Mechanism of the formation of contractile ring in dividing cultured animal cells. II. Cortical movement of microinjected actin filaments.
Mechanism of the formation of contractile ring in dividing cultured animal cells. II. Cortical movement of microinjected actin filaments.
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DOI：
10.1083/jcb.111.5.1905
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发表时间：
1990-11
期刊：
影响因子：
--
通讯作者：
Wang YL
中科院分区：
文献类型：
--
作者：
Cao LG;Wang YL
动物细胞分裂时的收缩环主要是通过现有肌动蛋白丝的重组而形成的。，和y - l。王》1990。J.细胞生物学。110:1089-1096)，但尚不清楚这一过程是否涉及细胞质中扩散肌动蛋白丝的随机募集，还是皮质相关丝向赤道方向的定向运动。我们通过观察肌动蛋白丝的分布来研究这个问题，这些肌动蛋白丝被荧光phalloidin标记并微注射到正常大鼠肾（NRK）细胞中。标记丝主要存在于中期前期和中期早期的细胞质中，但在后期开始前10-15分钟与细胞皮层广泛相关。这一过程既表现为皮层荧光强度的增加，也表现为肌动蛋白细丝的离散聚集体向皮层移动。后期开始后2-3 min，赤道区肌动蛋白荧光浓度检测，极地区荧光浓度下降。通过直接追踪标记肌动蛋白丝的聚集分布，我们能够检测到，在后期和末期，皮层肌动蛋白丝以平均1.0微米/分钟的速度向赤道移动。我们的结果，结合先前的观察，表明在细胞质分裂过程中肌动蛋白丝的组织可能涉及细胞质丝与皮层的关联，皮层丝向卵裂沟移动，以及丝与赤道皮层的分离。
The contractile ring in dividing animal cells is formed primarily through the reorganization of existing actin filaments (Cao, L.-G., and Y.-L. Wang. 1990. J. Cell Biol. 110:1089-1096), but it is not clear whether the process involves a random recruitment of diffusible actin filaments from the cytoplasm, or a directional movement of cortically associated filaments toward the equator. We have studied this question by observing the distribution of actin filaments that have been labeled with fluorescent phalloidin and microinjected into dividing normal rat kidney (NRK) cells. The labeled filaments are present primarily in the cytoplasm during prometaphase and early metaphase, but become associated extensively with the cell cortex 10-15 min before the onset of anaphase. This process is manifested both as an increase in cortical fluorescence intensity and as movements of discrete aggregates of actin filaments toward the cortex. The concentration of actin fluorescence in the equatorial region, accompanied by a decrease of fluorescence in polar regions, is detected 2-3 min after the onset of anaphase. By directly tracing the distribution of aggregates of labeled actin filaments, we are able to detect, during anaphase and telophase, movements of cortical actin filaments toward the equator at an average rate of 1.0 micron/min. Our results, combined with previous observations, suggest that the organization of actin filaments during cytokinesis probably involves an association of cytoplasmic filaments with the cortex, a movement of cortical filaments toward the cleavage furrow, and a dissociation of filaments from the equatorial cortex.