH 6.2 and a Hill coefficient of 1.9, suggesting the cooperative binding of 2 protons to the intracellular face of the channel. In contrast, Kir1.3 expression in Xenopus oocytes was not detectable despite the fact that the cRNA efficiently directed the synthesis of a polypeptide of the expected Mr in an in vitro translation system. Co-expression of Kir1.3 with either Kir1.1 or Kir1.2 reduced currents resulting from expression of these inward-rectifier subunits alone, consistent with a dominant negative influence on Kir1.1 and Kir1.2 expression.