Figure 4.
Exo1 phosphorylation is induced by a range of genomic insults. All strains carried EXO1-myc∷HIS3. (A) A cdc13-1 (DLY1529) and CDC13 yku70Δ strain (DLY3405 and DLY3406), exponentially growing at 23°C, were grown for a further 6 h at 23°C or transferred at higher temperature (36 and 37°C) to induce telomere uncapping. Western blots were performed as in Figure 3 and two different strains with the same genotype, indicated as A and B were examined. (B) cdc13-1 (DLY1529), exponentially growing at 23°C, was transferred to 36°C for 6 h. Left panel: cell cultures of CDC13 cdc9-1 (DLY3262), exponentially growing at 23°C, were transferred to 36°C for 6 h. Right panel: cell cultures of CDC13 (DLY3079) were grown at 23°C in YPD and transferred into YPD with bleomycin (50 μg/ml), samples were taken at 2 h (+) and 4 h (++). Western blots of TCA protein extracts were first probed with anti-Myc antibodies to detect Exo1-Myc. Membranes were stripped and reprobed with anti-Rad53 antibodies.