Figure 6.

Neither the Cdc13–Est1 interaction (affected in cdc13-2), nor the Yku70–TLC1 interaction, is required for Est2 association at short T₂AG₃ or non-TG ends, yet both contribute to elongation of the T₂AG₃ ends. (A) Analysis by ChIP of the binding of Est2-myc in wild-type or mutant strains (as indicated) at short or long T₂AG₃ ends or non-TG (DSB) ends. Only the increase in telomerase recruitment at both short tracts and the DSB in the yku70-Δ mutant, relative to wild type, is statistically significant (P<0.05 by Mann–Whitney test). (B) ChIP analysis of Rap1 binding (a read-out for telomerase elongation) at short T₂AG₃ ends following HO induction, in tel1-Δ, cdc13-2, yku70-Δ and tlc1-Δ48 strains. All of these mutants display a statistically significant (P<0.05) difference compared with wild type at t=4 h, with cdc13-2 already different at t=2 h. HO constructs, PCR probes, ChIP methods, and statistical analyses were as described in Figures 1 and 2, and in Materials and methods.