Effect of REX1 overexpression on 3′ end processing of pre-tRNAUAUIle and pre-tRNATyr under stress. (A) Wild-type strain transformed either with the multicopy vector or the vector containing REX1 was grown in minimal media to exponential phase and then shifted to YPD or YPGly at the indicated temperatures for 2 h. Isolated RNA was analyzed by Northern blotting with probes specific for tRNAUAUIle and tRNATyr. The bottom panels present ethidium bromide–stained 5.8S and 5S rRNA used as the loading controls. Forms of tRNA precursors that accumulate under stress conditions are indicated by solid arrows. (B) Calculation of RNA ratios from at least three biological replicates was performed as described in legend to Figure 1. Standard deviation and P-value calculated by a two-tailed t-test are presented on the graphs; (*) above the bars represent P-value = 0.05.
