BPS2026 – Sequence-encoded molecular switches control condensate formation in plant stress proteins

Biomolecular condensates (droplet-like assemblies) formed via liquid-liquid phase separation (LLPS) play a vital role in cellular stress responses. Yet the sequence “grammar” that regulates LLPS in plant proteins remains poorly understood. To address this gap, we examine how the sequence and structural features of plant intrinsically disordered proteins (IDPs) influence condensate formation. Using the Arabidopsis companion of cellulose synthase proteins (CC1 and CC2) as a model system, we used extensive multiscale coarse-grained molecular dynamics (MD) simulations and systematic sequence analyses approach to investigate why highly similar N-terminal domains of these proteins exhibit differential phase behavior under stress conditions. Our computational approach is designed to identify critical sequence signatures and key chemical interactions that could act as molecular switches controlling condensate formation. These findings aim to provide mechanistic insights into how plants regulate condensate formation during environmental stress and to establish a foundation for understanding sequence-encoded phase-separation rules in plant systems. More broadly, this work seeks to advance our knowledge of how plant’s cellular organization and stress adaptation are regulated by intrinsically disordered regions.