CALCIUM SENSITIVITY OF BK-TYPE K-CA CHANNELS DETERMINED BY A SEPARABLE DOMAIN
CALCIUM SENSITIVITY OF BK-TYPE K-CA CHANNELS DETERMINED BY A SEPARABLE DOMAIN
复制标题
DOI：
10.1016/0896-6273(94)90034-5
复制
发表时间：
1994-09-01
期刊：
影响因子：
16.2
通讯作者：
SALKOFF, L
中科院分区：
文献类型：
--
作者：
WEI, A;SOLARO, C;SALKOFF, L
来自小鼠（mSlo）和果蝇（dSlo）的高电导、Ca2+激活的（BK型）K+通道在其功能特性上不同，但共享类似于电压门控K+通道的保守核心和通过非保守接头附加到核心的尾部。我们已经发现，通道亚基是物理上可分为这两个保守的域，并确定这样的属性，如通道开放时间，电导，并可能，电压依赖性的核心，而尾部决定明显的Ca2+的敏感性。这两个域都是功能所必需的。我们通过利用mSlo和dSlo之间的功能差异来证明核心和尾部的不同作用。从mSlo和dSlo的核心和尾部的异源配对表明，单通道特性始终是核心物种的特征，但表观Ca2+敏感性根据尾部的物种向上或向下调整。因此，尾部与BK通道的Ca2+传感作用有关。
High conductance, Ca2+-activated (BK-type) K+ channels from mouse (mSlo) and Drosophila (dSlo) differ in their functional properties but share a conserved core resembling voltage-gated K+ channels and a tail appended to the core by a nonconserved linker. We have found that the channel subunit is physically divisible into these two conserved domains and that the core determines such properties as channel open time, conductance, and, probably, voltage dependence, whereas the tail determines apparent Ca2+ sensitivity. Both domains are required for function. We demonstrated the different roles of the core and tail by taking advantage of the functional differences between mSlo and dSlo. Heterologous pairing of cores and tails from mSlo and dSlo showed that single-channel properties were always characteristic of the core species, but that apparent Ca2+ sensitivity was adjusted up or down depending on the species of the tail. Thus, the tail is implicated in the Ca2+ sensing role of BK channels.