TREK-2 (K2P10.1) and TRESK (K2P18.1) are major background K+ channels in dorsal root ganglion neurons
TREK-2 (K2P10.1) and TRESK (K2P18.1) are major background K+ channels in dorsal root ganglion neurons
复制标题
DOI：
10.1152/ajpcell.00629.2005
复制
发表时间：
2006-07-01
影响因子：
5.5
通讯作者：
Kim, Donghee
中科院分区：
文献类型：
--
作者：
Kang, Dawon;Kim, Donghee
背根神经节（DRG）神经元表达许多双孔结构域K+（K-2 P）通道的mRNA，其表现为背景K+通道。为了识别DRG神经元中的功能性背景K+通道，我们研究了DRG神经元细胞体的细胞附着和由内而外的斑块的单通道开口的性质。我们发现了七种类型的K+通道，在150 mM KCl浴溶液中，单通道电导范围从14到120 pS。这些K+通道中有4个显示出与TRESK（14 pS）、TREK-1（112 pS）、TREK-2（50 pS）和TRAAK（73 pS）相似的生物物理和药理学特性，它们是K2 P通道家族的成员。无法确定其他三种K+通道的分子身份，因为它们显示出低通道活性，并且很少观察到。在四种K-2 P通道中，TRESK样（14 pS）K+通道在24 ℃时最活跃。在37 ℃时，50-pS（TREK-2样）通道最活跃，对静息K+电流的贡献最大（69%），其次是TRESK样14-pS（16%）、TREK-1样112-pS（12%）和TRAAK样73-pS（3%）通道。在DRG神经元中，通过RT-PCR分析判断，所有四个K2 P通道以及那些ASK-1和ASK-3的mRNA都表达。我们的结果表明，TREKs和TRESK共同贡献了37 ℃时DRG神经元背景K+电导的> 95%。由于TREK和TRESK是受体激动剂调节的靶点，因此它们可能在DRG神经元兴奋性的调节中发挥积极作用。
Dorsal root ganglion (DRG) neurons express mRNAs for many two-pore domain K+ (K-2P) channels that behave as background K+ channels. To identify functional background K+ channels in DRG neurons, we examined the properties of single-channel openings from cell-attached and inside-out patches from the cell bodies of DRG neurons. We found seven types of K+ channels, with single-channel conductance ranging from 14 to 120 pS in 150 mM KCl bath solution. Four of these K+ channels showed biophysical and pharmacological properties similar to TRESK (14 pS), TREK-1 (112 pS), TREK-2 (50 pS), and TRAAK (73 pS), which are members of the K2P channel family. The molecular identity of the three other K+ channels could not be determined, as they showed low channel activity and were observed infrequently. Of the four K-2P channels, the TRESK-like (14 pS) K+ channel was most active at 24 degrees C. At 37 degrees C, the 50-pS (TREK-2 like) channel was the most active and contributed the most (69%) to the resting K+ current, followed by the TRESK-like 14-pS (16%), TREK-1-like 112-pS (12%), and TRAAK-like 73-pS (3%) channels. In DRG neurons, mRNAs of all four K2P channels, as well as those of TASK-1 and TASK-3, were expressed, as judged by RT-PCR analysis. Our results show that TREKs and TRESK together contribute > 95% of the background K+ conductance of DRG neurons at 37 degrees C. As TREKs and TRESK are targets of modulation by receptor agonists, they are likely to play an active role in the regulation of excitability in DRG neurons.