KCNE1亚基对Cav1.2电流的调节及门控机制  

The regulation and gating mechanism of Cav1.2 current by KCNE1 subunit

作　　者：柯俊[1] 苏颖 董颖[2] 李泱[2] 王晓萍[1] 李世峰[1] 龚峥[1] 陈锋[1] Ke Jun;Su Ying;Dong YIng;Li Yang;Wang Xiaoping;Li Shifeng;Gong Zheng;Chen Feng(Emergency Department,Fujian Provincial Hospital,Provincial College of Clinical Medicine,Fujian Medical University,Fujian Emergency Medical Center,Fujian Provincial Institute of Emergency Medicine,Fuzhou 350001,China;Cardiology Department,General Hospital of People's Liberation Army,Beijing 100853,China)

机构地区：[1]福建省立医院急诊内科福建医科大学省立临床医学院福建省急救中心福建省急诊医学研究所,福州350001 [2]解放军总医院心内科,北京100853

出　　处：《中华急诊医学杂志》2018年第12期1365-1369,共5页Chinese Journal of Emergency Medicine

基　　金：国家自然科学基金项目(81870249);福建省自然科学基金面上项目(2016J01431)。

摘　　要：目的探讨KCNE1对Cav1.2电流的调节及门控机制。方法采用瞬时转染的方法,将Cav1.2通道质粒单独或与KCNE1质粒共同转入HEK293细胞上,实验分Cav1.2组和Cav1.2+KCNE1组(每组取15个细胞),采用全细胞膜片钳技术记录Cav1.2电流和门控动力学。结果KCNE1与Cav1.2共同转染后,Cav1.2电流显著降低。在0mV时,Cav1.2峰电流密度从(-14.8±2.5)pA/pF降为(-7.5±1.6)pA/pF(n=15,P<0.01)。门控机制研究发现,KCNE1对Cav1.2电流的调节主要是使通道稳态失活曲线向更负的方向移动,进而加速失活;同时,也使通道失活后恢复减慢,失活时间常数延长,两方面共同作用导致电流密度的降低。结论KCNE1亚基可以通过改变Cav1.2通道稳态失活和失活后恢复过程降低其电流密度。Objective To explore the regulation and mechanism of Cav1.2current by KCNE1. Methods Transient transfection was used to transfer Cav1.2channel plasmids separately or together with KCNE1plasmids into HEK293 cells.The experiment was divided into 2groups (15cells in each group): Cav1.2group,Cav1.2+KCNE1group.The whole-cell patch clamp technique was used to record Cav1.2 current and gating dynamics.Results After co-transfection of KCNE1 with Cav1.2,Cav1.2 current decreased significantly.At 0mV,peak current density of Cav1.2was reduced from (-14.8±2.5)pA/pF to (-7.5±1.6)pA/pF (n=15,P<0.01).Based on the gate control mechanism,it is found that the regulation of Cav1.2current by KCNE1mainly makes the steady-state inactivation curve of the channel shifted to a more negative direction,thus accelerating the inactivation.Meanwhile,the recovery process of the channel after inactivation is slowed down and the recovery time constant was prolonged.Conclusions The KCNE1subunit can reduce the current density of Cav1.2by changing the channel inactivation and recovery process.

关 键 词：KCNEl亚基 Cav1.2亚基 HEK293细胞 膜片钳技术 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]