CENTRIPETAL TRANSPORT OF MICROTUBULES IN MOTILE CELLS
CENTRIPETAL TRANSPORT OF MICROTUBULES IN MOTILE CELLS
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DOI：
10.1002/cm.970320303
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发表时间：
1995-01-01
影响因子：
--
通讯作者：
GUNDERSEN, GG
中科院分区：
文献类型：
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作者：
MIKHAILOV, AV;GUNDERSEN, GG
细胞中微管（MT）动力学的研究在很大程度上局限于在培养的非运动或静止细胞中相对短时间内发生的事件。通过使用抗氧化剂氧化酶，我们降低了荧光mt对光损伤的敏感性，这使我们能够在更长的时间内以良好的时间分辨率对荧光mt进行成像。我们使用我们增强的成像能力来检查成纤维细胞定向进入伤口的MT动力学。我们发现这些细胞中的mt表现出与其他细胞相似的动态不稳定性。更有趣的是，我们发现了mt的一种新的动态行为，即整个mt从前沿向细胞核内移动。这种向心输运（CT）只发生在长轴平行于前缘的mtts上；径向取向的mt不向心输送。观察到小束mt和单个mt均以0.63 +/- 0.37 μ m/min的速率进行CT扫描。这一速率与应用于细胞表面的乳胶珠和细胞质中内源性胞饮囊泡的CT速率相似。当我们对mt和胞饮性囊泡进行成像时，我们发现胞饮性囊泡被一小群平行的mt包裹着，这些mt与囊泡一起向心移动。相反，我们发现许多mt向心运动的例子没有相关的囊泡。当细胞用诺可唑快速解聚MTs时，胞浆性囊泡CT率被抑制75%。这表明MTs的向心转运可能参与了细胞内胞饮囊泡的运动。总之，我们的研究结果表明，运动细胞中的mt通过一种新的机制CT重新分布，而这种机制不需要改变聚合物的长度。向心转运的mt可能在细胞内转运胞饮囊泡中起作用。(C) 1995 Wiley-Liss, Inc。
The study of microtubule (MT) dynamics in cells has largely been restricted to events occurring over relatively short periods in nonmotile or stationary cells in culture. By using the antioxidant, Oxyrase, we have reduced the sensitivity of fluorescent MTs to photodamage and this has allowed us to image fluorescent MTs with good temporal resolution over much longer periods of time. We have used our enhanced imaging capabilities to examine MT dynamics in fibroblasts moving directionally into a wound. We found that MTs in these cells exhibited dynamic instability similar to that reported for other cells. More interestingly, we found a novel dynamic behavior of the MTs in which entire MTs were moved inward from the leading edge toward the cell nucleus. This centripetal transport (CT) of MTs only occurred to those MTs that were oriented with their long axis parallel to the leading edge; radially oriented MTs were not transported centripetally. Both small bundles of MTs and individual MTs were observed to undergo CT at a rate of 0.63 +/- 0.37 mu m/min. This rate was similar to the rate of CT of latex beads applied to the cell surface and of endogenous pinocytotic vesicles in the cytoplasm. When we imaged both MTs and pinocytotic vesicles, we found that the pinocytotic vesicles were ensheathed by a small group of parallel MTs that moved centripetally in concert with the vesicles. Conversely, we found many instances of MTs moving centripetally without associated vesicles. When cells were treated with nocodazole to depolymerize MTs rapidly, the rate of pinocytotic vesicle CT was inhibited by 75%. This suggests that centripetal transport of MTs may be involved in the movement of pinocytotic vesicles in cells. In conclusion, our results show that MTs in motile cells are redistributed by a novel mechanism, CT, that does not require changes in polymer length. The centripetally transported MTs may play a role in transporting pinocytotic vesicles in the cell. (C) 1995 Wiley-Liss, Inc.