Functional interaction between Rho effector proteins

Rho 效应蛋白之间的功能相互作用

基本信息

批准号：
18590262
负责人：
ISHIZAKI Toshimasa
金额：
$ 2.5万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590262/
关键词：
Rho actin cytoskeleton mDia ROCK cytokinesis cell migration vasculogenesis 細胞接着胚発生

项目摘要

Directed cell migration requires cell polarization and adhesion turnover, in which the actin cytoskeleton and microtubules work critically. The Rho GTPases induce specific types of actin cytoskeleton and regulate microtubule dynamics. In migrating cells, Cdc42 regulates cell polarity and Rac works in membrane protrusion. However, the role of Rho in migration is little known. Rho acts on two major effectors, ROCK and mDia1, among which mDia1 produces straight actin filaments and aligns microtubules. We found that the Rho-mDia1 pathway regulates polarization and adhesion turnover by aligning microtubules and actin filaments and delivering Apc/Cdc42 and c-Src to their respective sites of action in rat C6 glioma cells.mDia proteins belong to the formin family proteins that catalyze actin nucleation and polymerization. Although formin family proteins of nonmammalian species such as Drosophila diaphanous are essential in cytokinesis, whether and how mDia proteins function in cytokinesis rema … More in unknown. To address this issue, we depleted each of the three mDia isoforms in NIH 3T3 cells by RNA interference. Depletion of mDia2 selectively increased the number of binucleate cells. mDia2 accumulates in the cleavage furrow during anaphase to telophase, and concentrates in the midbody at the end of cytokinesis. Depletion of mDia2 induced contraction at aberrant sites of dividing cells, where contractile ring components such as RhoA, myosin, anillin, and phosphorylated ERM accumulated. Treatment with blebbistatin suppressed abnormal contraction, corrected localization of the above components, and revealed that the amount of F-actin at the equatorial region during anaphase/telophase was significantly decreased with mDia2 RNAi. These results demonstrate that mDia2 is essential in mammalian cell cytokinesis and that mDia2-induced F-actin forms a scaffold for the contractile ring and maintains its position in the middle of a dividing cell.Furthermore, we are also analyzing the role of another Rho effector molecule, ROCK, in vasculogenesis during embryonic development. Less

定向细胞迁移需要细胞极化和粘合剂更新，其中肌动蛋白细胞骨架和微管批判性地工作。 Rho GTPases诱导特定类型的肌动蛋白细胞骨架并调节微管动力学。在迁移细胞中，CDC42调节细胞极性，RAC在膜突出中起作用。但是，Rho在迁移中的作用鲜为人知。 RHO作用于岩石和MDIA1的两个主要作用，其中MDIA1产生直肌动蛋白丝并对齐微管。我们发现，Rho-MDIA1途径通过对齐微管和肌动蛋白丝并将APC/CDC42和C-SRC传递到大鼠C6胶质瘤细胞中的作用部位，从而调节极化和粘合性转移。尽管非哺乳动物物种（如果蝇diaphanous）的formin家族蛋白在细胞因子中至关重要，但MDIA蛋白在细胞因子中的作用以及如何在未知的细胞因子中起作用。为了解决这个问题，我们通过RNA干扰消耗了NIH 3T3细胞中的三个MDIA同工型中的每一个。 MDIA2的耗竭有选择地增加了二元细胞的数量。 MDIA2在末变剂到末期期间的裂解沟中积聚，并在细胞因子结束时集中在中体中。 MDIA2的耗竭会在分裂细胞的异常部位诱导收缩，其中收缩环组分（如RhoA，肌球蛋白，anillin和磷酸化的ERM）积累了收缩。用玻璃纤维蛋白的治疗抑制了异常收缩，校正了上述成分的定位，并揭示了使用MDIA2 RNAI在后期/末期期间在同期/末期期间等效区域的F-肌动蛋白量显着降低。这些结果表明，MDIA2在哺乳动物的细胞因子中至关重要，MDIA2诱导的F-肌动蛋白形成了收缩环的脚手架，并在分裂细胞的中间保持其位置。Furthermore。我们还正在分析另一种Rho Rho效应分子的作用。较少的