Endoplasmic reticulum retention of KCNQ2 potassium channel mutants following temperature elevation
Endoplasmic reticulum retention of KCNQ2 potassium channel mutants following temperature elevation
复制标题
温度升高后 KCNQ2 钾通道突变体的内质网滞留
DOI：
10.3233/bme-171647
复制
发表时间：
2017
影响因子：
1
通讯作者：
He Xiaohua
中科院分区：
文献类型：
--
作者：
yu fang;xu jian;xiao zheman;Peng biwen;He Xiaohua
背景：KCNQ2在神经元兴奋性的调节中起关键作用。与BFNC相关的KCNQ2通道R214W和Y284C突变可降低通道功能，导致神经元过度兴奋，促进癫痫发作。以前的研究表明，温度升高会导致KCNQ2表达上调。目的：本研究旨在探讨温度升高对神经元KCNQ2离子通道突变体的影响。方法：用活细胞共聚焦荧光显微镜和Western blotting检测不同温度下wt KCNQ2、R214W、Y284C和截短选择滤器突变体的蛋白表达。采用全细胞膜片钳记录温度对KCNQ2通道电生理活动的影响。结果：温度升高导致电压依赖性KCNQ2通道的激活意外增加，但也增加了KCNQ2蛋白的内质网(ER)保留率，BFNC突变体的ER保留率大于wt KCNQ2突变体。结论：热对KCNQ2通道的直接作用可能参与神经元的兴奋性调节，P环区是KCNQ2通道表达和转运的温度依赖性调控的关键区域。
BACKGROUND:.KCNQ2 plays a key role in the regulation of neuronal excitability. The R214W and Y284C mutants of KCNQ2 channels, which are associated with BFNC, can decrease channel function to cause neuronal hyperexcitability and promote seizures. Previous studies revealed that elevated temperature caused up-regulation of KCNQ2 expression..OBJECTIVE:.The present study sought to investigate the impact of temperature elevation on neuronal KCNQ2 ion channel mutants..METHODS:.Protein expression of wt KCNQ2 and the R214W, Y284C and truncated selective filter mutants at different temperatures was detected by live-cell confocal fluorescence microscopy and by Western blotting. Whole-cell patch clamp was performed to record the effect of temperature on the electrophysiological activity of KCNQ2 channels..RESULTS:.Temperature elevation caused an unexpected increase in voltage-dependent KCNQ2 channel activation but also increased the endoplasmic reticulum (ER) retention of KCNQ2 protein, and the ER retention was greater for mutants associated with BFNC than for wt KCNQ2. Temperature elevation did not increase the fluorescence intensity of cells transfected with a truncated selective filter mutant..CONCLUSIONS:.The direct effect of heat on KCNQ2 channels may be involved in excitability regulation of neurons, and the P-loop region is critical for temperature-dependent modulation of the expression and trafficking of KCNQ2 channels.