FIGURE 1: Mec1-dependent Rad53 phosphorylation is defective in cdc13Δ cells.

(A) Terminal chromosomal regions were amplified by PCR and sequenced. Telomeric DNA (in bases) present on the amplified fragments is indicated. A total of 17 independent sequences were obtained, with two of them ending in the subtelomeric Y’ element.

(B) Exponentially growing wild-type (wt), Survivor (S) or cdc13Δ (cdc13Δ) cells were left untreated or were treated with phleomycin for 2 h. Protein extracts were prepared and analyzed by western blotting with an anti-Rad53 antibody.

(C) As in (B) except that cells also lacked the TEL1 gene as indicated in the Survivors (S) and Cdc13-independent (cdc13Δ) cells. Cells were left untreated or were treated with phleomycin for 2 h.