Rapid hop diffusion of a G-protein-coupled receptor in the plasma membrane as revealed by single-molecule techniques
Rapid hop diffusion of a G-protein-coupled receptor in the plasma membrane as revealed by single-molecule techniques
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DOI：
10.1529/biophysj.104.048538
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发表时间：
2005-05-01
影响因子：
3.4
通讯作者：
Kusumi, A
中科院分区：
文献类型：
--
作者：
Suzuki, K;Ritchie, K;Kusumi, A
扩散的G蛋白偶联受体，μ阿片受体（μ OR），在质膜被跟踪的单荧光分子视频成像和高速单粒子跟踪。与先前的出版物不同，其中发现金标记的μ OR完全被限制在一个域内，而该域本身又经历非常缓慢的扩散，我们发现μ OR经历了在膜隔室上的快速跳跃扩散（在正常大鼠肾细胞系的情况下为210 nm和730 nm嵌套双室），它们可能由基于肌动蛋白的膜骨架“栅栏或围栏”及其相关的跨膜蛋白“栅栏”界定，其速率与转铁蛋白受体相当（平均分别每45和760 ms），表明栅栏和尖桩模型也可适用于G蛋白偶联受体。此外，我们发现，强约束的金标记的莫尔受体可以诱导的延长冰上预孵育的金探针与细胞，这表明在未来的单粒子跟踪实验中，应避免这一过程。基于密集的，长轨迹的μ OR获得高速单粒子跟踪，膜室并列和毗邻彼此可以被定义为由相当直的边界界定，符合参与肌动蛋白。膜区室化的悲哀。
Diffusion of a G-protein coupled receptor, mu-opioid receptor (mu OR), in the plasma membrane was tracked by single-fluorescent molecule video imaging and high-speed single-particle tracking. At variance with a previous publication, where gold-tagged mu OR was found to be totally confined within a domain, which in turn underwent very slow diffusion itself, we found that mu OR undergoes rapid hop diffusion over membrane compartments (210-nm and 730-nm nested double compartments in the case of normal rat kidney cell line), which are likely delimited by the actin-based membrane-skeleton "fence or corrals'' and its associated transmembrane protein "pickets'', at a rate comparable to that for transferrin receptor (every 45 and 760 ms on average, respectively), suggesting that the fence and picket models may also be applicable to G-protein coupled receptors. Further, we found that strong confinement of gold-labeled mOR could be induced by the prolonged on-ice preincubation of the gold probe with the cells, showing that this procedure should be avoided in future single-particle tracking experiments. Based on the dense, long trajectories of mu OR obtained by high-speed single-particle tracking, the membrane compartments apposed and adjoined to each other could be defined that are delimited by rather straight boundaries, consistent with the involvement of actin. laments in membrane compartmentalization.