Grigoriev I S, Chernobelskaya A A, Vorobjev I A
Belozersky Institute of Physico-Chemical Biology, Moscow State University.
Membr Cell Biol. 1997;11(2):195-211.
Movements of cytoplasmic organelles were analyzed in Vero fibroblasts. In the cells polarized at the edge of an experimental wound, cytoplasmic granules moved randomly (Brownian motions) and by separate jumps (saltatory movements). The displacement of granules by the Brownian motions exceeded by more than an order of magnitude that of the mitochondria similar by weight. Lipid droplets moved predominantly by saltations, whereas mitochondria and lysosomes moved much less often. In a front part of the polarized cells, the main directions of saltatory movements were from the nucleus to the leading edge of a cell and back, whereas the tangential movements (across the long axis of a cell) were less than 1%. 90% of saltatory movements occurred in the area starting 10-12 microm from the nucleus and ending 10-12 microm from the leading edge of a cell. The average rate of saltatory movements of the granules (2.38 microm/s) was identical in both directions. The average length of the track was 7.49 microm; the maximum track length reached 30 microm. An increase in the granule diameter from 0.3 to 1.4 microm resulted in a minor (statistically insignificant) decrease in the average rate of the movements. The average rate of saltatory movements of mitochondria was 1.00 microm/s, and the average track length was 6.04 microm. Therefore, mitochondria, in contrast to lipid droplets, are rigidly fixed in the cytoplasm, and the force holding mitochondria is equal to the force produced by the microtubule-associated motors. Taking into account the characteristic of the centrifugal saltations, we suggest that they are mediated by an unusual dynein.
在Vero成纤维细胞中分析了细胞质细胞器的运动。在实验伤口边缘极化的细胞中，细胞质颗粒随机移动（布朗运动）并通过单独的跳跃（跳跃运动）移动。布朗运动导致的颗粒位移比重量相似的线粒体的位移超过一个数量级。脂滴主要通过跳跃移动，而线粒体和溶酶体移动的频率要低得多。在极化细胞的前部，跳跃运动的主要方向是从细胞核到细胞的前缘再返回，而切向运动（跨细胞长轴）小于1%。90%的跳跃运动发生在从细胞核开始10 - 12微米到细胞前缘结束10 - 12微米的区域。颗粒跳跃运动的平均速率（2.38微米/秒）在两个方向上是相同的。轨迹的平均长度为7.49微米；最大轨迹长度达到30微米。颗粒直径从0.3微米增加到1.4微米导致运动平均速率略有下降（统计学上不显著）。线粒体跳跃运动的平均速率为1.00微米/秒,平均轨迹长度为6.04微米。因此，与脂滴不同，线粒体在细胞质中被牢固固定，固定线粒体的力等于微管相关马达产生的力。考虑到离心跳跃的特征，我们认为它们是由一种不寻常的动力蛋白介导的。
