Bond C T, Pessia M, Xia X M, Lagrutta A, Kavanaugh M P, Adelman J P
Vollum Institute, Oregon Health Sciences University, Portland 97201.
Recept Channels. 1994;2(3):183-91.
Five new members of the two-transmembrane domain potassium channel family have been identified from rat brain, heart and skeletal muscle. The channel mRNAs are differentially expressed and found in both the central nervous system and periphery. Expression of two of these channels in Xenopus oocytes gave rise to inwardly rectifying potassium currents which were voltage-dependently blocked by barium and cesium. Voltage command pulses negative to Ek evoked inward currents which rapidly reached a peak amplitude and relaxed to a steady-state level. The quantity of current relaxation differed in the two channels and was increased at more negative potentials. The degree of current rectification was also different for the two channels. The results demonstrate the existence of a large and widely expressed family of inward rectifier potassium channel subunits with distinct tissue distributions and functional properties.
从大鼠脑、心脏和骨骼肌中已鉴定出两个跨膜结构域钾通道家族的五个新成员。这些通道的mRNA存在差异表达，且在中枢神经系统和外周均有发现。其中两个通道在非洲爪蟾卵母细胞中的表达产生了内向整流钾电流，该电流受到钡和铯的电压依赖性阻断。向负于Ek的电压指令脉冲诱发内向电流，该电流迅速达到峰值幅度并松弛至稳态水平。两个通道中电流松弛的量不同，且在更负的电位下增加。两个通道的电流整流程度也不同。结果表明存在一个广泛表达的大的内向整流钾通道亚基家族，其具有不同的组织分布和功能特性。
