CONDUCTING STATES OF A MAMMALIAN SEROTONIN TRANSPORTER
CONDUCTING STATES OF A MAMMALIAN SEROTONIN TRANSPORTER
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DOI：
10.1016/0896-6273(94)90337-9
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发表时间：
1994-04-01
期刊：
影响因子：
16.2
通讯作者：
LESTER, HA
中科院分区：
文献类型：
--
作者：
MAGER, S;MIN, C;LESTER, HA
我们已经研究了在克隆大鼠5-HT转运蛋白在非洲爪蟾卵母细胞中表达的渗透。[H-3]5-HT摄取和[I-125]RTI-55结合产生类似于1/s的周转率，其不依赖于膜电位。然而，在电压钳实验中，三个不同的电流结果从5-HT转运蛋白的表达。首先，5-HT应用诱导稳态的电压依赖性转运相关电流。第二，在没有5-HT的情况下，瞬时内向电流被电压跳变到高负电位激活，并被5-HT本身阻断。第三，在不存在5-HT的情况下观察到小的漏电流。所有观察到的电流被5-HT摄取抑制剂阻断，但受到Na+、Li+、K+、Ba ~（2+）、Cs+、Cl-和阿米洛利的不同影响。5-HT转运体的传导状态可能反映了类似于离子通道的渗透途径的存在。
We have studied permeation at a cloned rat 5-HT transporter expressed in Xenopus oocytes. [H-3]5-HT uptake and [I-125]RTI-55 binding yield a turnover rate of similar to 1/s that does not depend on membrane potential. However, in voltage-clamp experiments, three distinct currents result from 5-HT transporter expression. First, a steady-state, voltage-dependent transport-associated current is induced by 5-HT application. Second, a transient inward current is activated by voltage jumps to high negative potentials in the absence of 5-HT and is blocked by 5-HT itself. Third, a small leakage current is observed in the absence of 5-HT. All the observed currents are blocked by inhibitors of 5-HT uptake but are differentially affected by Na+, Li+, K+, Ba2+, Cs+, Cl-, and amiloride. The conducting states of the 5-HT transporter may reflect the existence of a permeation pathway similar to that of ionic channels.