Filament Rigidity Vies with Mesh Size in Determining Anomalous Diffusion in Cytoskeleton.

Filament Rigidity Vies with Mesh Size in Determining Anomalous Diffusion in Cytoskeleton. Biomacromolecules. 2019 Nov 05;: Authors: Anderson SJ, Matsuda C, Garamella J, Peddireddy KR, Robertson-Anderson RM, McGorty R Abstract The diffusion of microscopic particles through the cell, important to processes such as viral infection, gene delivery, and vesicle transport, is largely controlled by the complex cytoskeletal network - comprised of semiflexible actin filaments and rigid microtubules - that pervades the cytoplasm. By varying the relative concentrations of actin and microtubules, the cytoskeleton can display a host of different structural and dynamic properties that in turn impact the diffusion of particles through the composite network. Here we couple single-particle tracking with differential dynamic microscopy to characterize the transport of microsphere tracers diffusing through composite in vitro networks with varying ratios of actin and microtubules. We analyze multiple complementary metrics for anomalous transport to show that particles exhibit anomalous subdiffusion in all networks, which our data suggest arises from caging by networks. Further, subdiffusive characteristics are markedly more pronounced in actin-rich networks, which exhibit similarly more prominent viscoelastic properties compared to microtubule-rich composites. While the smaller mesh size of actin-rich composites compared to microtubule rich-composites pl...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research