Structure and function of cytoskeleton in plant cells

植物细胞细胞骨架的结构和功能

• 批准号: 05044139
• 负责人: SHIMMEN Teruo
• 金额: $ 3.52万
• 依托单位: Himeji Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044139/
• 关键词: cytoskeleton; cytoplasmic streaming; myosin; actin; calcium; pollen tube Characeae; tissue cultured cell; 培養細胞

The present project aimed to elucidate the mechanism of cytoplasmic streaming and its regulation. In addition, we succeeded in find important facts concerned with reverse fountain streaming in root hair cells of Hydrocharis and the effect of okadaic acid on cytoplasmic streaming in pollen tubes.1.Mechanism of Ca^<2+> regulation of cytoplasmic streaming in pollen tubes.Before starting this project, we have succeeded in purifying myosin containing a heavy chain of 170 kD from pollen tubes of lily. We analyzed Calcium sensitivity of the myosin.In our previous study, we succeeded in inducing sliding movement of pollen tube organelles along characean actin cables. Based on the fact, we concluded that myosin is associated with the organelles and concerned with generation of motive force of cytoplasm streaming in pollen tubes. In addition, we found that the reconstituted, movement was inhibited by calcium, and speculated that pollen tube myosin has inhibitory calcium regulation mechanism. In … More the present study, we found that motility monitored with in vitro motility assay is inhibited by calcium of muM levels. In addition, we found that actin-activated ATPase of the myosin is also inhibited by calcium of similar concentrations. This is the first success in purifying myosin equipped with calcium sensitivity from plant cells. Since the calcium sensitivity of the myosin is lost by partial proteolysis, this system is a suitable system in elucidating the molecular mechanism of calcium regulation of plant myosin.2.Mechanism of reverse fountain streamingIn root hair cells, typical reverse fountain streaming is observed. We studied the effect of cytochalasin B and micaloride B on the velocity of cytoplasmic streaming and the transvacuolar strand. Cytochalasin inhibited the cytoplasmic streaming in dose-response manner. At 10 muM, cytoplasmic streaming was stopped completely. In parallel with inhibition of cytoplasmic streaming, the transvacuolar strands disappeared. When chtochalasin was removed, both the cytoplasmic streaming and the transvacuolar strand were recovered. Thus, effect of cytochalasin is reversible. Micaloride B also inhibited the cytoplasmic streaming and disrupted the transvacuolar strand. It was discussed that use of cytochalasin and micaloride in combination is a powerful tool in studying structure and function of cytoskeleton in plant cells.3.Effect of okadaic acid on cytoplasmic streaming and actin filamentEffect of specific inhibitor of protein phosphatase was studied with special reference to cytoplasmic streaming and actin filaments in lily pollen tube. It was found that okadaic acid inhibited without disrupting actin filaments, supporting that okadaic acid inhibit the activity of myosin via inhibition of dephosphorylation. Less

本项目旨在阐明细胞质流的机理及其调节。 In addition, we succeeded in find important facts concerned with reverse fountain streaming in root hair cells of Hydrocharis and the effect of okadaic acid on cytoplasmic streaming in pollen tubes.1.Mechanism of Ca^<2+> regulation of cytoplasmic streaming in pollen tubes.Before starting this project, we have succeeded in purifying myosin containing a heavy chain of 170 kD from pollen tubes of莉莉。我们分析了肌球蛋白的钙敏感性。在先前的研究中，我们成功地诱导了沿特征肌动蛋白电缆的花粉管细胞器的滑动运动。基于这一事实，我们得出的结论是，肌球蛋白与细胞器有关，并且与花粉管中细胞质流的动力产生有关。此外，我们发现重构，运动受到钙的抑制，并推测花粉管肌球蛋白具有抑制性钙调节机制。在……更多的本研究中，我们发现通过妈妈水平的钙抑制了通过体外运动评估监测的运动性。此外，我们发现肌动蛋白的肌动蛋白激活的ATPase也通过相似浓度的钙抑制。这是纯化肌球蛋白配备了植物细胞钙敏感性的第一个成功。由于肌球蛋白的钙敏感性因部分蛋白水解而丧失，因此该系统是阐明植物肌球蛋白钙调节的分子机理的合适系统。2。反向喷泉式流膜根毛细胞的力学，典型的反向喷泉流了。我们研究了细胞切拉蛋白B和Micaloride B对细胞质流速度和透术链的速度的影响。细胞切拉斯蛋白以剂量反应方式抑制细胞质流。在10妈妈时，细胞质流完全停止。与细胞质流的抑制并行，转换链消失了。当去除chtochalasin时，恢复了细胞质流和经障碍链。恢复了细胞质流和经障碍链的影响。 Micaloride B还抑制了细胞质流并破坏了Transvacuolar链。 It was discussed that use of cytoplasmic streaming and micaloride in combination is a powerful tool in studying structure and function of cytoskeleton in plant cells.3.Effect of okadaic acid on cytoplasmic streaming and actin filamentEffect of specific inhibitor of protein phosphatase was studied with special reference to cytoplasmic streaming and actin filaments in lily pollen tube.发现冈田酸会抑制而不会破坏肌动蛋白丝，从而支持冈田酸通过抑制去磷酸抑制肌球蛋白的活性。较少的

项目成果

Yokota,E.,Mabuchi,I.: "Isolation and characterization of a novel dynein that contains C and A heavy chains from sea urchin spermflagellar axonemes." J.Cell Sci.(印刷中).

Yokota, E., Mabuchi, I.：“含有来自海胆精鞭毛轴丝的 C 和 A 重链的新型动力蛋白的分离和表征。”J. Cell Sci。

Yokota,E. and Mabuchi,I.: "Isolation and characterization of a novel dynein that contains C and A heavy chains from sea urchin sperm flagellar axonemes." J. Cell Science. (in press).

横田，E.

Beilby.M.J.,Mimura.T.,Shimmen,T.: "The proton pump, high pH channels, and excitation: voltage clamp studies of intact and perfused cells of Nitellopsis obtusa" Protoplasma. 175. 144-152 (1993)

Beilby.M.J.、Mimura.T.、Shimmen,T.：“质子泵、高 pH 通道和激发：完整和灌注 Nitellopsis obtusa 细胞的电压钳研究”原生质体。

Shimmen,T.: Iwanami Shoten (in Japanese). Biology of the Cell, 1-180 (1993)

Shimmen,T.：岩波商店（日语）。