Molecular mechanism of cutokinesis

细胞运动的分子机制

基本信息

批准号：
59490013
负责人：
MABUCHI Issei
金额：
$ 6.02万
依托单位：
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：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59490013/
关键词：
Cytokinesis Actin Actin-modulating Proteins 収縮環

项目摘要

The purpose of this research project has been to clarify the mechanism of cytokinesis at a molecular level. The first approach we used was to study the formation of the contractile ring. As a result, we found following seven actin-modulating proteins and characterized them. (1) 45K protein-actin complex which is able to modulate both the rate of polymerization of actin and the end-to-end interactions of actin filaments by binding to the barbed end of the actin filament. (2) Alpha-actinin which crosslinks actin filaments in the absence of calcium ions to form filament bundles. (3) 100K protein which severs actin filaments in the presence of calcium ions. (4) 250K protein which crosslinks actin filaments in a Ca-independent manner. (5) 20K protein-actin complex which has prpperties similar to the 45K protein-actin complex. This protein was thought to attach to the inner surface of the plasma membrane and link actin filaments to the membrane. (6) Spectrin which crosslinks actin fialments in a Ca-independent manner. (7) A Ca-binding 15K protein which inhibits the rate of actin polymerization as well as microtubule assembly. Among these proteins, alpha-actinin was labeled with a fluorescent reagent and microinjected into living egg and pursued its movement in the cell. It was concentrated in the cleavage furrow region at cytokinesis. Therefore, this protein may be relevant to cytokinesis.The second approach was to study the mechanism of contraction of the cleavage furrow using cleavage furrow isolated from newt egg. By using electron microscopy we demonstrated that the parallel actin filaments in the contractile arc were crosslinked by various actin-crosslinking proteins. We also demonstrated that the contraction could be induced in the isolated furrow in vitro and it was inhibited by actin inhibitors.

该研究项目的目的是阐明分子水平上细胞因子的机制。我们使用的第一种方法是研究收缩环的形成。结果，我们发现了七种肌动蛋白调节蛋白并将其表征的。（1）45K蛋白 - 肌动蛋白复合物，能够通过与肌动蛋白丝的刺尾端结合来调节肌动蛋白的聚合速率和肌动蛋白丝的端到端相互作用。（2）在没有钙离子的情况下交联肌动蛋白丝的α-肌动蛋白以形成细丝束。（3）100K蛋白在存在钙离子的情况下切断肌动蛋白丝。（4）250k蛋白，以CA独立的方式交联肌动蛋白丝。（5）具有类似于45K蛋白 - 肌动蛋白复合物的propperties的20K蛋白 - 肌动蛋白复合物。该蛋白被认为附着在质膜的内表面，并将肌动蛋白丝与膜联系起来。（6）以CA独立的方式交联肌动蛋白的光谱。（7）一种CA结合15K蛋白，可抑制肌动蛋白聚合的速率以及微管组装。在这些蛋白质中，将α-肌动蛋白标记为荧光试剂，并将其显微注射到活卵中，并在细胞中进行运动。它集中在细胞因子的裂解沟区。因此，该蛋白可能与细胞因子有关。第二种方法是使用从Newt Egg分离的裂解沟研究裂解沟的收缩机理。通过使用电子显微镜，我们证明了收缩弧中的平行肌动蛋白丝通过各种肌动蛋白 - 跨链接蛋白交联。我们还证明，在体外的分离沟中可以诱导收缩，并被肌动蛋白抑制剂抑制。