Lehto Tiina, Miaczynska Marta, Zerial Marino, Müller Daniel J, Severin Fedor
BIOTEC, Technical University Dresden, 01609 Dresden, Germany.
FEBS Lett. 2003 Sep 11;551(1-3):25-8. doi: 10.1016/s0014-5793(03)00867-6.
High-resolution atomic force microscopy (AFM) was applied to directly observe the dynamic assembly of single actin filaments in HeLa cell extracts in vitro. The F-actin filaments established a dynamic network and formed different types of junctions and branches. The connections of this network were X-, Y- or T-shaped. It was found that the actin filaments were densely covered by endosomes and vesicles from the cell extract, which are thought to stabilize their structures. Using time-lapse AFM, the growth, shrinkage, branching and the interaction of actin filaments with endosomes could be characterized. Our results indicate that the majority of F-actin filaments are static in HeLa extract and that only a minor fraction of filaments undergo dynamic changes. Furthermore, the AFM imaging approach not only provides unique insights into the assembly and dynamics of actin networks; it also builds an avenue to study in vitro assays of complex biological systems.
高分辨率原子力显微镜（AFM）被用于直接观察体外HeLa细胞提取物中单个肌动蛋白丝的动态组装。F-肌动蛋白丝建立了一个动态网络，并形成了不同类型的连接和分支。这个网络的连接呈X形、Y形或T形。研究发现，肌动蛋白丝被细胞提取物中的内体和囊泡密集覆盖，这些内体和囊泡被认为可以稳定它们的结构。使用延时AFM，可以对肌动蛋白丝的生长、收缩、分支以及肌动蛋白丝与内体的相互作用进行表征。我们的结果表明，在HeLa提取物中，大多数F-肌动蛋白丝是静态的，只有一小部分肌动蛋白丝会发生动态变化。此外，AFM成像方法不仅为肌动蛋白网络的组装和动力学提供了独特的见解；它还为研究复杂生物系统的体外分析开辟了一条途径。
