FIGURE 3:

Rad53 can be phosphorylated in response to replication stress in the absence of 9-1-1 and Dpb11. (A) Strains with the indicated genotype were grown asynchronously and then treated with 0.2 M HU for 4 h at 22.5°C. All strains carry the sml1-1 mutation, which suppresses lethality of a mec1∆. Rad53 phosphorylation was visualized by SDS–PAGE and Western blot. Cdc28 serves as a loading control. (B) After HU treatment as described in A for the indicated time, HU was washed out and cells plated on rich medium to determine viability. The mean of three independent experiments is plotted; error bars reflect SE. (Error bars that cannot be seen are thinner than the line.)