Crowder Chain\nLength Variability and Excluded Volume\nEffect on the Phase Separation Behavior of Mucin

Phase separation within cellular membranes, a critical\nprocess\nunderpinning diverse cellular functions, is significantly influenced\nby transmembrane proteins. Therefore, elucidating the behavior of\na transmembrane protein in its phase-separated state is of utmost\nimportance. Our study explores mucin behavior in the cellular milieu,\naiming to determine the role of crowder chain length and excluded\nvolume in phase separation. Confocal microscopy images demonstrate\nthe strong partitioning of mucin into the condensed phase influenced\nby hydrophobic and electrostatic interactions. Fluorescence recovery\nafter photobleaching analysis revealed increased mobility in the\npresence of shorter chain length crowders, indicating the dynamic\nbehavior of protein within condensed phases. Excluded volume calculation\nusing the theoretical model emphasizes its importance in mucin phase\nseparation under crowded conditions. Our findings underscore the ability\nof mucin to phase-separate under crowded conditions, highlighting\nthe crucial role of excluded volume and enhancing our understanding\nof its involvement in cancer progression.