Hierarchical Functional Construction of Cellular Motile Systems

细胞运动系统的分层功能构建

基本信息

批准号：
19207011
负责人：
ISHIWATA Shin'ichi
金额：
$ 33.36万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2007
资助国家：
日本
起止时间：
2007 至 2009
项目状态：
已结题

项目摘要

We focused on the examination of the effect of force on the activity of the molecular motors in a wide range of the hierarchical organization of the biological systems, from single molecules to assemblies of the motors and further on to the cells. Main achievements are summarized as follows : 1) The external forces were applied at various angles to the individual molecules of myosin V, processively moving on actin filaments in the presence of ATP, to test the robustness of the motor's motility under various loads. Furthermore, the mechanism ensuring high stability of the myosin V's motility under external loads was revealed by applying loads in various directions and measuring the unbinding forces of individual actin-myosin V complexes at different [ADP] (Oguchi et al., Nature Chem. Biol., 2010 ; for myosin VI, see Oguchi et al., PNAS, 2008). The main results of the unbinding force measurements on different motors, including myosins V and VI, as well as myosin II and kinesin, were summ … More arized and published (Mikhailenko et al., J. Royal Soc. Interface, 2010). 2) The response of individual sarcomeres in a single myofibril to the external mechanical stimulation under intermediate activation conditions revealed the coexistence of two types of sarcomeres : those responding to the application of load, and those remaining indifferent. These observations confirmed the existence of a mechanical inter-sarcomere coordination, helping us to establish the characteristic mechanism of muscle contraction and regulation (Shimamoto et el., PNAS, 2009). 3) We constructed the theoretic model explicitly describing the characteristics of contraction, including the auto-oscillation (SPOC), in a striated muscle (Sato et al., 2010, submitted). 4) We published the first report based on our research on vertebrate meiotic spindles self-assembled in Xenopus egg extracts, in which we tested their mechanical properties, such as deformability and stiffness, and the response to mechanical perturbations (Itabashi et al., Nature Methods, 2009). This work reported, inter alia, that the spontaneous re-assembly of spindles of different sizes can be induced by applying large controlled external loads. 5) To reveal the mechanisms underlying the stability of a characteristic "rugby ball"-like shape of the meiotic spindle, we quantitatively tested its response to mechanical stretch along the polar (long) axis, produced by the micromanipulation with a pair of microneedles. These measurements clearly demonstrated that a spindle responds to the large externally induced deformations, being able to preserve its shape via the modulation of polymerization/depolymerization of microtubules and the activity of kinesin and dynein molecular motors (MS in preparation). 6) We found that the local heating of HeLa cells using the ≧1 sec heat pulses, which increase the local temperature within cells by 0.1～few degrees centigrade, induces the oscillation of intracellular [Ca^<2+>]. Moreover, around 37℃ the cell responds to small, ～0.2℃, temperature changes, in which the IP_3 receptors were shown to be involved (Suzuki et al., HFSP J., 2009). Less

我们重点研究了力对生物系统各种层次组织中分子马达活动的影响，从单分子到马达组装，再到细胞。主要成就总结为：如下： 1) 以不同的角度对肌球蛋白 V 的各个分子施加外力，在 ATP 存在的情况下在肌动蛋白丝上持续移动，以测试电机在不同负载下运动的鲁棒性。通过在不同方向施加载荷并确保各个肌动蛋白-肌球蛋白 V 复合物在不同 [ADP] 下的解结合力，揭示了肌球蛋白 V 在外部载荷下运动的高稳定性（Oguchi 等人，Nature Chem. Biol.，2010；对于肌球蛋白 VI，参见 Oguchi 等人，PNAS，2008 对不同马达（包括肌球蛋白 V 和 VI）的解绑力测量的主要结果。肌球蛋白 II 和驱动蛋白，已总结并发表（Mikhailenko 等人，J. Royal Soc. Interface，2010）2）揭示了单个肌原纤维中单个肌节对中间激活条件下的外部机械刺激的反应。两种类型的肌节共存：对施加负载做出反应的肌节和保持中立的肌节这些观察结果证实了机械肌节间的存在。协调，帮助我们建立肌肉收缩和调节的特征机制（Shimamoto 等人，PNAS，2009）3）我们构建了明确描述收缩特征的理论模型，包括自动振荡（SPOC）。横纹肌（Sato et al.，2010，提交）4）我们发表了第一份基于爪蟾卵中自组装脊椎动物减数分裂纺锤体的研究报告。提取物，其中我们测试了它们的机械性能，例如变形性和刚度，以及对机械扰动的响应（Itabashi 等人，自然方法，2009）。这项工作除其他外，报告了纺锤体的自发重组。 5）为了揭示减数分裂纺锤体特征性“橄榄球”状形状稳定性的机制，我们定量测试了其对机械拉伸的响应。沿着极（长）轴，通过一对微针的显微操作产生，这些测量清楚地表明纺锤体对外部引起的大变形做出响应，能够通过微管的聚合/解聚的调节来保持其形状。驱动蛋白和动力蛋白分子马达的活性（MS 准备中） 6) 我们发现使用 ≧1 秒热脉冲对 HeLa 细胞进行局部加热，这会增加。细胞内局部温度升高0.1～几摄氏度，引起细胞内[Ca^<2+>]的振荡，而且在37℃左右，细胞对约0.2℃的微小温度变化有反应，其中IP_3受体受到影响。表明参与其中（Suzuki et al., HFSP J., 2009）。

项目成果

期刊论文数量（101）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

ミオシンVのコンバータードメインにある疎水残基は分子内の方の伝達において重要である

肌球蛋白 V 转换器结构域中的疏水残基对于分子内通讯很重要

DOI：
发表时间：
2008
期刊：
影响因子：
0
作者：
吉本順一;他5名
通讯作者：
他5名

心筋の自励振動能 : アクチン・ミオシンモーター蛋白質の働き他22件

心肌自激振荡能力：肌动蛋白/肌球蛋白运动蛋白等22种的功能

DOI：
发表时间：
2008
期刊：
影响因子：
0
作者：
Satoshi Kimura;Yoshiho Ikeuchi;Tomoyuki Numata;Daigo Nakamura;Takashi Yokogawa;Kazuya Nishikawa;Takeshi Wada;Takeo Suzuki;Tsutomu Suzuki;石渡信一
通讯作者：
石渡信一

活性化レベルに依存する骨格筋自励振動現象の振舞い

骨骼肌自激振动现象的行为取决于激活水平