Figure 5.

In vti1-2 cells newly synthesized ALP localizes to the vacuole at 24°C but remains in vesicles at 35°C. Expression of ALP was placed under the control of the GAL1 promoter in vti1-2 cells. ALP expression was induced for 1 h at 24°C or simultaneously with a shift to 35°C, and cells were prepared for indirect immunofluorescence. At 24°C ALP antibodies stained ring-like structures, which were identified as vacuoles by the indentations in the differential interference contrast picture (DIC, arrowheads). At 35°C ALP staining was not vacuolar but very diffuse, which is a pattern typical of vesicles. For comparison, ALP staining in wild-type cells (WT) is shown.