Schizosaccharomyces pombe pus1 mutants are temperature sensitive due to decay of tRNA^Ile(UAU) by the 5′-3′ exonuclease Dhp1, primarily targeting the unspliced pre-tRNA

A pus1Δ tI(UAU)-iΔ strain and a pus1Δ tI(UAU)-U27C strain undergo little tRNA^Ile(UAU) decay, and the control pus1Δ tI(UAU)-WT strain accumulates unspliced pre-tRNA^Ile(UAU). (A) Northern analysis of S. pombe WT and pus1Δ strains with tI(UAU) variants. Strains as indicated were grown in biological replicates in YES media at 30°C and shifted to 38.5°C for 6 h, and then RNA was isolated and analyzed by Northern blotting, as in Figure 2A. (B) Quantification of levels of tRNA^Ile(UAU) and tRNA^Ala(AGC) in S. pombe WT and pus1Δ strains at 38.5°C. The statistical significance was evaluated as in Figure 3B. (C) Quantification of levels of unspliced pre-tRNA^Ile(UAU) and unspliced pre-tRNA^Arg(CCU) in S. pombe WT and pus1Δ strains at 38.5°C. The statistical significance was evaluated as in Figure 3B.