Yeast stress granules are sensitive to cycloheximide, and stimulated by a constitutively active allele of the GCN2 kinase. (A) Log-phase yRP840 cells transformed with pRP1659 were glucose deprived and examined. Cycloheximide-treated cells (100 μg/ml) were preincubated with the drug for 1 min before harvest. (B) Cells identical to those in A were subject to the following stresses. Oxidative stress: shift to SC media containing 3 mM H₂O₂ or a mock treatment (H₂O) for 15 min. Hyperosmotic stress: shift to SC media containing 1 M KCL for 15 min. Hypotonic stress: shift to H₂O containing 2% dextrose for 15 min. SC media was used as a mock osmotic control. (C) Cells similar to those in A, but additionally transformed with either pRP1663 (Gcn2c) or pRS416 (empty vector control) were glucose deprived and examined for altered stress granule/P-body assembly.