Liposome reconstitution and modulation of recombinant N-methyl-D-aspartate receptor channels by membrane stretch
Liposome reconstitution and modulation of recombinant N-methyl-D-aspartate receptor channels by membrane stretch
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DOI：
10.1073/pnas.0609649104
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发表时间：
2007-01-30
影响因子：
11.1
通讯作者：
Martinac, Boris
中科院分区：
文献类型：
--
作者：
Kloda, Anna;Lua, Linda;Martinac, Boris
在这项研究中，异聚体N-甲基-D-天冬氨酸（NMDA）受体通道的NR 1a和NR 2A亚基组成的表达，纯化，重组到脂质体中，并使用膜片钳技术进行表征。该蛋白质表现出预期的电生理曲线激活谷氨酸和甘氨酸和内部Mg 2+封锁。我们证明了传递到膜结合NMIDA受体通道的机械能可以直接由脂质双层中产生的张力施加。膜拉伸和花生四烯酸的应用增强了细胞内Mg 2+存在下通过NMIDA受体通道的电流。由机械或化学刺激与生理Mg 2+阻断通道引起的膜张力的相关性表明，如果NMDA受体复合物经历由动态靶向脂质微区、电压缩或细胞膜的化学修饰引起的双层厚度的局部变化，则可以改变突触传递。在人工双层中研究NMIDA受体通道的门控特性的能力应证明在结构-功能关系的进一步研究中是有用的，并有助于发现用于治疗谷氨酸介导的兴奋性毒性或镇痛疗法的新治疗剂。
In this study, the heteromeric N-methyl-D-aspartate (NMDA) receptor channels composed of NR1a and NR2A subunits were expressed, purified, reconstituted into liposomes, and characterized by using the patch clamp technique. The protein exhibited the expected electrophysiological profile of activation by glutamate and glycine and internal Mg2+ blockade. We demonstrated that the mechanical energy transmitted to membrane-bound NMIDA receptor channels can be exerted directly by tension developed in the lipid bilayer. Membrane stretch and application of arachidonic acid potentiated currents through NMIDA receptor channels in the presence of intracellular Mg2+. The correlation of membrane tension induced by either mechanical or chemical stimuli with the physiological Mg2+ block of the channel suggests that the synaptic transmission can be altered if NMDA receptor complexes experience local changes in bilayer thickness caused by dynamic targeting to lipid microdomains, electrocompression, or chemical modification of the cell membranes. The ability to study gating properties of NMIDA receptor channels in artificial bilayers should prove useful in further study of structure-function relationships and facilitate discoveries of new therapeutic agents for treatment of glutamate-mediated excitotoxicity or analgesic therapies.