Local Monomer Levels and Established Filaments Potentiate Non-Muscle Myosin 2 Assembly.
Local Monomer Levels and Established Filaments Potentiate Non-Muscle Myosin 2 Assembly.
复制标题
局部单体水平和已建立的细丝增强非肌肉肌球蛋白 2 的组装。
DOI：
10.1101/2023.04.26.538303
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Beach,JordanR
中科院分区：
文献类型：
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作者：
Quintanilla,MelissaA;Patel,Hiral;Wu,Huini;Sochacki,KemA;Akamatsu,Matthew;Rotty,JeremyD;Korobova,Farida;Bear,JamesE;Taraska,JustinW;Oakes,PatrickW;Beach,JordanR
整个细胞生理学都需要动态组装收缩网络的能力，但在活细胞中缺乏直接的生物物理机制来调控非肌肉肌球蛋白2细丝组装。在这里，我们使用一套动态、定量的成像方法来确定驱动肌球蛋白细丝外观和放大的确定性因素。我们发现，肌动蛋白动力学调节肌球蛋白的组装，但静态肌动蛋白结构扮演的角色不太明确。相反，肌动蛋白网络的重塑通过肌球蛋白：肌球蛋白驱动的相互作用调节局部肌球蛋白单体水平并促进组装。利用光基因控制的肌球蛋白，我们证明了局部浓缩的肌球蛋白足以形成细丝并启动细丝的放大和分割。通过对细丝中肌球蛋白单体的计数，我们展示了肌球蛋白促进的组装过程，该过程在划分为馈送更高阶网络的簇之前建立细丝堆叠。总之，这些发现建立了生物物理机制，调节整个细胞生物学中普遍存在的非肌肉收缩结构的组装。
The ability to dynamically assemble contractile networks is required throughout cell physiology, yet direct biophysical mechanisms regulating non-muscle myosin 2 filament assembly in living cells are lacking. Here, we use a suite of dynamic, quantitative imaging approaches to identify deterministic factors that drive myosin filament appearance and amplification. We find that actin dynamics regulate myosin assembly, but that the static actin architecture plays a less clear role. Instead, remodeling of actin networks modulates the local myosin monomer levels and facilitates assembly through myosin: myosindriven interactions. Using optogenetically controlled myosin, we demonstrate that locally concentrating myosin is sufficient to both form filaments and jump-start filament amplification and partitioning. By counting myosin monomers within filaments, we demonstrate a myosin-facilitated assembly process that establishes filament stacks prior to partitioning into clusters that feed higher-order networks. Together, these findings establish the biophysical mechanisms regulating the assembly of non-muscle contractile structures that are ubiquitous throughout cell biology.