Abstract

Phase separation plays an important organisational role in cells. However, experimental studies of intracellular biomolecular condensates have challenged the standard kinetic theories of phase separation. Specifically, the coarsening rates observed are unexpectedly slow for many intracellular condensates. Partly motivated by the slow fibrillisation kinetics in amyloid formation [1], a conversion-limited scheme of phase separation has recently been proposed to account for the in vivo observation of the slow coarsening kinetics of P granules in C. elegans. [2,3]. In conversion-limited phase separation, the bottleneck of the coarsening rate is the slow conversion of a condensate constituent between the state in the dilute phase and the condensate state, due primarily to the multivalent interactions between the constituents. In this talk, I will first motivate the conversion-limited scheme through a rugged energy landscape picture, and then elucidate its biophysical implications.References:[1] C. F. Lee, J. Loken, L. Jean, and D. J. Vaux, Elongation Dynamics of Amyloid Fibrils: A Rugged Energy Landscape Picture, Phys. Rev. E 80 , 041906 (2009).[2] A. W. Folkmann, A. Putnam, C. F. Lee, and G. Seydoux, Regulation of Biomolecular Condensates by Interfacial Protein Clusters, Science 373, 1218 (2021).[3] C. F. Lee, Scaling Law and Universal Drop Size Distribution of Coarsening in Conversion-Limited Phase Separation, Phys. Rev. Res. 3, 043081 (2021).