FIGURE 4:

Ccq1-Tpz1^TPP1 interaction is required to prevent checkpoint activation. (A) Microscopic analysis of early generation (20–40 cell divisions) wild-type (wt), ccq1Δ, and various indicated ccq1 point mutant cells grown in liquid YES culture. White scale bar: 10 μm. (B) Western blot analysis of Chk-myc for indicated strains. Wild-type cells were also exposed to 100 Gy of gamma irradiation to induce DNA damage and Chk1 phosphorylation (*). (C) Effect of disrupting Ccq1-Tpz1^TPP1 interaction on telomere association for Rad26^ATRIP, monitored by ChIP assays. Error bars represent SEM from at least three experimental replicates. Statistical analysis of ChIP data by two-tailed Student’s t test is shown in Supplemental Table S4. Expression level of myc-tagged Rad26 was monitored by Western blot analysis. Anti-Cdc2 blot served as loading control.