Department of Biology, Northeastern University, Boston, Massachusetts, USA.
Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
Cytoskeleton (Hoboken). 2020 Oct;77(10):379-398. doi: 10.1002/cm.21633. Epub 2020 Oct 8.
Actomyosin networks are organized in space, direction, size, and connectivity to produce coordinated contractions across cells. We use the C. elegans spermatheca, a tube composed of contractile myoepithelial cells, to study how actomyosin structures are organized. FLN-1/filamin is required for the formation and stabilization of a regular array of parallel, contractile, actomyosin fibers in this tissue. Loss of fln-1 results in the detachment of actin fibers from the basal surface, which then accumulate along the cell junctions and are stabilized by spectrin. In addition, actin and myosin are captured at the nucleus by the linker of nucleoskeleton and cytoskeleton complex (LINC) complex, where they form large foci. Nuclear positioning and morphology, distribution of the endoplasmic reticulum and the mitochondrial network are also disrupted. These results demonstrate that filamin is required to prevent large actin bundle formation and detachment, to prevent excess nuclear localization of actin and myosin, and to ensure correct positioning of organelles.
肌动球蛋白网络在空间、方向、大小和连接性上进行组织，以产生跨细胞的协调收缩。我们使用线虫的受精囊，一个由收缩性肌上皮细胞组成的管，来研究肌动球蛋白结构是如何组织的。FLN-1/细丝蛋白对于组织中规则排列的平行、收缩、肌动球蛋白纤维的形成和稳定是必需的。fln-1 的缺失导致肌动蛋白纤维从基底表面脱落，然后沿着细胞连接积累，并被 spectrin 稳定。此外，肌动蛋白和肌球蛋白被核骨架和细胞骨架连接复合体（LINC）复合物捕获在核内，在那里它们形成大焦点。核定位和形态、内质网和线粒体网络的分布也被打乱。这些结果表明，细丝蛋白对于防止大肌动球蛋白束的形成和脱离，防止肌动蛋白和肌球蛋白的过度核定位，以及确保细胞器的正确定位是必需的。
