Fig 7. The RTD and nuclear surveillance pathways are each involved in tRNA_i^Met(CAU) quality control in S. cerevisiae trm6-504 mutants.

(A) The S. cerevisiae trm6-504 mutant growth defect is substantially suppressed by mutations in individual components of the RTD and nuclear surveillance pathways. Strains were grown overnight in YPD media at 30°C and analyzed for growth on indicated plates and temperatures. (B) tRNA_i^Met(CAU) levels are substantially restored in S. cerevisiae trm6-504 strains with mutations in individual components of the RTD and nuclear surveillance pathways. Strains were grown in YPD at 27°C and shifted to 34°C for 6 hours as described in Materials and Methods, and RNA was isolated and analyzed by northern blotting. (C) Quantification of tRNA_i^Met(CAU) levels in S. cerevisiae trm6-504 strains with mutations in the RTD and nuclear surveillance pathways. Dark and light colors indicate growth at 27°C and 34°C.