Figure 3.

SUA5 deletion does not affect telomerase expression and assembly. (A) SUA5 deletion does not increase the telomere shortening rate in the telomerase-deficient cells. The isogenic strain of est1Δ or est1Δ sua5Δ was continuously passaged and the genomic DNAs were digested with XhoI and subjected to telomere blot. (B) SUA5 is required for the elevated gross chromosomal rearrangements (GCRs) rates observed in pif1Δ cells. GCR rates in pif1Δ, sua5Δ and pif1Δsua5Δ strains were analysed as reported (Myung et al, 2001). (C) The protein levels of telomerase components and Cdc13p are not affected by SUA5. The Myc-tagged proteins were examined by western blot with an anti-Myc antibody. The triangle (Δ) indicates unknown proteins cross-reacted with the antibody, which also serve as loading controls. The asterisked (^*) bands might be the degradation products of Cdc13p. (D) The expression of TLC1 is not affected by SUA5. Northern blot analysis of total RNAs from the indicated strains with TLC1 and snoRNA probes. (E) Sua5p is not associated with TLC1. The myc-tagged proteins were immunoprecipitated with the anti-myc antibody, and TLC1 was detected with semiquantitative PCR. (F) SUA5 is not involved in TLC1 biogenesis. TLC1 RNA was over-expressed under the control of GPD promoter. The mtr10Δ mutant, which has a defect in TLC1 trafficking, serves as a positive control. (G) SUA5 does not affect telomerase assembling. The myc-tagged Est2p was immunoprecipitated, and co-immunoprecipitated TLC1 was detected with semiquantitative PCR.