Lenormand Guillaume, Chopin Julien, Bursac Predrag, Fredberg Jeffrey J, Butler James P
Molecular and Integrative Physiological Sciences, Department of Environmental Health, School of Public Health, Harvard University, Boston, MA 02115, USA.
Biochem Biophys Res Commun. 2007 Sep 7;360(4):797-801. doi: 10.1016/j.bbrc.2007.05.228. Epub 2007 Jul 5.
We report directional memory of spontaneous nanoscale displacements of an individual bead firmly anchored to the cytoskeleton of a living cell. A novel method of analysis shows that for shorter time intervals cytoskeletal displacements are antipersistent and thus provides direct evidence in a living cell of molecular trapping and caged dynamics. At longer time intervals displacements are persistent. The transition from antipersistence to persistence is indicative of a time-scale for cage rearrangements and is found to depend upon energy release due to ATP hydrolysis and proximity to a glass transition. Anomalous diffusion is known to imply memory, but we show here that memory is attributed to direction rather than step size. As such, these data are the first to provide a molecular-scale physical picture describing the cytoskeletal remodelling process and its rate of progression.
我们报告了牢固锚定在活细胞细胞骨架上的单个珠子自发纳米级位移的方向记忆。一种新的分析方法表明，在较短的时间间隔内，细胞骨架位移具有反持续性，从而在活细胞中为分子捕获和笼状动力学提供了直接证据。在较长的时间间隔内，位移是持续性的。从反持续性到持续性的转变表明了笼状重排的时间尺度，并且发现其取决于ATP水解导致的能量释放以及与玻璃化转变的接近程度。已知反常扩散意味着记忆，但我们在此表明，记忆归因于方向而非步长。因此，这些数据首次提供了描述细胞骨架重塑过程及其进展速率的分子尺度物理图景。
