Mechanism of formation of the contractile ring during cytokinesis

胞质分裂过程中收缩环的形成机制

• 批准号: 15207013
• 负责人: MABUCHI Issei
• 金额: $ 31.62万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15207013/
• 关键词: gene; enzyme; cell; tissue; signal transduction; protein; cytokinesis; actin; myosin; 酵母; 分裂シグナル; 低分子量Gタンパク質; Rho; アクチン調節タンパク質; gene; enzyme; cell; tissue; signal transduction; protein; cytokinesis; actin; myosin; 酵母; 分裂シグナル; 低分子量Gタンパク質; Rho; アクチン調節タンパク質

1)rho4 and rho5 genes of fission yeast was cloned. Rho4 regulates localization of F-actin patches and organization of microtubules, and thereby formation of cell wall and the septum. Localization of Rho4 is regulated by RhoGDI while activity of Rho4 is regulated by the RhoGAP Rga92)Sea urchin Cdc42 showed 87% homology to human Cdc42. It binds IQGAP and thus enhancesw actin polymerization. IQGAP localizes to the cleavage furrow during cytokinesis.3)It was established that the C-terminal 134 residues are necessary and sufficient for localization of Myo2 to the division site. This region contains Ser1444 which is phosphorylated during interphase but dephosphorylated during M-phase. This dephosphorylation enables Myo2 to target Mid1 which is transmitted from the nucleus to the equatorial cortex during G2.4)The Rho1GEFs Rgf1 and Rgf2 are localized to the growing ends of fission yeast cell during interphase, while to the septum region during mitosis and are involved in synthesis of cell wall … More and the septum. Rgf3 accumulates at the division site forming a ring during mitosis, and the ring contracts as cytokinesis progresses. Rgf3 is considered to control formation of both the contractile ring and the septum through activation of Rho1.5)We determined directionality of F-actins in the F-actin cables in fission yeast cells by decorating the F-actins using myosin S1. The barbed end of the F-actins in the interphase cables face the growing end of the cell during interphase. During mitosis, it reversed. We proposed a hypothesis that myosin V transports materials necessary for polarized growth of the cell to the cell ends during interphase, while transports those necessary for division to the division site during mitosis.6)Fission yeast actin-depolymerizing factor Adf1 is localized to the F-actin patches during interphase and to the contractile ring during mitosis and cytokinesis. Adf1 is involved in formation of the contractile ring through its F-actin-severing activity. Its binding to F-actin in the cell is competitive with the tropomyosin Cdc8. It was also found that Adf1 cooperates with myosin-II in formation of the contractile ring. We propose that Adf1 is necessary for formation and stability of the contractile ring. Less

1）克隆裂变酵母的Rho4和Rho5基因。 Rho4调节F-肌动蛋白斑块和微管的组织的定位，从而形成细胞壁和隔膜。 Rho4的定位受Rhogdi的调节，而Rho4的活性受Rhogap RGA92的调节）Sea Purchin cdc42与人类CDC42同源87％。它结合了IQGAP，从而增强了肌动蛋白聚合。 IQGAP定位于细胞动力学期间的裂解沟。3）确定C末端134残基是必需的，足以将Myo2定位到分裂位点。该区域含有Ser1444，该SER1444在相间期间被磷酸化，但在M期间被去磷酸化。这种去磷酸化使Myo2能够靶向MID1，该靶标在G2.4中从细胞核传播到模棱两可的皮层）Rho1GEFS RGF1和RGF2在相间的裂变酵母菌细胞的末端不断增长，而在Mitisosis过程中，在Mitisosis中，在Mitisosis中，在Mitisosis中，并参与了Cell of Cell of Cell壁的合成……更多。 RGF3在有丝分裂过程中形成环的分裂部位积聚，并且随着细胞力学的进展，环收缩。通过激活Rho1.5），RGF3被认为可以控制收缩环和隔膜的形成。相间电缆中F-肌动蛋白的铁丝网端在相间期间面对细胞的生长端。在有丝分裂期间，它逆转了。我们提出了一个假设，即肌球蛋白V传输了相间期间细胞极化到细胞末端所必需的材料，而在有丝分裂期间将分裂所必需的材料运输到分裂位点。6）6）裂变酵母肌动蛋白 - 脱皮因子ADF1被定位于相互之间的偶像和有害环和ciitosis和ciltokinesisis时，将其定位于F-肌动蛋白斑块。 ADF1通过其F-肌动蛋白的活性参与了收缩环的形成。它与细胞中F-肌动蛋白的结合与肌球蛋白CDC8具有竞争力。还发现，ADF1与肌球蛋白-II合作，形成了收缩环。我们建议ADF1对于收缩环的形成和稳定性是必需的。较少的