FIGURE 3:

Internalization of Psy1 depends on actin polymerization. (A) Effect of latrunculin A treatment on Psy1 internalization. A wild-type strain (YN68) expressing GFP-Psy1 was induced to sporulate on SSA at 28°C for 16 h. Cells were resuspended in SSL medium and treated with DMSO (control) or 10 μM latrunculin A (Lat A). F-actin was stained with rhodamine-conjugated phalloidin. The chromatin region was stained with DAPI. Bar, 10 μm. (B) Inhibition of Psy1 internalization in an actin mutant. A temperature-sensitive actin mutant harboring cps8-188 and expressing GFP-Psy1 (ZK118) was induced to sporulate on SSA at 25°C for 16 h and then incubated at 34°C for 5 h. Cells were labeled with FM4-64 in SSL at 34°C for 5 min. The chromatin region was stained with Hoechst 33342. Bar, 10 μm.