Quantitative theory for the diffusive dynamics of liquid condensates

eLife

Jonathan Bauermann¹  Stefano Bo¹  Louise M Jawerth²  Lars Hubatsch³  Christoph A Weber³  Celina Love⁴  TY Dora Tang⁴  Anthony A Hyman⁵ 

[1] Max Planck Institute for the Physics of Complex Systems, Dresden, Germany;Max Planck Institute for the Physics of Complex Systems, Dresden, Germany;Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany;Max Planck Institute for the Physics of Complex Systems, Dresden, Germany;Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany;Center for Systems Biology Dresden, Dresden, Germany;Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany;Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany;Center for Systems Biology Dresden, Dresden, Germany;

关键词: phase separation;    FRAP;    quantitative modelling;    None;   

DOI  :  10.7554/eLife.68620

来源: eLife Sciences Publications, Ltd

【 摘 要 】

Key processes of biological condensates are diffusion and material exchange with their environment. Experimentally, diffusive dynamics are typically probed via fluorescent labels. However, to date, a physics-based, quantitative framework for the dynamics of labeled condensate components is lacking. Here, we derive the corresponding dynamic equations, building on the physics of phase separation, and quantitatively validate the related framework via experiments. We show that by using our framework, we can precisely determine diffusion coefficients inside liquid condensates via a spatio-temporal analysis of fluorescence recovery after photobleaching (FRAP) experiments. We showcase the accuracy and precision of our approach by considering space- and time-resolved data of protein condensates and two different polyelectrolyte-coacervate systems. Interestingly, our theory can also be used to determine a relationship between the diffusion coefficient in the dilute phase and the partition coefficient, without relying on fluorescence measurements in the dilute phase. This enables us to investigate the effect of salt addition on partitioning and bypasses recently described quenching artifacts in the dense phase. Our approach opens new avenues for theoretically describing molecule dynamics in condensates, measuring concentrations based on the dynamics of fluorescence intensities, and quantifying rates of biochemical reactions in liquid condensates.

【 授权许可】

CC BY