CONFINED LATERAL DIFFUSION OF MEMBRANE-RECEPTORS AS STUDIED BY SINGLE-PARTICLE TRACKING (NANOVID MICROSCOPY) - EFFECTS OF CALCIUM-INDUCED DIFFERENTIATION IN CULTURED EPITHELIAL-CELLS
CONFINED LATERAL DIFFUSION OF MEMBRANE-RECEPTORS AS STUDIED BY SINGLE-PARTICLE TRACKING (NANOVID MICROSCOPY) - EFFECTS OF CALCIUM-INDUCED DIFFERENTIATION IN CULTURED EPITHELIAL-CELLS
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DOI：
10.1016/s0006-3495(93)81253-0
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发表时间：
1993-11-01
影响因子：
3.4
通讯作者：
YAMAMOTO, M
中科院分区：
文献类型：
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作者：
KUSUMI, A;SAKO, Y;YAMAMOTO, M
使用单粒子跟踪（SPT; nanovid显微镜）和荧光光漂白恢复（FPR）研究了培养的小鼠角质形成细胞系质膜中E-钙粘蛋白、表皮生长因子受体和转铁蛋白受体的运动。在SPT技术中，受体分子标记有40 nm-φ胶体金颗粒，其运动之后，视频增强差分干涉对比显微镜在33 ms的时间分辨率和纳米级的空间精度。通过开发一种基于均方位移随时间变化的曲线的方法来分析通过SPT获得的受体分子的轨迹。观察到四种典型的运动类型：（a）静止模式，其中微观扩散系数小于4.6 × 10（-12）cm 2/s;（B）简单布朗扩散模式;（c）定向扩散模式，其中单向运动叠加在随机运动上;以及（d）受限扩散模式，其中粒子经历布朗扩散（微观扩散系数在4.6 × 10（-12）和1 × 10（-9）cm 2/s之间）被限制在有限的区域内，可能是通过膜相关的细胞骨架网络。通过SPT获得的这些数据与通过FPR获得的数据的比较表明，质膜被划分成许多小域300-600 nm的直径（0.04-0.24 mum 2的面积），其中受体分子被限制在3-30秒的时间尺度内，并且通过FPR观察到的长程扩散可以通过受体连续运动到相邻的隔室而发生。钙诱导的分化降低了细胞表面细胞-细胞接触区域外定向扩散和静止模式中分子百分比的总和（提议为结合到细胞骨架/膜骨架的E-钙粘蛋白的百分比），从大约60%降至8%（分别为低钙和高钙培养基）。
The movements of E-cadherin, epidermal growth factor receptor, and transferrin receptor in the plasma membrane of a cultured mouse keratinocyte cell line were studied using both single particle tracking (SPT; nanovid microscopy) and fluorescence photobleaching recovery (FPR). In the SPT technique, the receptor molecules are labeled with 40 nm-phi colloidal gold particles, and their movements are followed by video-enhanced differential interference contrast microscopy at a temporal resolution of 33 ms and at a nanometer-level spatial precision. The trajectories of the receptor molecules obtained by SPT were analyzed by developing a method that is based on the plot of the mean-square displacement against time. Four characteristic types of motion were observed: (a) stationary mode, in which the microscopic diffusion coefficient is less than 4.6 x 10(-12) cm2/s; (b) simple Brownian diffusion mode; (c) directed diffusion mode, in which unidirectional movements are superimposed on random motion; and (d) confined diffusion mode, in which particles undergoing Brownian diffusion (microscopic diffusion coefficient between 4.6 x 10(-12) and 1 x 10(-9) cm2/s) are confined within a limited area, probably by the membrane-associated cytoskeleton network. Comparison of these data obtained by SPT with those obtained by FPR suggests that the plasma membrane is compartmentalized into many small domains 300-600 nm in diameter (0.04-0.24 mum2 in area), in which receptor molecules are confined in the time scale of 3-30 s, and that the long-range diffusion observed by FPR can occur by successive movements of the receptors to adjacent compartments. Calcium-induced differentiation decreases the sum of the percentages of molecules in the directed diffusion and the stationary modes outside of the cell-cell contact regions on the cell surface (which is proposed to be the percentage of E-cadherin bound to the cytoskeleton/membrane-skeleton), from approximately 60% to 8% (low- and high-calcium mediums, respectively).