Figure 1.
ALP traffic is defective in vti1-2 but not in vti1-1 cells at the restrictive temperature. ALP transport was followed in wild-type, vti1-1, and vti1-2 cells at 24 and 36°C after a 15-min preincubation at 36°C. Cells were labeled for 7 min with 35S-Met/-Cys and chased for 0–60 min. ALP was immunoprecipitated from cellular extracts and separated by SDS-PAGE. In vti1-1 cells pALP is processed to the vacuolar mALP at both temperatures with wild-type kinetics. ALP matures in vti1-2 cells at 24°C. By contrast, at 36°C pALP predominates even after a 60-min chase in vti1-2 cells, indicating that ALP traffic to the vacuole is blocked.