Monitoring transient Ca2+ dynamics with large-conductance Ca2+-dependent K+ channels at active zones in frog saccular hair cells.
Monitoring transient Ca2+ dynamics with large-conductance Ca2+-dependent K+ channels at active zones in frog saccular hair cells.
复制标题
利用大电导 Ca2 依赖性 K 通道监测青蛙囊毛细胞活性区的瞬态 Ca2 动态。
DOI：
10.1016/j.neuroscience.2009.11.003
复制
发表时间：
2010
期刊：
影响因子：
3.3
通讯作者：
Yazejian,B
中科院分区：
文献类型：
--
作者：
Sy,T;Grinnell,AD;Peskoff,A;Yazejian,B
听觉和前庭毛细胞基底外侧表面的神经递质释放是通过电压门控钙通道的钙内流来调节的。大电导钙激活的K+(BK)通道在这些细胞的活动区的共同定位为它们提供了一个最佳的位置来作为递质释放活动区的钙离子浓度变化的报告者。在本文中，我们利用蛙毛细胞的BK通道来监测瞬间钙内流过程中细胞内钙离子浓度的动态变化，结果表明BK电流的大小和延迟与通过钙通道进入细胞内钙的速率和持续时间有关。我们还发现，BK通道在开放状态下表现出比关闭状态下更高的钙结合亲和力。
Neurotransmitter release from the basolateral surface of auditory and vestibular hair cells is mediated by Ca2+influx through voltage-gated Ca2+channels. Co-localization of large-conductance Ca2+-activated K+(BK) channels at the active zones of these cells affords them with an optimal location to act as reporters of the Ca2+concentration changes at active zones of transmitter release. In this report we use BK channels in frog (Rana pipiens) hair cells to monitor dynamic changes in intracellular Ca2+concentration during transient influxes of Ca2+, showing that BK current magnitude and delay to onset are correlated with the rate and duration of Ca2+entry through Ca2+channels. We also show that BK channels exhibit a much higher Ca2+binding affinity in the open state than in the closed state.