DYNAMICS OF MICROTUBULE DEPOLYMERIZATION IN MONOCYTES
DYNAMICS OF MICROTUBULE DEPOLYMERIZATION IN MONOCYTES
复制标题
DOI：
10.1083/jcb.102.6.2023
复制
发表时间：
1986-06-01
影响因子：
7.8
通讯作者：
SALMON, ED
中科院分区：
文献类型：
--
作者：
CASSIMERIS, LU;WADSWORTH, P;SALMON, ED
人单核细胞，其含有很少的间期微管（35.4. ±. 7.7），用于研究微管解聚的动力学。用高浓度的诺考达唑（10 μ g/ml）或暴露于低温（3 ℃）突然阻断稳态微管组装。C）。在组装后的不同时间，处理细胞用于抗微管蛋白免疫荧光显微镜检查。用连接到荧光显微镜的增强摄像机观察染色的细胞。通过在细胞中上下聚焦，从电视监视器上的图像中描绘出每个微管的整个长度。这些痕迹随后被数字化输入计算机。观察到所有微管都起源于中心体，对照细胞的平均长度为7.1 ± 1.5。2.7μ m（n = 957个微管）。在解聚过程中，总微管聚合物和每个细胞的微管数量迅速减少。相反，持续存在的微管的平均长度缓慢下降。总微管聚合物和每个细胞的微管数量的损失的半衰期均为约。诺考达唑处理的细胞为40 s。解聚过程中的限速步骤是引发分解的速率。一旦引发，解聚似乎是灾难性的。进一步的动力学分析揭示了两类微管：70%的微管群体是非常不稳定的，并引发解聚率约为。比少数持久微管快23倍。冷处理产生了类似的解聚特性，但引发速率较慢。在这两种情况下，有一个显着的同源性和异质性的人口之间的微管解聚的起始。
Human monocytes, which contain few interphase microtubules (35.4 .+-. 7.7), were used to study the dynamics of microtubule depolymerization. Steady-state microtubule assembly was abruptly blocked with either high concentrations of nocodazole (10 .mu.g/ml) or exposure to cold temperature (3.degree. C). At various times after inhibiton of assembly, cells were processed for anti-tubulin immunofluorescence microscopy. Stained cells were observed with an intensified video camera attached to the fluroescence microscope. A tracing of the entire length of each individual microtubule was made from the image on the television monitor by focusing up and down through the cell. The tracings were then digitized into a computer. All microtubules were seen to originate from the centrosome, with an average length in control cells of 7.1 .+-. 2.7 .mu.m (n = 957 microtubules). During depolymerization, the total microtubule polymer and the number of microtubules per cell decreased rapidly. In contrast, there was a slow decrease in the average length of the persisting microtubules. The half-time for both the loss of total microtubule polymer and microtubule number per cell was .apprx. 40 s for nocodazole-treated cells. The rate-limiting step in the depolymerization process was the rate of initiation of disassembly. Once initiated, depolymerization appeared catastrophic. Further kinetic analysis revealed two classes of microtubules: 70% of the microtubule population was very labile and initiated depolymerization at a rate .apprx. 23 times faster than a minor population of persistent microtubules. Cold treatment yielded qualitatively similar characteristics of depolymerization, but the initiation rates were slower. In both cases there was a significant asynchrony and heterogeneity in the initiation of depolymerization among the population of microtubules.