Guanosine triphosphatase–activating protein-binding proteins called G3BP1 and G3BP2 function as a core component of stress granules. Stress granules are dynamic assemblages of ribonucleoproteins that form in distressed cells found in tumors or neurodegenerative disease states. G3BP1 also has an unexpected role in tethering the tuberous sclerosis complex (TSC) of proteins to lysosomes. At the lysosome, the TSC regulates a key metabolic regulator called mTORC1. Prentzell et al. detected G3BP1 in a screen for proteins that interact with mTORC1. If G3BP1 levels are low, then mTORC1 becomes hyperactive, stimulating cell motility in tumors or neuronal hyperactivity, which could be bad news for patients.
Cell 184, P655 (2021).
