美国耶鲁大学Murrell, Michael团队揭示了F-肌动蛋白组织和主动应激之间的反馈决定了细胞骨架的临界性和能量定位。相关论文于2025年6月18日发表在《自然—物理学》杂志上。

自组织临界性可能发生在地震、雪崩和生物过程中，其特征是间歇性、无标度的能量耗散。在活细胞中，肌动蛋白细胞骨架经历动态的结构重组，特别是在迁移和分裂过程中，分子马达产生机械应力，驱动大的耗散事件。然而，控制这些关键转变的机制尚不清楚。研究组表明细胞骨架临界性是由F-肌动蛋白组织和主动应激产生之间的相互作用引起的。该研究侧重于体外最小肌动球蛋白系统，该系统由F-肌动蛋白丝、肌球蛋白II马达和成核促进因子组成。 

通过系统地改变肌动蛋白的连接性和向列序，研究组证明有序和稀疏连接的网络表现出指数应力耗散，而无序和高度连接的网络则表现出能量释放的重尾分布和自组织临界性的1/f噪声特征。无序的增加导致应力局部化，将力传播转变为更硬的机械模式，让人想起凝聚态系统中的安德森局部化。此外，研究组发现网络结构直接调节肌球蛋白II丝的大小，建立了一个调节临界性的化学-机械反馈回路。该发现为集体细胞骨架动力学、能量定位和细胞自组织提供了见解。

附：英文原文

Title: Feedback between F-actin organization and active stress governs criticality and energy localization in the cell cytoskeleton

Author: Sun, Zachary Gao, Zimmerberg, Nathan, Kelly, Patrick, Floyd, Carlos, Papoian, Garegin, Murrell, Michael

Issue&Volume: 2025-06-18

Abstract: Self-organized criticality can occur in earthquakes, avalanches and biological processes, and is characterized by intermittent, scale-free energy dissipation. In living cells, the actin cytoskeleton undergoes dynamic structural reorganization, particularly during migration and division, where molecular motors generate mechanical stresses that drive large dissipative events. However, the mechanisms governing these critical transitions remain unclear. Here we show that cytoskeletal criticality emerges from the interplay between F-actin organization and active stress generation. Our study focuses on a minimal actomyosin system in vitro, which is composed of F-actin filaments, myosin II motors and nucleation-promoting factors. By systematically varying the actin connectivity and nematic order, we demonstrate that ordered and sparsely connected networks exhibit exponential stress dissipation, whereas disordered and highly connected networks show heavy-tailed distributions of energy release and the 1/f noise characteristic of self-organized criticality. Increased disorder leads to stress localization, shifting force propagation into stiffer mechanical modes, reminiscent of Anderson localization in condensed-matter systems. Furthermore, we show that network architecture directly regulates the myosin II filament size, establishing a chemical–mechanical feedback loop that modulates criticality. Our findings provide insights into the collective cytoskeletal dynamics, energy localization and cellular self-organization.

DOI: 10.1038/s41567-025-02919-4

Source: https://www.nature.com/articles/s41567-025-02919-4