Gating modes in AMPA receptors.
Gating modes in AMPA receptors.
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DOI：
10.1523/jneurosci.5613-09.2010
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发表时间：
2010-03-24
期刊：
影响因子：
--
通讯作者：
Wollmuth LP
中科院分区：
文献类型：
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作者：
Prieto ML;Wollmuth LP
AMPA受体是配体门控的离子通道，其显示多个电导水平，表明单个AMPA亚基的门控在一定程度上独立于其他亚基。为了研究AMPAR亚基在激活门控过程中的相互作用，我们在没有通道阻断和脱敏的情况下以及在负和正膜电位下从单通道记录。在饱和谷氨酸，相对occupancy的各种电导水平是一致的完全亚基的独立性。与此相反，在亚饱和谷氨酸的相对occupancy表明，通道之间的低开放概率模式和高开放概率模式，其中的通道的行为是相同的饱和谷氨酸的行为切换。这些门控模式在负电位和正电位下都发生，其中高开放概率模式在正电位下变得更加突出。门控模式之间的切换，以及电压和其他因素对其的调节可能构成了调节AMPAR介导的突触活动的新机制。
AMPA receptors are ligand-gated ion channels that show multiple conductance levels, indicating that gating of individual AMPA subunits is to some extent independent of other subunits. To study AMPAR subunit interactions during activation gating, we recorded from single channels in the absence of channel block and desensitization and at negative and positive membrane potentials. In saturating glutamate, the relative occupancies of the various conductance levels are consistent with complete subunit independence. In contrast, the relative occupancies in subsaturating glutamate indicate that the channel switches between a low open probability mode and a high open probability mode in which the behavior of the channel is identical to that in saturating glutamate. These gating modes occur at both negative and positive potentials, with the high open probability mode becoming more prominent at positive potentials. The switch between gating modes, and its modulation by voltage and other factors may constitute a novel mechanism regulating AMPAR-mediated synaptic activity.