Arachidonic acid elicits a substrate-gated proton current associated with the glutamate transporter EAAT4
Arachidonic acid elicits a substrate-gated proton current associated with the glutamate transporter EAAT4
复制标题
DOI：
10.1038/355
复制
发表时间：
1998-06-01
影响因子：
25
通讯作者：
Amara, SG
中科院分区：
文献类型：
--
作者：
Fairman, WA;Sonders, MS;Amara, SG
花生四烯酸调节参与细胞信号传导的膜蛋白的电学和生物化学性质。在表达兴奋性氨基酸转运蛋白EAAT 4的非洲爪蟾卵母细胞中，生理相关浓度的花生四烯酸在-60 mV下使底物激活电流的振幅增加约两倍。这种刺激是不可归因于任何基板/离子cotransfer或配体门控氯离子电流，与该载体相关的主要电导调制。离子取代实验揭示花生四烯酸刺激质子选择性电导。这种作用不需要花生四烯酸的代谢，也不被内源性卵母细胞离子交换剂的抑制剂阻断。这种质子电导扩展了与EAAT 4相关的配体门控通道特性的复杂组成部分。
Arachidonic acid modulates both electrical and biochemical properties of membrane proteins involved in cellular signaling. In Xenopus laevis oocytes expressing the excitatory amino acid transporter EAAT4, physiologically relevant concentrations of arachidonic acid increase the amplitude of the substrate-activated current by roughly twofold at -60 mV. This stimulation is not attributable to the modulation of either substrate/ion cotransport or the ligand-gated chloride current, the major conductance associated with this carrier. ion-substitution experiments reveal that arachidonic: acid stimulates a proton-selective conductance. The effect does not require metabolism of arachidonic acid and is not blocked by inhibitors of endogenous oocyte ion-exchangers. This proton conductance expands the complex repertoire of the ligand-gated channel properties associated with EAAT4.