Lowering the barriers to random walks on the cell surface.
Lowering the barriers to random walks on the cell surface.
复制标题
降低细胞表面随机游走的障碍。
DOI：
10.1016/s0006-3495(03)74860-7
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Edidin,Michael
中科院分区：
文献类型：
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作者：
Tang,Qing;Edidin,Michael
采用光漂白后荧光恢复（FRAP）和单粒子跟踪（SPT）技术比较了ⅰ类主要组织相容性复合体分子（MHC）在正常和α-谱蛋白缺陷小鼠红白血病（MEL）细胞中的扩散。由于细胞骨架网作为膜蛋白横向移动的屏障，我们预计α-谱蛋白缺陷MEL细胞中的膜蛋白扩散将与正常MEL细胞中的膜蛋白扩散有很大不同。在这种情况下，从FRAP或SPT分析中得出的扩散系数对于α-谱蛋白缺陷和正常MEL细胞是相似的，在三种不同的时间尺度上（几十秒、1 - 10秒和100ms）相差约2倍。SPT分析显示，大多数I类MHC分子的扩散局限于两种细胞类型。在正常MEL细胞上，密闭区平均对角线长度为330nm，平均停留时间为40s。α-谱蛋白缺失的MEL细胞，平均对角线长度为650nm，平均停留时间为45s。因此，与正常MEL细胞相比，细胞骨架突变的MEL细胞的横向扩散障碍更少，但这种差异在这里测量的尺度上并不强烈影响横向扩散。
We used fluorescence recovery after photobleaching (FRAP) and single particle tracking (SPT) techniques to compare diffusion of class I major histocompatibility complex molecules (MHC) on normal andα-spectrin-deficient murine erythroleukemia (MEL) cells. Because the cytoskeleton mesh acts as a barrier to lateral mobility of membrane proteins, we expected that diffusion of membrane proteins inα-spectrin-deficient MEL cells would differ greatly from that in normal MEL cells. In the event, diffusion coefficients derived from either FRAP or SPT analysis were similar forα-spectrin-deficient and normal MEL cells, differing by a factor of ∼2, on three different timescales: tens of seconds, 1–10s, and 100ms. SPT analysis showed that the diffusion of most class I MHC molecules was confined on both cell types. On the normal MEL cells, the mean diagonal length of the confined area was 330nm with a mean residency time of 40s. On theα-spectrin-deficient MEL cells, the mean diagonal length was 650nm with a mean residency time of 45s. Thus there are fewer barriers to lateral diffusion on cytoskeleton mutant MEL cells than on normal MEL cells, but this difference does not strongly affect lateral diffusion on the scales measured here.