Effects of [Ca2+]i and temperature on minK channels expressed in Xenopus oocytes

FEBS Letters

Busch, Andreas E.¹  Lang, Florian¹ 

[1] Physiologisches Institut I, Eberhard-Karl-Universität Tübingen, Gmelinstr. 5, 72076 Tübingen, Germany

关键词: Slow potassium channel;    MinK channel;    Xenopus oocyte;    Q10;    Temperature;   

DOI  :  10.1016/0014-5793(93)81715-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Slowly activating, voltage-dependent minK channels cloned from rat kidney were expressed in Xenopus oocytes. Increase in the bath temperature from 22 to 32°C resulted in a dramatic acceleration of minK channel activation. The extraordinarily high Q₁₀ of minK channel activation was voltage-dependent, being higher at more negative potentials (Q₁₀ at −20 mV: 7.02; at 20 mV: 4.0). While activation of minK channels was highly voltage-dependent at 22°C, voltage had only little effect on minK channel activation at 32°C. Increase in [Ca²⁺]_i, which has recently been shown to increase the maximal conductance g _max at room temperature, did not affect g _max at 32°C. However, increase of [Ca²⁺]_i caused acceleration of minK channel activation at both temperatures. The interaction of [Ca²⁺]_i and temperature on g _max and activation rate of minK channels described here is very similar to recent findings on Ca- and temperature-effects on the slowly activating potassium conductance I _Ks in guinea pig cardiac myocytes.

【 授权许可】

Unknown