Mechano-dependent sorbitol accumulation supports biomolecular condensate

Condensed droplets of protein regulate many cellular functions, yet the physiological conditions regulating their formation remain largely unexplored. Increasing our understanding of these mechanisms is paramount, as failure to control condensate formation and dynamics can lead to many diseases. Here, we provide evidence that matrix stiffening promotes biomolecular condensation in vivo. We demonstrate that the extracellular matrix links mechanical cues with the control of glucose metabolism to sorbitol. In turn, sorbitol acts as a natural crowding agent to promote biomolecular condensation. Using in silico simulations and in vitro assays, we establish that variations in the physiological range of sorbitol concentrations, but not glucose concentrations, are sufficient to regulate biomolecular condensates. Accordingly, pharmacological and genetic manipulation of intracellular sorbitol concentration modulates biomolecular condensates in breast cancer-a mechano-dependent disease. We propose that sorbitol is a mechanosensitive metabolite enabling protein condensation to control mechano-regulated cellular functions.