ACTIN BASED MOTILITY ON RETRACTION FIBERS IN MITOTIC PTK2 CELLS
ACTIN BASED MOTILITY ON RETRACTION FIBERS IN MITOTIC PTK2 CELLS
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DOI：
10.1002/cm.970220207
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发表时间：
1992-01-01
影响因子：
--
通讯作者：
MITCHISON, TJ
中科院分区：
文献类型：
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作者：
MITCHISON, TJ
当PtK 2细胞在有丝分裂中聚集时，它们在基质和细胞体之间留下附着的收缩纤维。鬼笔环肽染色和电子显微镜观察显示，收缩纤维及其与胞体接触的区域富含肌动蛋白丝。视频显微镜用于研究肌动蛋白依赖收缩纤维的运动过程。小的、相致密的结节在纤维上自发形成，并以3 μ m/分钟的速度移动到细胞体中。当它们移动时，它们的相密度逐渐增加。这种运动似乎与肌动蛋白依赖的向心运动有关，这是以前在片状伪足中研究过的。尽管它的一般性，这种运动的机制是未知的，和回缩纤维提出了一些特殊的优势，其研究。细胞松弛素治疗导致结节停止移动和溶解。停药会使他们改革并开始搬家。令人惊讶的是，细胞松弛素撤药后的运动往往是向外的，表明皮质极性的局部逆转。几分钟后，通过全局控制机制重新建立正确的极性。这些意见的机制和极性的肌动蛋白依赖运动的影响进行了讨论。
When PtK2 cells round up in mitosis they leave retraction fibers attached between the substrate and the cell body. Retraction fibers and the region where they meet the cell body are rich in actin filaments as judged by phalloidin staining and electron microscopy. Video microscopy was used to study actin dependent motile processes on retraction fibers. Small, phase-dense nodules form spontaneously on the fibers, and move in to the cell body at a rate of 3-mu-m/minute. As they move in they increase progressively in phase-density. This movement appears to be related to actin dependent centripetal movement which has been previously studied in lamellipodia. Despite its generality, the mechanism of such movement is unknown, and retraction fibers present some special advantages for its study. Cytochalasin treatment causes nodules to stop moving and dissolve. Withdrawal of the drug causes them to reform and start moving. Surprisingly, movement after cytochalasin withdrawal was often outward, indicating a local reversal of cortical polarity. After a few minutes correct polarity is reestablished by a global control mechanism. The implications of these observations for the mechanism and polarity of actin dependent motility is discussed.