Stress granules (SG) are droplets of proteins and RNA that form
in the cell cytoplasm during stress conditions. We consider minimal models of
stress granule formation based on the mechanism of phase separation regulated
by ATP-driven chemical reactions. Motivated by experimental observations, we
identify a minimal model of SG formation triggered by ATP depletion. Our
analysis indicates that ATP is continuously hydrolysed to deter SG formation
under normal conditions, and we provide specific predictions that can be tested
experimentally.