Figure 4.

TRAPPIII plays a major role in Ypt1 activation at the Golgi in vivo. (A, left) Localization of plasmid-borne GFP-Ypt1 relative to the late Golgi/TGN marker Sec7-6×DsRed in WT versus trs85Δ mutant cells grown at 30°C. (A, right) Line-trace quantification of Golgi and cytosolic Ypt1 in WT versus trs85Δ cells. Error bars represent 95% CIs. n ≥ 15 cells. (B, left) Localization of plasmid-borne GFP-Ypt6 relative to Sec7-6×DsRed in WT versus trs85Δ mutant cells. (B, right) Line-trace quantification of Golgi and cytosolic Ypt6 in WT versus trs85Δ cells. Error bars represent 95% CIs. n ≥ 15 cells. (C) Schematic depicting the anchor-away method used to conditionally deplete TRAPPIII activity in cells. (D, left) Localization of GFP-Ypt1 in untreated cells versus cells treated with rapamycin to relocalize Trs85 to the PM. (Right) Quantification of Golgi and cytosolic Ypt1 in untreated versus rapamycin-treated cells. Error bars represent 95% CIs. n ≥ 12 cells. ***, P < 0.001 for unpaired two-tailed t test with Welch’s correction. Dashed lines represent cell boundaries. Bars, 2 µm. DIC, differential interference contrast.