Figure 5.

Requirement of Bbp1p, but not Mps2p, for proper localization of Cdc5p at the SPB. (A) Strain KLY3546 (BBP1), KLY3791 (bbp1-1), or KLY3729 (mps2-1), which expresses Cdc5p-GFP under endogenous CDC5 promoter control was cultured overnight at 23°C and then shifted to 34°C in the presence of 15 μg/ml of nocodazole for 3 h. Among the large-budded cells, the fraction of cells with Cdc5p-GFP signals at the SPB were determined by counting >200 cells for each sample. These results are obtained from three independent experiments. Error bars indicate SD. WT, strain KLY3546; bbp1-1, strain KLY3791; mps2-1, strain KLY3729. (B and C) To examine the temperature-dependent localization of Bbp1p and bbp1-1p to the SPB, strains KLY5336 and KLY5334, which expresses Bbp1p-GFP or bbp1-1p-GFP under endogenous BBP1 promoter control, respectively, were arrested with nocodazole for 2.5 h. Cells were then shifted to 37°C for 1.5 h, fixed, and then examined by confocal microscopy (B). Localization of Spc42p-GFP in the BBP1 wild-type (KLY3685) or the bbp1-1 mutant (KLY3692) was also examined under the same conditions. More than 200 cells were counted in three independent experiments. Error bars indicate SD. Bar, 5 μm.