Exchange controls coarsening of surface condensates

TL;DR

This paper investigates how surface exchange processes influence the growth and patterning of biological membrane condensates, revealing that exchange dynamics significantly impact coarsening and pattern complexity.

Contribution

It introduces a thermodynamically consistent model showing passive and active exchange effects on surface condensate coarsening, linking transport mechanisms to pattern formation.

Findings

Passive exchange accelerates coarsening

Active exchange can arrest or complexify patterns

Transport via bulk diffusion explains observed scaling laws

Abstract

Biological membranes often exhibit heterogeneous protein patterns, which cells control. Strong patterns, like the polarity spot in budding yeast, can be described as surface condensates, formed by physical interactions between constituents. However, it is unclear how these interactions affect the material exchange with the bulk. To study this, we analyze a thermodynamically consistent model, which reveals that passive exchange generally accelerates the coarsening of surface condensates. Active exchange can further accelerate coarsening, although it can also fully arrest it and induce complex patterns involving various length scales. We reveal how these behaviors are related to non-local transport via diffusion through the bulk, rationalizing the various scaling laws we observe and allowing us to interpret biologically relevant scenarios.