Appearance of actin microfilament 'twin peaks' in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP-fimbrin
Appearance of actin microfilament 'twin peaks' in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP-fimbrin
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DOI：
10.1111/j.1365-313x.2005.02558.x
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发表时间：
2005-11-01
期刊：
影响因子：
7.2
通讯作者：
Hasezawa, S
中科院分区：
文献类型：
--
作者：
Sano, T;Higaki, T;Hasezawa, S
高等植物肌动蛋白细胞骨架在植物形态建成和维持各种细胞活动中起着至关重要的作用。在这项研究中，我们建立了一个烟草BY-2细胞系，稳定转化与GFP-fimmectin结合结构域（ABD）2构建，允许可视化的肌动蛋白微丝（MF）在活细胞。使用这种细胞系，指定BY-GF 11，我们进行了时间顺序观察MF动态细胞周期进程。详细的分析显示，在G（2）晚期出现了一条宽的MF带，分离形成一个对应于有丝分裂中所谓的肌动蛋白耗尽区（ADZ）的结构。在BY-GF 11中，有丝分裂时细胞皮层的MF结构似乎形成两条带，而不是ADZ。荧光强度的细胞皮质的测量表明MF分布，类似于两个高峰，因此，我们命名为MF的结构“双峰”（MFTP）。在胞质分裂时，细胞板正好形成在MFTP之间的山谷内，而这种细胞板的引导被肌动蛋白聚合抑制剂破坏的MFTP扭曲。这些结果表明，MFTP起源于G（2）期的宽MF带，并作为胞质分裂的标记。
The actin cytoskeleton of higher plants plays an essential role in plant morphogenesis and in maintaining various cellular activities. In this study we established a tobacco BY-2 cell line, stably transformed with a GFP-fimbrin actin-binding domain (ABD) 2 construct, that allows visualization of actin microfilaments (MFs) in living cells. Using this cell line, designated BY-GF11, we performed time-sequential observations of MF dynamics during cell-cycle progression. Detailed analyses revealed the appearance of a broad MF band in the late G(2) phase that separated to form a structure corresponding to the so-called actin-depleted zone (ADZ) in mitosis. In BY-GF11, the MF structure at the cell cortex in mitosis appeared to form two bands rather than the ADZ. Measurements of fluorescent intensities of the cell cortex indicated an MF distribution that resembled two peaks, and we therefore named the structure MF 'twin peaks' (MFTP). The cell plate formed exactly within the valley between the MFTP at cytokinesis, and this cell-plate guidance was distorted by disruption of the MFTP by an inhibitor of actin polymerization. These results suggest that the MFTP originates from the broad MF band in the G(2) phase and functions as a marker of cytokinesis.