论文标题

运动驱动的对流与拥挤以驱动细胞骨架复合材料中的时空异质运输

Motor-driven advection competes with crowding to drive spatiotemporally heterogeneous transport in cytoskeleton composites

论文作者

Sheung, Janet Y, Garamella, Jonathan, Kahl, Stella K, Lee, Brian Y, McGorty, Ryan J, Robertson-Anderson, Rae M

论文摘要

细胞骨架 - 生物聚合物,分子电机和相关结合蛋白的复合网络 - 是活性物质的范式示例。通过细胞骨架的粒子传输范围从异常和异质延伸到超截止和对流。然而,概括和理解这些特性(对细胞骨架和其他平衡软物质系统的普遍存在)仍然具有挑战性。在这里,我们将光片显微镜与差分动态显微镜和单粒子跟踪相结合,以阐明肌动蛋白 - 微动物复合材料中的异常和对流运输。我们表明,粒子表现出多模式转运,这些传输从明显的细胞扩散到可调的跨界时标。令人惊讶的是,虽然较高的肌动蛋白含量增强了超级产物,但它也显着增加了在短时间内的延伸程度,并且通常会放慢运输速度。相应的位移分布显示了非高斯性,不对称性和非零模式的独特组合,表明有向后的对流以及笼子扩散和跳跃。在较大的时空尺度上,与正常但更快的扩散相比,颗粒通常会随肌球蛋白含量而增加,而没有肌动蛋白。我们的具体结果为活动细胞骨架系统中的非平衡过程,拥挤和异质性之间的相互作用提供了重要的新灯。更一般而言,我们的方法广泛适用于主动物质系统,以阐明跨尺度的运输和动态。

The cytoskeleton -- a composite network of biopolymers, molecular motors, and associated binding proteins -- is a paradigmatic example of active matter. Particle transport through the cytoskeleton can range from anomalous and heterogeneous subdiffusion to superdiffusion and advection. Yet, recapitulating and understanding these properties -- ubiquitous to the cytoskeleton and other out-of-equilibrium soft matter systems -- remains challenging. Here, we combine light sheet microscopy with differential dynamic microscopy and single-particle tracking to elucidate anomalous and advective transport in actomyosin-microtubule composites. We show that particles exhibit multi-mode transport that transitions from pronounced subdiffusion to superdiffusion at tunable crossover timescales. Surprisingly, while higher actomyosin content enhances superdiffusivity, it also markedly increases the degree of subdiffusion at short timescales and generally slows transport. Corresponding displacement distributions display unique combinations of non-Gaussianity, asymmetry, and non-zero modes, indicative of directed advection coupled with caged diffusion and hopping. At larger spatiotemporal scales, particles undergo superdiffusion which generally increases with actomyosin content, in contrast to normal, yet faster, diffusion without actomyosin. Our specific results shed important new light on the interplay between non-equilibrium processes, crowding and heterogeneity in active cytoskeletal systems. More generally, our approach is broadly applicable to active matter systems to elucidate transport and dynamics across scales.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源