DISTINCT BEHAVIOR OF CONNEXIN56 AND CONNEXIN46 GAP JUNCTIONAL CHANNELS CAN BE PREDICTED FROM THE BEHAVIOR OF THEIR HEMI-GAP-JUNCTIONAL CHANNELS
DISTINCT BEHAVIOR OF CONNEXIN56 AND CONNEXIN46 GAP JUNCTIONAL CHANNELS CAN BE PREDICTED FROM THE BEHAVIOR OF THEIR HEMI-GAP-JUNCTIONAL CHANNELS
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DOI：
10.1016/s0006-3495(95)80356-5
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发表时间：
1995-05-01
影响因子：
3.4
通讯作者：
BEYER, EC
中科院分区：
文献类型：
--
作者：
EBIHARA, L;BERTHOUD, VM;BEYER, EC
缝隙连接蛋白大鼠连接蛋白46 （Cx46）具有在非洲爪蟾卵母细胞非连接质膜上形成电压门控通道的不寻常能力（Paul et al., 1991; Ebihara and Steiner, 1993）。这些被认为是间隙连接半通道或连接子。爪蟾卵母细胞系统被用来表征一种密切相关的晶体间隙连接蛋白chicken connexin56 （Cx56）的功能特性（Rup et al., 1993），并将其与大鼠Cx46的功能特性进行对比。注射Cx56或Cx46 cRNA的单个卵母细胞产生了时间依赖性的向外电流，该电流在去极化时激活。Cx56和Cx46产生的电流在稳态电压依赖性和整流程度上存在差异。此外，连接蛋白crna在含有低浓度钙离子的外部溶液中诱导的非连接通道的电压依赖性特性可以很好地解释成对卵母细胞中Cx56和Cx46形成的细胞间通道的行为。这些结果表明，细胞间通道保留了半间隙连接通道的许多电压依赖特性。
The gap-junctional protein rat connexin46 (Cx46) has the unusual ability to form voltage-gated channels in the nonjunctional plasma membrane of Xenopus oocytes (Paul et al., 1991; Ebihara and Steiner, 1993). These have been suggested to be gap-junctional hemichannels or connexons. The Xenopus oocyte system was used to characterize the functional properties of a closely related lens gap-junctional protein, chicken connexin56 (Cx56) (Rup et al., 1993) and to contrast them to those of rat Cx46. Single oocytes injected with either Cx56 or Cx46 cRNA developed time-dependent, outward currents that activated on depolarization. The currents induced by Cx56 and Cx46 showed differences in steady-state voltage dependence and in their degree of rectification. Furthermore, the voltage-dependent properties of the nonjunctional channels induced by the connexin cRNAs in external solutions containing low concentrations of calcium ions could account remarkably well for the behavior of the intercellular channels formed by Cx56 and Cx46 in paired oocytes. These results suggest that many of the voltage-dependent properties of the hemi-gap-junctional channels are retained by the intercellular channels.