VOLTAGE-DEPENDENT GATING OF SINGLE GAP JUNCTION CHANNELS IN AN INSECT-CELL LINE
VOLTAGE-DEPENDENT GATING OF SINGLE GAP JUNCTION CHANNELS IN AN INSECT-CELL LINE
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DOI：
10.1016/s0006-3495(94)80521-1
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发表时间：
1994-08-01
影响因子：
3.4
通讯作者：
WEINGART, R
中科院分区：
文献类型：
--
作者：
BUKAUSKAS, FF;WEINGART, R
细胞对的从头形成被用来检查单个间隙连接通道的门控特性。将昆虫细胞系（克隆C6/36，来源于白纹伊蚊）的两个单独的细胞彼此推压以引起间隙连接通道的形成。采用双电压钳方法控制细胞间电压梯度（V-j）并测量细胞间电流（I-j）。在细胞接触后4.7分钟，通道活动的第一个迹象是明显的。30分钟后达到的稳态偶联显示电导为8.7 nS。通道的形成不涉及内部和细胞外空间之间的泄漏。新形成的通道的第一次打开是缓慢的（25-28 ms）。每个制备物通过仅具有一个可操作间隙连接通道的阶段。利用该时间段来检查单通道特性。我们发现，单通道表现出几个电导状态不同的电导伽马（j）：一个完全开放的状态（伽马（j）（主状态）），几个子状态（伽马（j）（子状态）），残留状态（伽马（j）（残留））和关闭状态（伽马（j）（关闭））。γ（j）（主态）为375 pS，γ（j）（残差）范围为30 - 90 pS。相邻子态之间的跃迁为γ（j）（主态）的1/7-1/4。V-j对gamma（j）（主状态）没有影响，但对gamma（j）（残差）有轻微影响。涉及gamma（j）（闭合）的I-j跃迁是慢的（15-60 ms），而不涉及gamma（j）（闭合）的I-j跃迁是快的（
De novo formation of cell pairs was used to examine the gating properties of single gap junction channels. Two separate cells of an insect cell line (clone C6/36, derived from the mosquito Aedes albopictus) were pushed against each other to provoke formation of gap junction channels. A dual voltage-clamp method was used to control the voltage gradient between the cells (V-j) and measure the intercellular current (I-j). The first sign of channel activity was apparent 4.7 min after cell contact. Steady-state coupling reached after 30 min revealed a conductance of 8.7 nS. Channel formation involved no leak between the intra- and extracellular space. The first opening of a newly formed channel was slow (25-28 ms). Each preparation passed through a phase with only one operational gap junction channel. This period was exploited to examine the single channel properties. We found that single channels exhibit several conductance states with different conductances gamma(j): a fully open state (gamma(j)(main state)), several substates (gamma(j)(substates)), a residual state (gamma(j)(residual)) and a closed state (gamma(j)(closed)). The gamma(j)(main state) was 375 pS, and gamma(j)(residual) ranged from 30 to 90 pS. The transitions between adjacent substates were 1/7-1/4 of gamma(j)(main state). V-j had no effect on gamma(j)(main state), but slightly affected gamma(j)(residual). The I-j transitions involving gamma(j)(closed) were slow (15-60 ms), whereas those not involving gamma(j)(closed) were fast (