Molecular mechanism of cytokinesis

胞质分裂的分子机制

基本信息

批准号：
02455009
负责人：
MABUCHI Issei
金额：
$ 4.54万
依托单位：
College of Arts and Sciences, University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02455009/
关键词：
Cytokinesis Cleavage furrow Cortractile ring Actin filament WGA receptor Protein phosphorylation Calyculin A Protein kinase ミオシンアクチン調節蛋白質

项目摘要

1)It has been considered that some signal is transfered from the mitotic apparatus to the cell cortex in order to form the contractile ring at a proper position. However, its mechanism has not been clarified yet. I investigated role of wheat germ agglutinin (WGA) receptors in this process, using fluorescein-labeled WGA. WGA receptors distributed on the surface of the egg during metaphase. They were aggregated into clusters during anaphase, which became fibrous in late anaphase. At telophase, they accumulated in the anticipated furrow region forming a ring. The distribution observed above was quite similar to that of actin filaments visualized by fluorescent phalloidin staining. It has been shown that the WGA receptors have intimate relationship to actin filament-anchoring sites on the plasma membrane. A possibility was denied that the receptors accumulate in the anticipated furrow region at first and then induce actin filament assembly. 2) When the unfertilized sea urchin eggs were incubated with calyculin A, a sponge toxin which inhibits activities of protein phopsphatases, cleavage was induced. Neither mitotic apparatus nor aster was formed in these eggs. Actin, myosin, and WGA receptors were accumulated in the furrow region. This process was inhibited by protein kinase inhibitors. It is suggested that protein phosphorylation is involved in the contractile ring formation. In addition, chromosomes were condensed and histone 1 kinase activity was increased in a cyclin Bindependent manner. 3) Last year, I reported isolation of cleavage furrows from Clypeaster japonicus eggs using a detergent-containing medium. I extended the isolation with Scaphechinus mirabilis eggs. I also isolated clevage furrows from eggs of Anthocidaris crassispina and Hemicentrotus pulcherrimus using modified medium. We found several proteins in 2-D gels common to these eggs and now determining partial peptide sequences.

1）人们认为，某些信号从有丝分裂设备转移到细胞皮层，以便在适当的位置形成收缩环。但是，其机制尚未澄清。我使用荧光素标记的WGA研究了小麦胚芽凝集素（WGA）受体的作用。 WGA受体分布在中期期间。它们在后期期间被聚集成簇，该簇在后期后期变成了纤维。在末期，它们积聚在形成环的预期犁沟区域中。上面观察到的分布与通过荧光鬼笔环肽染色可视化的肌动蛋白丝的分布非常相似。已经表明，WGA受体与质膜上的肌动蛋白丝生殖位点有着密切的关系。可能性否认受体首先积聚在预期的犁沟区域，然后诱导肌动蛋白丝组装。 2）当将未施用的海胆卵与钙蛋白A孵育时，抑制蛋白质磷酸酶活性的海绵毒素时，诱发了裂解。在这些卵中均未形成有丝分裂仪和紫色。肌动蛋白，肌球蛋白和WGA受体积聚在犁沟区域。蛋白激酶抑制剂抑制了此过程。建议蛋白质磷酸化参与收缩环形成。另外，染色体凝结，组蛋白1激酶活性以细胞周期蛋白结合方式增加。 3）去年，我报道了使用含洗涤剂的培养基中裂解裂解裂解的裂解。我用scaphechinus mirabilis卵扩大了隔离。我还使用改良培养基中的crassispina卵子和半肠杆菌的卵子中分离出裂缝沟。我们在这些卵共有的二维凝胶中发现了几种蛋白质，现在确定了部分肽序列。