Fairman W A, Sonders M S, Murdoch G H, Amara S G
Howard Hughes Medical Institute, Oregon Health Sciences University, Portland, USA.
Nat Neurosci. 1998 Jun;1(2):105-13. doi: 10.1038/355.
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.
花生四烯酸可调节参与细胞信号传导的膜蛋白的电学和生化特性。在表达兴奋性氨基酸转运体EAAT4的非洲爪蟾卵母细胞中，生理相关浓度的花生四烯酸可使底物激活电流的幅度在-60 mV时增加约两倍。这种刺激并非归因于底物/离子共转运或配体门控氯离子电流（与该载体相关的主要电导）的调节。离子置换实验表明，花生四烯酸可刺激质子选择性电导。该效应不需要花生四烯酸的代谢，也不会被内源性卵母细胞离子交换器的抑制剂所阻断。这种质子电导扩展了与EAAT4相关的配体门控通道特性的复杂组合。
