Fig. 4. Relationship between Cdk5 and Bem1. (A) cdc24-GFP (UMI29) and cdk5^ts cdc24-GFP (UMI30) cells were grown in CMD at 34°C for 4 hours. Cell tip association of Cdc24-GFP is dependent on Cdk5 function. (B) bem1-GFP (UMI64) and cdk5^ts bem1-GFP (UMI65) were grown as in A. Note that Bem1-GFP localization in the tip was independent of Cdk5 function. (C) cdk5^ts (SONU99), P_crg1:bem1 cdk5^ts (UMP78) and P_crg1:cdc24 cdk5^ts (UMP82) cells were grown in YPA at 34°C for 6 hours and 21 hours. cdk5^ts cells were lysed after 21 hours at 34°C. Overexpression of bem1 and cdc24 in cdk5^ts cells rescued the polarity loss defect typical of cdk5^ts cells. (D) Data from C after 6 hours of growth. bem1 and cdc24 overexpression in cdk5^ts cells resulted in 90% and 96% of polarized cells, respectively. 100 cells were scored in each of 2 independent experiments. Results are mean ± s.d. Scale bars: 15 µm.