New structure and function in plant K+ channels: KCO1, an outward rectifier with a steep Ca2+ dependency
New structure and function in plant K+ channels: KCO1, an outward rectifier with a steep Ca2+ dependency
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DOI：
10.1093/emboj/16.10.2565
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发表时间：
1997-05-15
期刊：
影响因子：
11.4
通讯作者：
MullerRober, B
中科院分区：
文献类型：
--
作者：
Czempinski, K;Zimmermann, S;MullerRober, B
钾离子通道具有一个共同的成孔结构域，具有重要的生理功能。本文报道了拟南芥（Arabidopsis thaliana）中第一个高等植物外向整流钾离子通道（KCO 1）的克隆和功能分析。KCO 1是近年来在人和酵母中发现的一类新的双孔钾通道，具有4个跨膜片段和串联的钙离子结合EF-手型结构。异源表达KCO 1杆状病毒感染的昆虫（草地贪夜蛾）细胞导致向外整流，K+-选择性电流引起的去极化电压脉冲在全细胞测量。KCO 1的激活强烈依赖于存在纳摩尔浓度的胞质游离Ca 2 + [Ca 2 +]（cyt）。当[Ca 2 +]（cyt）调节至
Potassium (K+) channels mediating important physiological functions are characterized by a common pore-forming (P) domain, We report the cloning and functional analysis of the first higher plant outward rectifying K+ channel (KCO1) from Arabidopsis thaliana. KCO1 belongs to a new class of 'two-pore' K+ channels recently described in human and yeast, KCO1 has four putative transmembrane segments and tandem calcium-binding EF-hand motifs. Heterologous expression of KCO1 in baculovirus-infected insect (Spadoptera frugiperda) cells resulted in outwardly rectifying, K+-selective currents elicited by depolarizing voltage pulses in whole-cell measurements. Activation of KCO1 was strongly dependent on the presence of nanomolar concentrations of cytosolic free Ca2+ [Ca2+](cyt). No K+ currents were detected when [Ca2+](cyt) was adjusted to