CytoMorpho Lab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Grenoble-Alpes University/CEA/CNRS/INRA, Grenoble, France.
CytoMorpho Lab, Hôpital Saint Louis, Institut Universitaire d'Hématologie, Université Paris Diderot/CEA/INSERM, Paris, France.
Nat Mater. 2021 Mar;20(3):410-420. doi: 10.1038/s41563-020-00825-z. Epub 2020 Oct 19.
Contractile actomyosin networks are responsible for the production of intracellular forces. There is increasing evidence that bundles of actin filaments form interconnected and interconvertible structures with the rest of the network. In this study, we explored the mechanical impact of these interconnections on the production and distribution of traction forces throughout the cell. By using a combination of hydrogel micropatterning, traction force microscopy and laser photoablation, we measured the relaxation of traction forces in response to local photoablations. Our experimental results and modelling of the mechanical response of the network revealed that bundles were fully embedded along their entire length in a continuous and contractile network of cortical filaments. Moreover, the propagation of the contraction of these bundles throughout the entire cell was dependent on this embedding. In addition, these bundles appeared to originate from the alignment and coalescence of thin and unattached cortical actin filaments from the surrounding mesh.
收缩性肌动球蛋白网络负责产生细胞内力。越来越多的证据表明，肌动蛋白丝束与网络的其余部分形成相互连接和相互转换的结构。在这项研究中，我们探讨了这些连接对整个细胞中牵引力的产生和分布的力学影响。我们通过使用水凝胶微图案化、牵引力显微镜和激光光蚀的组合，测量了对局部光蚀的牵引力的弛豫。我们的实验结果和网络力学响应的建模表明，纤维束沿着其整个长度完全嵌入在一个连续的、收缩性的皮质丝网络中。此外，这些束在整个细胞中的收缩传播依赖于这种嵌入。此外，这些束似乎源自周围网格中薄的、未附着的皮质肌动蛋白丝的排列和融合。
