Figure 3. A GTP-bound Gtr1 mutant suppresses autophagy in a Gtr2-dependent manner. gtr1∆ gtr2∆ double-deletion cells (SKY167) harboring empty vector (-), plasmid encoding GTP-bound mutant Gtr1 (GTP), and/or plasmid encoding wild-type (WT) or GDP-bound mutant Gtr2 (GDP) and tco89∆ gtr1∆ gtr2∆ triple-mutant cells (SKY277) expressing GTP-bound Gtr1 mutant (GTP) and GDP-bound Gtr2 mutant (GDP) were grown in SD medium containing 0.5% casamino acids, incubated under nitrogen-starvation conditions for 3 h, and then subjected to ALP assays. Data represent means ± standard deviation from 3 independent experiments. The ALP activities of wild-type (SKY084) and pep4∆ (SKY100) cells harboring empty vector were also measured as control samples.