Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
J Cell Biol. 2018 Mar 5;217(3):1033-1045. doi: 10.1083/jcb.201705104. Epub 2018 Jan 11.
Growth of epithelial tissues is regulated by a plethora of components, including signaling and scaffolding proteins, but also by junctional tension, mediated by the actomyosin cytoskeleton. However, how these players are spatially organized and functionally coordinated is not well understood. Here, we identify the scaffolding protein Big bang as a novel regulator of growth in epithelial cells of the wing disc by ensuring proper junctional tension. Loss of results in the reduction of the regulatory light chain of nonmuscle myosin, Spaghetti squash. This is associated with an increased apical cell surface, decreased junctional tension, and smaller wings. Strikingly, these phenotypic traits of mutant discs can be rescued by expressing constitutively active Spaghetti squash. Big bang colocalizes with Spaghetti squash in the apical cytocortex and is found in the same protein complex. These results suggest that in epithelial cells of developing wings, the scaffolding protein Big bang controls apical cytocortex organization, which is important for regulating cell shape and tissue growth.
上皮组织的生长受多种成分的调节，包括信号和支架蛋白，还受细胞骨架肌动球蛋白介导的连接张力调节。然而，这些参与者如何在空间上组织和协调功能尚不清楚。在这里，我们确定支架蛋白 Big bang 是一种通过确保适当的连接张力来调节翅膀盘状上皮细胞生长的新型调节剂。Big bang 的缺失会导致非肌肉肌球蛋白的调节轻链 Spaghetti squash 的减少。这与顶表面增加、连接张力降低和翅膀变小有关。引人注目的是，通过表达组成型激活的 Spaghetti squash 可以挽救 突变盘的这些表型特征。Big bang 与 Spaghetti squash 在顶细胞皮质中共定位，并存在于相同的蛋白质复合物中。这些结果表明，在发育中的翅膀的上皮细胞中，支架蛋白 Big bang 控制着细胞顶皮质的组织，这对于调节细胞形状和组织生长很重要。
