Compositional control of FUS condensate ageing through aggregation-prone interaction networks

Competing Molecular Interactions Govern the Dynamical Arrest of G3BP1 Condensates

G3BP1 is a central scaffold of stress granules (SGs). Upon cellular stress, G3BP1 forms complex coacervates with translationally repressed mRNAs and recruits multiple RNA-binding proteins to form reversible biomolecular condensates. Persistent SGs are linked to age-dependent dynamical arrest and impaired disassembly. Here, we employ active and passive nanoscale rheology with optical tweezers to show that G3BP1 condensates evolve from being dominantly viscous fluids to dynamically arrested network glasses characterized by nanoscale caging and elastic memory. Integrating atomistic and coarse-grained simulations with experiments, we find that electrostatic interactions between the oppositely charged intrinsically disordered regions drive condensate ageing. RNA modulates these interactions in a length-and structure-dependent manner, delaying dynamic arrest, whereas Caprin-1 binding to the NTF2L domain has little effect. Together, these findings reveal how competing inter-IDR and IDR–RNA interactions govern condensate ageing and material-state transitions. The findings have broader implications for the regulation of SG dynamics in cells.

The sequence grammar and interactions controlling the aging of protein biomolecular condensates.

This review discusses how features of protein sequence, such as amino acid composition, interaction motifs, and post-translational modifications, influence condensate aging and highlights how interactions with RNA and lipid membranes modulate condensate behavior by altering interaction networks and interfacial properties.

Dual roles of condensates in protein misfolding and aggregation.

The current literature is summarized and biomolecular condensates are described as key regulators of protein misfolding and aggregation and the importance of the local milieu in determining aggregation outcomes is highlighted.

Molecular origins of heterogeneous aging and spatial organization in RNA condensates

From Pan-Life Phase Insights to PhaseHub: Analyzing Protein Condensate Complexity.

Intracellular biomolecular condensation forms multicomponent signaling hubs that regulate development, stress responses, and environmental adaptation. While the molecular grammar encoded within scaffold proteins defines the basal associative features driving condensation, heterotypic condensates are intrinsically dynamic, multicomponent, and far-from-equilibrium systems. Consequently, how condensates organize component composition, stoichiometry, and functional specificity in space and time under physiological conditions remains poorly understood. Addressing this challenge requires integrative frameworks that combine predictive biophysical features with experimental information on protein abundance, interaction networks, subcellular localization, and evolutionary conservation. Here, we first analyzed phase separation (PS) proteins across the Tree of Life in 1,106 species, revealing a stark contrast in computationally predicted phase-separation propensity between eukaryotes and prokaryotes, with genome size as a key determinant. Through a broad analysis of amino acid homorepeat-containing proteins (HRPs) across all species, we uncovered how phase separation evolves via a balance between functional condensation and avoidance of harmful, aggregation-prone sequences. We further identified potential signaling hubs and components across kingdoms by integrating PS-positive proteins with experimentally derived abundance and interactome data from four model eukaryotic species. Using Arabidopsis as a model, we dissect the relationships among PS propensity, condensation hub prediction, HRPs, subcellular localization, and structural conservation. Consequently, we developed PhaseHub (https://phasehub.sbs.ntu.edu.sg/), a user-friendly interface for exploring scaffold-client dynamics, PS components, sequence signatures within each PS protein, and hubs. Our work provides an evolutionary framework for understanding multicomponent PS hubs by integrating molecular grammar with physiological context, thereby facilitating hypothesis generation and rational design.

RNA Modifications Modulate Biomolecular Condensates in Stress and Disease

Biomolecular condensates are dynamic membraneless organelles composed of proteins and RNAs that assemble through multivalent interactions and provide cells with powerful means to regulate gene expression in space and time. Different epitranscriptomic marks such as m6A, m1A, and m5C can reshape RNA structure—binding interfaces and multivalency and, in this manner, tuning which transcripts nucleate or partition into specific condensates and influencing their material state. This review summarizes how individual RNA modifications and their associated proteins regulate the formation and function of BMCs such as stress granules, P-bodies, nuclear bodies and disease-linked condensates in cancer and neurodegeneration. It highlights emerging concepts of combinatorial “epitranscriptomic codes” and bidirectional feedback between condensates and RNA-modifying enzymes and discusses the current experimental and technical gaps that still limit our understanding of modification crosstalk and condensate topology.