Laboratory of Molecular Neurobiology and Biophysics, Howard Hughes Medical Institute, The Rockefeller University, New York, United States.
Institute of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Elife. 2019 Nov 1;8:e50403. doi: 10.7554/eLife.50403.
TRAAK is a membrane tension-activated K channel that has been associated through behavioral studies to mechanical nociception. We used specific monoclonal antibodies in mice to show that TRAAK is localized exclusively to nodes of Ranvier, the action potential propagating elements of myelinated nerve fibers. Approximately 80 percent of myelinated nerve fibers throughout the central and peripheral nervous system contain TRAAK in what is likely an all-nodes or no-nodes per axon fashion. TRAAK is not observed at the axon initial segment where action potentials are first generated. We used polyclonal antibodies, the TRAAK inhibitor RU2 and node clamp amplifiers to demonstrate the presence and functional properties of TRAAK in rat nerve fibers. TRAAK contributes to the 'leak' K current in mammalian nerve fiber conduction by hyperpolarizing the resting membrane potential, thereby increasing Na channel availability for action potential propagation. We speculate on why nodes of Ranvier contain a mechanosensitive K channel.
TRAAK 是一种膜张力激活的钾通道，通过行为研究与机械性伤害感受有关。我们在小鼠中使用特异性单克隆抗体表明，TRAAK 仅定位于郎飞结，郎飞结是有髓神经纤维动作电位传播的元件。大约 80%的中枢和周围神经系统的有髓神经纤维中含有 TRAAK，可能是每个轴突的全节点或无节点方式。TRAAK 不在动作电位首先产生的轴突起始段观察到。我们使用多克隆抗体、TRAAK 抑制剂 RU2 和节点钳位放大器来证明大鼠神经纤维中 TRAAK 的存在和功能特性。TRAAK 通过超极化静息膜电位使哺乳动物神经纤维传导中的“泄漏”K 电流增加，从而增加 Na 通道对动作电位传播的可用性。我们推测为什么郎飞结包含机械敏感性钾通道。
