Department of Biology, Reed College, Portland, OR 97202.
Department of Biology and Carolina Center for Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280.
Mol Biol Cell. 2022 May 1;33(5):ar19. doi: 10.1091/mbc.E21-09-0434. Epub 2022 Mar 2.
The spectraplakin family of proteins includes ACF7/MACF1 and BPAG1/dystonin in mammals, VAB-10 in in zebrafish, and Short stop (Shot), the sole member. Spectraplakins are giant cytoskeletal proteins that cross-link actin, microtubules, and intermediate filaments, coordinating the activity of the entire cytoskeleton. We examined the role of Shot during cell migration using two systems: the in vitro migration of tissue culture cells and in vivo through border cell migration. RNA interference (RNAi) depletion of Shot increases the rate of random cell migration in tissue culture cells as well as the rate of wound closure during scratch-wound assays. This increase in cell migration prompted us to analyze focal adhesion dynamics. We found that the rates of focal adhesion assembly and disassembly were faster in Shot-depleted cells, leading to faster adhesion turnover that could underlie the increased migration speeds. This regulation of focal adhesion dynamics may be dependent on Shot being in an open confirmation. Using border cells as an in vivo model for cell migration, we found that RNAi depletion led to precocious border cell migration. Collectively, these results suggest that spectraplakins not only function to cross-link the cytoskeleton but may regulate cell-matrix adhesion.
spectraplakins 蛋白家族包括哺乳动物中的 ACF7/MACF1 和 BPAG1/dystonin、斑马鱼中的 VAB-10 以及唯一的成员 Short stop (Shot)。spectraplakins 是一种巨大的细胞骨架蛋白，可将肌动蛋白、微管和中间丝交联在一起，协调整个细胞骨架的活性。我们使用两种系统研究了 Shot 在细胞迁移中的作用：体外培养细胞的迁移和体内通过边缘细胞迁移。Shot 的 RNA 干扰 (RNAi) 耗尽增加了组织培养细胞中随机细胞迁移的速度以及划痕实验中伤口闭合的速度。细胞迁移的增加促使我们分析粘着斑动力学。我们发现，Shot 耗尽的细胞中粘着斑的组装和拆卸速度更快，导致更快的粘着斑周转，这可能是迁移速度加快的基础。这种粘着斑动力学的调节可能依赖于 Shot 处于开放的构象。使用 边缘细胞作为细胞迁移的体内模型，我们发现 RNAi 耗尽导致边缘细胞过早迁移。总的来说，这些结果表明 spectraplakins 不仅起到交联细胞骨架的作用，还可能调节细胞-基质黏附。
