Figure 5. Overexpression of CLB5 impairs the localization of Stu2 on spindle and cytoplasmic microtubules.

A. stu2-10 temperature-sensitive mutants suppress the growth defect of swe1Δ cells overexpressing CLB2. The cell cultures with indicated genotypes were 10-fold diluted and then spotted onto glucose and galactose plates. The growth was examined after 4 day incubation at 25°C. B. Overexpression of CLB5 is toxic to stu2-10 mutants. The growth of WT and stu2-10 mutant cells with a control vector or P_GALCLB5 plasmids at 25°C were examined as described in A. C. spc110^18A91A mutants partially suppress the temperature sensitivity and spindle elongation defects of stu2-10 mutants. The growth of cells with the indicated genotypes at 25°C and 35°C is shown in the top panel. The cells with indicated genotypes were arrested at G₁ phase at 25°C and then released into YPD medium at 35°C. The budding index and the percentage of cells with an elongated spindle (>3 µm) are shown in the bottom panel (n>100). D. Overexpression of CLB5 impairs the localization of Stu2 on spindle and cytoplasmic microtubules. WT and spc110^18A91A cells with STU2-GFP TUB1-mApple harboring a control vector or a P_GALCLB5 plasmid were arrested with 200 mM HU in raffinose medium for 2.5 hrs. After the cells were released into galactose medium for 1 hr, they were subjected to live-cell microscopy at 25°C. The Stu2 localization and spindle morphology are shown (a reprehensive from more than 10 cells). The scale bar is 5 µm.