The nature of the globular-to fibrous-actin transition
The nature of the globular-to fibrous-actin transition
复制标题
DOI：
10.1038/nature07685
复制
发表时间：
2009-01-22
期刊：
影响因子：
64.8
通讯作者：
Narita, Akihiro
中科院分区：
文献类型：
--
作者：
Oda, Toshiro;Iwasa, Mitsusada;Narita, Akihiro
肌动蛋白通过由聚合和解聚驱动的动态过程（即球状 (G) 到纤维状 (F) 肌动蛋白转变）在细胞运动中发挥关键作用。尽管我们对基于肌动蛋白的细胞功能和调节 G 肌动蛋白向 F 肌动蛋白转变的分子的了解不断增长，但这种转变的结构方面仍然是个谜。我们使用从兔骨骼肌 F-肌动蛋白的定向溶胶获得的 X 射线纤维衍射强度创建了 F-肌动蛋白模型，径向方向为 3.3 A，沿赤道方向为 5.6 A。在这里，我们表明 G 肌动蛋白到 F 肌动蛋白构象转变是两个主要结构域的简单相对旋转约 20 度。由于结构域旋转，丝中的肌动蛋白分子是扁平的。扁平形式对于形成稳定的螺旋状 F-肌动蛋白至关重要。我们的 F-肌动蛋白结构模型为理解肌动蛋白聚合及其与肌动蛋白结合蛋白的分子相互作用提供了基础。
Actin plays crucial parts in cell motility through a dynamic process driven by polymerization and depolymerization, that is, the globular ( G) to fibrous ( F) actin transition. Although our knowledge about the actin- based cellular functions and the molecules that regulate the G- to F- actin transition is growing, the structural aspects of the transition remain enigmatic. We created a model of F- actin using X- ray fibre diffraction intensities obtained from well oriented sols of rabbit skeletal muscle F- actin to 3.3 A in the radial direction and 5.6 A along the equator. Here we show that the G- to F- actin conformational transition is a simple relative rotation of the two major domains by about 20 degrees. As a result of the domain rotation, the actin molecule in the filament is flat. The flat form is essential for the formation of stable, helical F- actin. Our F- actin structure model provides the basis for understanding actin polymerization as well as its molecular interactions with actin- binding proteins.