Abstract
Cells compartmentalize their components in liquid-like condensates, which can be reconstituted in vitro. Although these condensates interact with membrane-bound organelles, the potential of membrane remodeling and the underlying mechanisms are not well understood. Here, we demonstrate that interactions between protein condensates (including hollow ones) and membranes can lead to remarkable morphological transformations and describe these with theory. Modulation of solution salinity or membrane composition drives the condensate-membrane system through two wetting transitions, from dewetting, through a broad regime of partial wetting, to complete wetting. A new phenomenon, namely fingering or ruffling of the condensate-membrane interface is observed when sufficient membrane area is available, producing intricately curved structures. The observed morphologies are governed by the interplay of adhesion, membrane elasticity, and interfacial tension. Our results highlight the relevance of wetting in cell biology, and pave the way for the design of synthetic membrane-droplet based biomaterials and compartments with tunable properties.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Additional data with two other condensate systems (new Figures S1c,d, S4b, S5b, S8 and S9) using polypeptides are provided as well as evidence for membrane wetting and remolding from literature studies performed on plant cells (new Figure 9). The theoretical model is also extended to explain the conditions, at which membrane ruffling is expected to occur.
