The pore properties of human nociceptor channel TRPA1 evaluated in single channel recordings
The pore properties of human nociceptor channel TRPA1 evaluated in single channel recordings
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DOI：
10.1016/j.bbamem.2010.12.024
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发表时间：
2011-04-01
影响因子：
3.4
通讯作者：
Ache, B. W.
中科院分区：
文献类型：
--
作者：
Bobkov, Y. V.;Corey, E. A.;Ache, B. W.
TRPA通道检测不同感觉模态的刺激，包括广谱的化学感觉刺激、与组织损伤和炎症相关的伤害性刺激、机械刺激和热刺激。尽管对这些通道的潜在调节剂、激动剂和拮抗剂的了解越来越多，但通道调节和激活的确切机制仍然大多是未知的或有争议的，并且广泛争论。关于天然和异源表达的TRPA通道的基本生物物理参数也知之甚少。在这里，我们使用传统的单通道由内而外和由外而外的补丁记录从人TRPA 1通道瞬时表达在人胚肾293 T细胞的通道，以表征的选择性的通道的无机一价/二价和有机一价阳离子的存在下烯丙基异硫氰酸酯（AITC）。我们显示hTRPA 1通道对无机阳离子的相对渗透性为：Ca 2（+）（5.1）> Ba 2+（3.5）> Mg 2+（2.8）> NH 4+（1.5）> Li+（1.2）> Na+（1.0）>= K+（0.98）>= Rb+（0.98）> Cs+（0.95）;对有机阳离子的相对渗透性为：Na+（1.0）>=二甲胺（0.99）>三甲胺（0.7）>四甲基铵（0.4）> N-甲基-D-葡糖胺（0.1）。通过AITC激活hTRPA 1通道似乎将通道募集到具有增加的对大有机阳离子的渗透性的构象状态。在这种状态下，通道的孔可以被表征为扩张了大约1-2.5埃。这些发现为TRPA 1通道的基本特性和功能提供了重要的见解，特别是人类TRPA 1通道。(C)2010 Elsevier B. V.保留所有权利。
TRPA channels detect stimuli of different sensory modalities, including a broad spectrum of chemosensory stimuli, noxious stimuli associated with tissue damage and inflammation, mechanical stimuli, and thermal stimuli. Despite a growing understanding of potential modulators, agonists, and antagonists for these channels, the exact mechanisms of channel regulation and activation remain mostly unknown or controversial and widely debated. Relatively little is also known about the basic biophysical parameters of both native and heterologously expressed TRPA channels. Here we use conventional single channel inside-out and outside-out patch recording from the human TRPA1 channel transiently expressed in human embryonic kidney 293T cells to characterize the selectivity of the channel for inorganic mono-/divalent and organic monovalent cations in the presence of allylisothiocyanate (AITC). We show the relative permeability of the hTRPA1 channel to inorganic cations to be:Ca2(+) (5.1) > Ba2+ (3.5) > Mg2+ (2.8) > NH4+(1.5) > Li+ (1.2) > Na+ (1.0) >= K+ (0.98) >= Rb+ (0.98) > Cs+ (0.95);and to organic cations:Na+(1.0)>= dimethylamine (0.99)> trimethylamine (0.7)> tetramethylammonium (0.4)> N-methyl-D-glucamine (0.1). Activation of the hTRPA1 channels by AITC appears to recruit the channels to a conformational state with an increased permeability to large organic cations. The pore of the channels in this state can be characterized as dilated by approximately 1-2.5 angstrom. These findings provide important insight into the basic fundamental properties and function of TRPA1 channels in general and human TRPA1 channel in particular. (C) 2010 Elsevier B.V. All rights reserved.