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)i-var2 strain has increased levels of tRNA^Ile(UAU) and undergoes little obvious decay of tRNA^Ile(UAU). (A) Northern analysis of an S. pombe pus1Δ tI(UAU)i-var2 strain after temperature shift. The S. pombe pus1Δ tI(UAU)i-var2 strains and control strains as indicated were grown 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. The image is from a single gel after transfer and hybridization to the indicated probes; small squares at the bottom indicate where the images were spliced to remove lanes not shown. (B) Quantification of levels of tRNA^Ile(UAU), tRNA^Ala(AGC), and unspliced pre-tRNA^Ile(UAU) in S. pombe WT and pus1Δ strains at 38.5°C. The statistical significance was evaluated as in Figure 3B.