Cells expressing GLN3-myc were grown at 23°C to early log phase in glutamine (Gln) or proline (Pro) medium. The cultures were divided, with one half shifted to 37°C and the other half remained at 23°C. Upon incubation for additional 2 hr, cells were treated with rapamycin and collected before (time 0), 30 and 60 min after addition of the drug. Localization of Gln3-myc in the cells was examined by confocal microscopy. The experiment was repeated three times. Percentages of cells with nuclear staining of Gln3-myc expressed as mean ± SD are shown. A. Wild type (Y339), B. tap42-119 mutant (Y351), C. TOR1 tor2-219 (Y511), and D. tor1 tor2-219 mutant (Y442).