FIGURE 1:

Osh proteins regulate PI4P distribution in cells. (A) Localization of GFP-PH^FAPP1 in osh1-7Δ /CEN OSH4 cells or osh1-7Δ /CEN osh4^ts cells at indicated temperatures. Cells were grown overnight at 25°C in a synthetic medium containing 2% glucose and then shifted to 37°C for 1 h. Cells shown are representative of >100 cells observed. Note that 6 and 55% of osh1-7Δ/CEN osh4^ts cells showed polarized localization of GFP-PH^FAPP1 at 25 and 37°C, respectively, and 6 and 0% of osh1-7Δ/CEN OSH4 cells showed polarized localization of GFP-PH^FAPP1 at 25 and 37°C, respectively. Scale bar, 5 μm. (B) Localization of GFP-PH^FAPP1 and FM4-64 in osh1-7Δ/CEN osh4^ts cells at 37°C. Cells were grown overnight at 25°C in a synthetic medium containing 2% glucose and then shifted to 37°C for 1 h. FM4-64 was added to cells and kept on ice to label the plasma membrane. Scale bar, 5 μm. (C) The PI4P probe GFP-2xPH^Osh2 accumulates at polarized growth sites in sec6^ts cells at the nonpermissive temperature. Wild-type and sec6^ts cells were grown overnight at 25°C in a synthetic medium containing 2% glucose and then shifted to 37°C for 15 min. Cells shown are representative of >100 cells observed. Scale bar, 5 μm.