Clathrin is involved in organization of mitotic spindle and phragmoplast as well as in endocytosis in tobacco cell cultures
Clathrin is involved in organization of mitotic spindle and phragmoplast as well as in endocytosis in tobacco cell cultures
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DOI：
10.1007/s00709-006-0226-7
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发表时间：
2007-03-01
期刊：
影响因子：
2.9
通讯作者：
Shimmen, T.
中科院分区：
文献类型：
--
作者：
Tahara, H.;Yokota, E.;Shimmen, T.
我们先前利用一种针对多头绒泡菌myosin II重链的单克隆抗体，从长花百合萌发花粉中鉴定出一个175 kDa的多肽。在本研究中，在培养的烟草BY-2细胞中也发现了相应的多肽。氨基酸序列分析表明，175 kDa多肽为网格蛋白重链，而非肌球蛋白重链。BY-2细胞染色后，点状网格蛋白信号在间期遍布细胞质。在有丝分裂和细胞分裂过程中，网格蛋白开始在纺锤体和膜质体中积累，然后在细胞板中密集聚集。网格蛋白重链的c端区（其中存在轻链结合和三聚结构域）的表达会抑制内吞作用，并导致异常纺锤体、层质体和细胞板的形成，这可能是观察到的多核细胞的原因。这些数据有力地表明，网格蛋白密切参与纺锤体和膜质体的形成，以及内吞作用。
We previously identified a 175 kDa polypeptide in Lilium longiflorum germinating pollen using a monoclonal antibody raised against myosin II heavy chain from Physarum polycephalum. In the present study, the equivalent polypeptide was also found in cultured tobacco BY-2 cells. Analysis of the amino acid sequences revealed that the 175 kDa polypeptide is clathrin heavy chain and not myosin heavy chain. After staining of BY-2 cells, punctate clathrin signals were distributed throughout the cytoplasm at interphase. During mitosis and cytokinesis, clathrin began to accumulate in the spindle and the phragmoplast and then was intensely concentrated in the cell plate. Expression of the C-terminal region of clathrin heavy chain, in which light chain binding and trimerization domains reside, induced the suppression of endocytosis and the formation of an aberrant spindle, phragmoplast, and cell plate, the likely cause of the observed multinucleate cells. These data strongly suggest that clathrin is intimately involved in the formation of the spindle and phragmoplast, as well as in endocytosis.