Terenna Courtney R, Makushok Tatyana, Velve-Casquillas Guilhem, Baigl Damien, Chen Yong, Bornens Michel, Paoletti Anne, Piel Matthieu, Tran Phong T
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Curr Biol. 2008 Nov 25;18(22):1748-53. doi: 10.1016/j.cub.2008.09.047.
The cylindrical rod shape of the fission yeast Schizosaccharomyces pombe is organized and maintained by interactions between the microtubule, cell membrane, and actin cytoskeleton [1]. Mutations affecting any components in this pathway lead to bent, branched, or round cells [2]. In this context, the cytoskeleton controls cell polarity and thus dictates cell shape. Here, we use soft-lithography techniques to construct microfluidic channels to control cell shape. We show that when wild-type rod-shaped cells are physically forced to grow in a bent fashion, they will reorganize their cytoskeleton and redirect cell polarity to make new ectopic cell tips. Moreover, when bent or round mutant cells are physically forced to conform to the wild-type rod-shape, they will reverse their mutational phenotypes by reorganizing their cytoskeleton to maintain proper wild-type-like localization of microtubules, cell-membrane proteins, and actin. Our study provides direct evidence that the cytoskeleton controls cell polarity and cell shape and demonstrates that cell shape also controls the organization of the cytoskeleton in a feedback loop. We present a model of the feedback loop to explain how fission yeast maintain a rod shape and how perturbation of specific parameters of the loop can lead to different cell shapes.
裂殖酵母粟酒裂殖酵母的圆柱形杆状形态是由微管、细胞膜和肌动蛋白细胞骨架之间的相互作用组织和维持的[1]。影响该途径中任何成分的突变会导致细胞弯曲、分支或呈圆形[2]。在这种情况下，细胞骨架控制细胞极性，从而决定细胞形状。在这里，我们使用软光刻技术构建微流体通道来控制细胞形状。我们表明，当野生型杆状细胞被迫以弯曲的方式生长时，它们会重新组织其细胞骨架并重新引导细胞极性以形成新的异位细胞尖端。此外，当弯曲或圆形突变细胞被迫符合野生型杆状时，它们会通过重新组织其细胞骨架来维持微管、细胞膜蛋白和肌动蛋白的适当野生型样定位，从而逆转其突变表型。我们的研究提供了直接证据，证明细胞骨架控制细胞极性和细胞形状，并证明细胞形状也在反馈回路中控制细胞骨架的组织。我们提出了一个反馈回路模型，以解释裂殖酵母如何维持杆状形态以及回路特定参数的扰动如何导致不同的细胞形状。
