Many cellular processes, such as cell division^1,2,3, cell motility⁴, wound healing⁵ and tissue folding^6,7, rely on the precise positioning of proteins on the membrane. Such protein patterns emerge from a combination of protein interactions, transport, conformational state changes and chemical reactions at the molecular level⁸. Recent experimental and theoretical work clearly demonstrates the role of geometry, including membrane curvature^9,10,11 and local cytosolic-to-membrane ratios^12,13, and advective cortical flow in modulating membrane protein patterns. However, it remains unclear how these proteins achieve robust spatiotemporal organization on the membrane during the dynamic cell shape changes involved in physiological processes. Here we use oocytes of the starfish Patiria miniata as a model system to elucidate a shape-adaptation mechanism that robustly controls spatiotemporal protein dynamics on the membrane in spite of cell shape deformations. By combining experiments with biophysical theory, we show how cell shape information contained in a cytosolic gradient can be decoded by a bistable regulator of the enzyme Rho, which is associated with contractility. This bistable front in turn controls a mechanochemical response by locally triggering excitable dynamics of Rho. We posit that such a shape-adaptation mechanism based on a hierarchy of protein patterns may constitute a general physical principle for cell shape sensing and control.

许多细胞过程，例如细胞分裂^1,2,3，细胞运动⁴，伤口愈合⁵和组织折叠^6,7，都依赖于蛋白质在膜上的精确定位。这种蛋白质模式来自蛋白质相互作用、运输、构象状态变化和分子水平的化学反应的组合⁸。最近的实验和理论工作清楚地证明了几何学的作用，包括膜曲率^9,10,11和局部胞质与膜的比率^12,13和调节膜蛋白模式的平流皮层流动。然而，尚不清楚这些蛋白质如何在生理过程中涉及的动态细胞形状变化期间在膜上实现强大的时空组织。在这里，我们使用海星Patiria miniata的卵母细胞作为一个模型系统来阐明一种形状适应机制，尽管细胞形状变形，该机制仍能稳健地控制膜上的时空蛋白质动力学。通过将实验与生物物理理论相结合，我们展示了细胞溶质梯度中包含的细胞形状信息如何被与收缩性相关的酶 Rho 的双稳态调节器解码。这种双稳态前沿反过来通过局部触发 Rho 的可兴奋动力学来控制机械化学反应。我们假设这种基于蛋白质模式层次结构的形状适应机制可能构成细胞形状感知和控制的一般物理原理。