Viscoelasticidad y propiedades de la interfaz de los condensados multicomponente rigen la secuestración de...

Stress granules (SGs) are multi-component protein-RNA condensates widely viewed as crucibles for fibril formation in neurodegenerative diseases such as amyotrophic lateral sclerosis. Here, we test this model by examining whether SG-mimics promote or suppress amyloid formation. Using multi-component programmable peptide-nucleic acid condensates, we show that condensates delay amyloid assembly by sequestering soluble proteins, and that fibrils grow in the dilute phase. Systematic tuning of condensate material properties reveals two key modulating mechanisms: the density of fibril-forming proteins at condensate interfaces dictates the lag phase of fibril assembly, and condensate viscoelasticity regulates protein efflux-driven fibril growth. These principles extend to SG-mimic condensates formed by G3BP1 and RNA, suggesting that SGs may function as potent suppressors rather than crucibles of pathological amyloid assembly.