Blair T A, Roberds S L, Tamkun M M, Hartshorne R P
Department of Pharmacology, Oregon Health Sciences University, Portland 97201.
FEBS Lett. 1991 Dec 16;295(1-3):211-3. doi: 10.1016/0014-5793(91)81420-d.
A voltage-sensitive K+ channel previously cloned from rat heart designated RK5 (rat Kv4.2) (Roberds and Tamkun, 1991, Proc. Natl. Acad. Sci. USA 88, 1798-1802) was functionally characterized in the Xenopus oocyte expression system. RK5 is a homolog of the Drosophila Shal K+ channel, activates with a rise time of 2.8 ms, has a midpoint for activation of -1 mV and rapidly inactivates with time constants of 15 and 60 ms. RK5 is sensitive to 4-AP, IC50 = 5 mM, and is insensitive to TEA and dendrotoxins. The voltage dependence and kinetics of the RK5 induced currents suggest this channel contributes to the Ito current in heart.
一种先前从大鼠心脏克隆出来的电压敏感性钾通道，命名为RK5（大鼠Kv4.2）（罗伯兹和坦昆，1991年，《美国国家科学院院刊》88卷，1798 - 1802页），在非洲爪蟾卵母细胞表达系统中进行了功能特性研究。RK5是果蝇Shal钾通道的同源物，激活上升时间为2.8毫秒，激活中点为 -1毫伏，并且以15和60毫秒的时间常数快速失活。RK5对4 - 氨基吡啶（4 - AP）敏感，半数抑制浓度（IC50） = 5毫摩尔，对四乙铵（TEA）和树眼镜蛇毒素不敏感。RK5诱导电流的电压依赖性和动力学表明该通道对心脏中的Ito电流有贡献。
